Search

Purpose: Composite mesh prostheses incorporate properties of multiple materials for use in open ventral hernia repair (OVHR). This study examines clinical outcomes in patients who underwent OVHR with a polypropylene/expanded polytetrafluoroethylene (ePTFE) composite graft containing a novel polydioxanone (PDO) absorbable ring to facilitate placement and graft positioning., Methods: Data were prospectively collected on consecutive patients undergoing OVHR using a synthetic composite mesh. Seven centers enrolled patients during the study period. All patients underwent a standardized surgical procedure consisting of OVHR with sublay intraperitoneal placement of mesh. Mesh fixation was accomplished with peripheral tacks and transfascial sutures., Results: One hundred and nineteen patients underwent OVHR with the composite mesh. Average age was 55.8 years; there were 71 (59.7 %) females and 48 (40.3 %) males with mean BMI of 33.5 ± 7.1 kg/m(2). One hundred and two (85.7 %) patients presented with primary ventral hernias. Mean defect size was 13.6 cm(2), and mean mesh size was 113.6 cm(2). Most patients (67 %) were discharged the day of surgery. Twelve patients (10.1 %) experienced complications in the perioperative time period primarily consisting of seroma (4.2 %) and ileus (1.7 %). Two patients required reoperation and mesh removal in the early postoperative period for infection and herniorrhaphy site pain, respectively. There was a decline in pain and movement limitation scores between baseline and 1-year follow-up. Six-month (n = 109) and twelve-month (n = 99) follow-up revealed no hernia recurrences (95 % CI 0-3 %, and 0-4 %, respectively)., Conclusions: The use of this second-generation composite mesh was associated with no hernia recurrences and a low complication rate after open ventral hernia repair.

Background: Nonalcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease in the USA. Biopsy has been the standard for determining fibrosis but is invasive, costly, and associated with risk. Previous studies report a calculated "NAFLD fibrosis scores" (cNFS) as a means to overcome the need for biopsy. We compared cNFS versus biopsy-pathological scoring for patients undergoing bariatric surgery., Methods: We retrospectively reviewed patients with available preoperative labs and patient information undergoing Roux-en-Y gastric bypass (RYGBP) surgery at a single institution over a 5.5-year period. Biopsy samples were blind scored by a single hepatopathologist and compared with scores calculated using a previously reported cNFS., Results: Of the 225 patients that met the inclusion criteria, the mean body mass index was 44.6 ± 5.4 kg/m(2) and 85 % were female. Using the cNFS, 39.6 % of patients were categorized into low fibrosis, 52 % indeterminate, and 8.4 % high fibrosis groups. Analysis of fibrosis by pathology scoring demonstrated 2 of 89 (2.2 %) and 7 of 110 (3.4 %) had significant fibrosis in the low and intermediate groups, respectively. Conversely, in the high fibrosis group calculated by cNFS, only 6 of 19 (31.6 %) exhibited significant fibrosis by pathology scoring., Conclusions: No definitive model for accurately predicting presence of NAFLD and fibrosis currently exits. Furthermore, under no circumstances should a clinical "NAFLD fibrosis score" replace liver biopsy at this time for RYGBP patients.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and is most commonly found in the setting of liver cirrhosis. Treatment of HCC must consider both the tumors present, as well as the remaining dysfunctional liver that both hinders treatment and can produce additional HCC over time. Ablation is an evolving part of the multimodality treatment approach to HCC that can effectively destroy tumors while preserving surrounding liver parenchyma. New technologies have made ablation an indispensable tool in the treatment of all stages of HCC. This review presents the history, present technologies and future potential of ablation in the treatment of HCC., Competing Interests: Financial & competing interests disclosure The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. No writing assistance was utilized in the production of this manuscript.

Hepatocellular carcinoma (HCC) is notoriously difficult to treat with systemic chemotherapy. The aim of this study was to evaluate a silica-calcium-phosphate nanocomposite (SCPC75) drug delivery system (DDS) as a means to localize cisplatin treatment within the tumor, while reducing systemic toxicity, in a rat model of HCC. The SCPC75 was prepared and loaded with cisplatin and Fourier transform infrared analyses demonstrated even drug distribution within the SCPC75. A rat model of subcutaneous HCC formation was established and animals treated by either systemic cisplatin injection (sCis) or with SCPC75-Cis hybrid placed adjacent (ADJ) to or within (IT) the tumor. Five days after implantation, 50-55% of the total cisplatin loaded had been released from the SCPC75-Cis hybrids resulting in an approximately 50% decrease in tumor volume compared with sCis treatment. sCis-treated animals exhibited severe side effects, including rapid weight loss and decreased liver and kidney function, effects not observed in SCPC75-Cis-treated animals. Analysis of cisplatin distribution demonstrated drug concentrations in the tumor were 21 and 1.5 times higher in IT and ADJ groups, respectively, compared with sCis-treated animals. These data demonstrate the SCPC75 DDS can provide an effective, localized treatment for HCC with significantly reduced toxicity when compared with systemic drug administration., (Copyright © 2013 Wiley Periodicals, Inc.)

Hepatocellular carcinoma (HCC) is the third most common cause of cancer worldwide and is rising in incidence. Ultrasound is the preferred modality for screening high-risk patients for HCC because it detects clinically significant nodules, widespread availability and lower cost. HCC does not require a biopsy for diagnosis if specific imaging criteria are fulfilled. Transarterial chemoembolization (TACE) is the most common modality used to treat HCC followed by ablation. Cholangiocarcinoma (CCA) is increasing in incidence and the second most common primary malignancy of the liver. There is no effective screening strategy for CCA although magnetic resonance imaging and carbohydrate antigen 19-9 (CA 19-9) are commonly used without proven benefit. Therapy for CCA is challenging and resection, when possible, is the mainstay of therapy. Gemcitabine in combination with cisplatin or biologics may offer a modest survival benefit. Liver transplantation for CCA is associated with reasonable survival in select cases. Molecular diagnostics offer the potential to develop personalized approaches in the management of HCC and CCA.

Objectives: This study was conducted to evaluate differences between 915-MHz and 2.45-GHz microwave ablation (MWA) systems in the ablation of hepatic tumours., Methods: A retrospective analysis of patients undergoing hepatic tumour MWA utilizing two different systems over a 10-month period was carried out., Results: Data for a total of 48 patients with a mean age of 58 ± 1.24 years were analysed. A total of 124 tumours were ablated; 72 tumours were ablated with a 915-MHz system and 52 with a 2.45-GHz system. Mean tumour diameters were 1.7 ± 0.1 cm in the 915-MHz group and 2.5 ± 0.2 cm in the 2.45-GHz group (P < 0.01). Mean ablation time per burn was 8.1 ± 0.3 min in the 915-MHz group and 4.0 ± 0.1 min in the 2.45-GHz group (P < 0.01). The mean number of burns per lesion was 2.0 ± 0.1 in the 915-MHz group and 1.7 ± 0.1 in the 2.45-GHz group (P < 0.05). The mean ablation time per lesion was 9.7 ± 0.7 min in the 915-MHz group, and 6.6 ± 0.6 min in the 2.45-GHz group (P < 0.01). The 2.45-GHz system demonstrated a better correlation between ablation time and tumour size (r(2) = 0.6222) than the 915-MHz system; (r(2) = 0.0696). Mean total energy applied per lesion, and energy applied per cm, were greater with the 915-MHz system (P < 0.05 and P < 0.01, respectively). Total energy applied per lesion was similarly correlated for the 2.45-GHz (r(2) = 0.6263) and 915-MHz (r(2) = 0.7012) systems. Mean total energy applied per cm/min was greater with the 2.45-GHz system (P < 0.05)., Conclusions: Both 915-MHz and 2.45-GHz MWA systems achieve reproducible hepatic tumour ablation. The 2.45-GHz system achieves equivalent, but more predictable and faster ablations using a single antenna system., (© 2013 International Hepato-Pancreato-Biliary Association.)

Ultrasonic thermal energy is commonly used for dissection and vessel ligation. This study compared HARMONIC ACE and Sonicision Cordless Ultrasonic Dissector (SCUD). The devices were used in an in vivo porcine model to coagulate 189 arteries up to 5 mm. Seal times were similar: SCUD, 5.2 ± 1.7 s; ACE, 4.9 ± 1.5 s (P = .20). Burst pressures for SCUD and AVE were 578 ± 284 and 605 ± 288 mm Hg, respectively (P = .48). Stratification by vessel diameter yielded similar results. In all, 17 applications resulted in seal failure on either the proximal or distal side, with no difference between SCUD (4.4%) and ACE (6.6%; P = .37). Histological examination of 48 specimens showed similar thermal spreads: 1.06 ± 0.05 versus 1.08 ± 0.05 mm for SCUD and ACE, respectively (P = .82). In 41 timed mesenteric transections, SCUD required 24.8 ± 4.9 s, which was significantly less than the 33.8 ± 5.4 s for ACE (P < .0001), with no bleeding in either group. SCUD and ACE showed similar vessel seal times, burst pressures, thermal spreads, and seal failure rates. SCUD was more efficient than ACE in mesenteric transection.

Background: Hepatocellular carcinoma (HCC) is a major global health burden. Although chronic, heavy alcohol abuse is an established risk factor for HCC, obesity is emerging as an increasingly important factor in HCC development. Given that other risk factors for HCC act synergistically to promote tumorigenesis, we investigated the effects of diet-induced obesity and chronic ethanol consumption on tumor progression., Methods: A diethylnitrosamine (DEN) mouse model of HCC was established and mice randomized to control (CD; 10 % kcal% fat) or high fat (HFD; 60 % kcal% fat diet) at 5 weeks of age. At 35 weeks, mice were randomized to 10/20 % ethanol (EtOH) in drinking water (alternate days), or drinking water (H2O) alone. Tumor incidence/size were measured and confirmed. Liver tissue was analyzed for oxidative stress and EtOH-metabolizing enzymes and serum analyzed for liver function and nutritional status., Results: DEN treatment induced HCC formation in 60 % CD-H2O mice (6 of 10), an effect exacerbated by HFD (89 %). Tumors in HFD animals occupied significantly more of the liver than mice on CD. EtOH-feeding did not impact HCC incidence or tumor size. HFD resulted in increased liver injury and liver:body weight ratio regardless of EtOH consumption. Increased tumor incidence was associated with elevated hepatic oxidative stress in the absence of changes in intrinsic antioxidant (glutathione) levels., Conclusions: Obesity independently promoted HCC formation in the absence or presence of a known hepatocarcinogen (DEN), and enhanced both number and size of hepatic tumors independent of chronic EtOH consumption in mice.

Background: The use of surgical robots has slowly gained an increasing presence in the realm of hepatobiliary and pancreatic (HPB) surgery. With additional experience, anecdotal evidence has been useful in guiding patient selection for complex robotic procedures. In the following analysis, we reviewed our case series and looked for predictors of conversion in robotic HPB surgery., Methods: We retrospectively reviewed all patients who underwent robotic HPB procedures by a single surgeon at two institutions during March 2006-June 2012. Patient demographics, operative data, procedure type and conversion information were recorded. Trends were analysed for indications for conversion. A subset analysis of robotic-assisted laparoscopic distal pancreatomy was performed and compared with laparoscopic and open distal pancreatectomy during the same time period by the same surgeon., Results: During this time period, 77 patients underwent robotic hepatobiliary and pancreatic procedures. All procedures were performed by a single surgeon (J.M.) and included 38 males (49%) and 39 females (51%). Median age was 59 and the majority of patients were ASA class III. There were 24 conversions, which decreased in frequency from 2009 (7) to 2011 (3). Reasons for conversion included significant obesity and technical difficulty. Patients with conversions had more intraoperative blood loss (966 vs 176 ml), more frequently received transfusion (29% vs 2%) and were more likely to have postoperative intensive care. Overall length of stay was longer following conversion (8.3 vs 5.6 days)., Conclusions: Robotic-assisted hepatobiliary and pancreatic procedures are often extremely complex, with a significant learning curve. Recognizing factors that prohibit successful completion of a robotic-assisted surgical procedure is key for patient safety. Careful patient selection in the appropriate settings facilitates the maximal benefit of robotic-assisted complex HPB surgery., (Copyright © 2013 John Wiley & Sons, Ltd.)

Background and Objectives: MUC1 is over-expressed and aberrantly glycosylated in >60% of human pancreatic cancer (PC). Development of novel approaches for detection and/or targeting of MUC1 are critically needed and should be able to detect MUC1 on PC cells (including cancer stem cells) and in serum., Methods: The sensitivity and specificity of the anti-MUC1 antibody, TAB 004, was determined. CSCs were assessed for MUC1 expression using TAB 004-FITC on in vitro PC cell lines, and on lineage(-) cells from in vivo tumors and human samples. Serum was assessed for shed MUC1 via the TAB 004 EIA., Results: In vitro and in vivo, TAB 004 detected MUC1 on >95% of CSCs. Approximately, 80% of CSCs in patients displayed MUC1 expression as detected by TAB 004. Shed MUC1 was detected serum in mice with HPAF-II (MUC1(high) ) but not BxPC3 tumors (MUC1(low)). The TAB 004 EIA was able to accurately detect stage progression in PC patients., Conclusions: The TAB 004 antibody may be explored as a therapeutic targeting agent for CSCs in PC. The TAB 004 EIA detected circulating MUC1 in a stage-dependent manner in patients with PC and thus may be explored as a PC stage diagnostic biomarker., (Copyright © 2013 Wiley Periodicals, Inc.)

Purpose. Operative efficiency improvements for laparoscopic ventral hernia repair (LVHR) have focused on reducing operative time while maintaining overall repair efficacy. Our objective was to evaluate procedure time and positioning accuracy of an inflatable mesh positioning device (Echo PS Positioning System), as compared to a standard transfascial suture technique, using a porcine model of simulated LVHR. Methods. The study population consisted of seventeen general surgeons (n = 17) that performed simulated LVHR on seventeen (n = 17) female Yorkshire pigs using two implantation techniques: (1) Ventralight ST Mesh + Echo PS Positioning System (Echo PS) and (2) Ventralight ST Mesh + transfascial sutures (TSs). Procedure time and mesh centering accuracy overtop of a simulated surgical defect were evaluated. Results. Echo PS demonstrated a 38.9% reduction in the overall procedure time, as compared to TS. During mesh preparation and positioning, Echo PS demonstrated a 60.5% reduction in procedure time (P < 0.0001). Although a trend toward improved centering accuracy was observed for Echo PS (16.2%), this was not significantly different than TS. Conclusions. Echo PS demonstrated a significant reduction in overall simulated LVHR procedure time, particularly during mesh preparation/positioning. These operative time savings may translate into reduced operating room costs and improved surgeon/operating room efficiency.

Background: Treatment of hepatocellular carcinoma (HCC) in the setting of cirrhosis is limited by tumor size/location and underlying liver disease. Radiofrequency ablation is utilized in selected patients; however, local recurrence remains a concern. Microwave ablation (MWA) delivers energy to tissue in a unique fashion, reducing local recurrence. A minimally invasive operative approach allows for mobilization/protection of adjacent structures, intra-operative ultrasound, and assessment of ablation progress., Study Design: Retrospective review of operative MWA performed for HCC in patients with cirrhosis over a 4-year period at a single center. Complications were stratified by Clavien-Dindo classification. Incomplete ablation and local, regional, and metastatic recurrence was assessed on follow-up imaging. Survival was assessed in months., Results: Fifty-four patients with 73 tumors underwent MWA. Median tumor size was 2.6 cm (range 0.5-8.5 cm). Cirrhosis was present in 92.6 % of patients, with a Child-Pugh score of B/C in 27.8 % and hepatitis C present in 59.3 %. A minimally invasive approach was used in 94.5 % of patients. There were no deaths within 30 days. Thirty-day morbidity was 28.9 %, with grade III complications present in 11.5 %. Delayed complications occurred in 7.8 % of patients, with a 5.6 % 90-day mortality. Incomplete ablation was identified in 5.9 % of tumors with local recurrence of 2.9 % at 9 months median follow-up. Regional and metastatic recurrence occurred in 27.5 and 11.8 % at 9 months median follow-up. Median survival was not reached at 11 months median follow-up. One- and 2-year survival was 72.3 and 58.8 %., Conclusion: Operative, preferably minimally invasive, MWA can be performed in cirrhotic patients with HCC with acceptable morbidity and low recurrence rates. High regional and metastatic recurrence rates in these patients underscore the need for minimally invasive, low morbidity approaches to liver-directed therapy.

Background: Hepatocellular carcinoma (HCC) is a rapidly increasing cancer whose known risk factors are chronic ethanol abuse, viral hepatitis infection, and aflatoxin exposure. Obesity, an emerging HCC risk factor, is reaching epidemic proportions in developed nations. This study investigated the effects of diet-induced obesity (DIO) and chronic ethanol consumption on HCC progression in mice in vivo., Methods: In this study, C57BL/6 DIO mice and lean litter mates were maintained on a 60% (high-fat diet [HFD]) diet or a 10% (control diet [CD]) kcal% fat diet for 7 weeks before they were weaned to 10/20% ([v/v], alternating days) ethanol in drinking water (EtOH) or maintenance on drinking water (H(2)O) alone. Hepatic tumor formation was initiated by intrahepatic Hepa1-6 cell (6 × 10(6) cells) inoculation 6 weeks later via the mesenteric vein., Results: The animals receiving the HFD showed decreased tumor incidence and area of hepatic foci versus the CD animals maintained on H(2)O alone. The action of EtOH suppressed tumor incidence further in both the CD and the HFD mice. Serologic analysis showed no significant differences in liver enzymes among the groups. Protein analysis demonstrated increased P450 2E1 (CYP2E1) in the groups maintained on EtOH, an effect exacerbated by HFD. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated increased tumor necrosis factor-alpha (TNF-α) expression in HFD HCC mice (H(2)O and EtOH) concomitant with decreased transforming growth factor-beta (TGF-β) expression., Conclusions: Although obesity and EtOH consumption are known risk factors for HCC initiation and development, the data in this study suggest that these factors impair progression of established tumors within the liver.

Objectives: Biliary mucinous cystic neoplasms (BMCNs) are recently redefined rare liver tumours in which insufficient recognition frequently leads to an incorrect initial or delayed diagnosis. A concise review of the subtle, sometimes non-specific, clinical, serologic and radiographic features will allow for a heightened awareness and more comprehensive understanding of these entities., Methods: Literature relating to the presentation, diagnosis, treatment, pathology and outcomes of BMCNs and published prior to March 2012 was reviewed., Results: Biliary mucinous cystic neoplasms most commonly occur in females (≥60%) in the fifth decade of life. Clinical symptoms, serologic markers and imaging modalities are unreliable for diagnosis of BMCNs, which leads to misdiagnosis in 55-100% of patients. Perioperative cyst aspiration is not recommended as invasive BMCNs can only be differentiated from non-invasive BMCNs by microscopic evaluation for the presence of ovarian-type stroma. Intraoperative biopsy and frozen section(s) are essential to differentiate BMCNs from other cystic liver lesions. The treatment of choice is complete excision and can result in excellent survival with initial correct diagnosis., Conclusions: A low threshold for considering BMCN in the differential diagnosis of cystic liver lesions and increased attentiveness to its subtle diagnostic characteristics are imperative. The complete surgical resection of BMCNs and the use of appropriate nomenclature are necessary to improve outcomes and accurately define prognosis., (© 2012 International Hepato-Pancreato-Biliary Association.)

Introduction: Pyogenic hepatic abscess induced by foreign body perforation of the gastrointestinal tract is an increasing phenomenon. Pyogenic liver abscess in itself is a challenge to treat without the complication of a foreign body., Methods: A case of a patient who developed a pyogenic hepatic abscess after unknown ingestion of a toothpick that subsequently perforated the duodenum is presented, and a literature review of pyogenic hepatic abscesses secondary to ingestion of foreign bodies and their causes, diagnosis, and treatment was performed., Discussion: Even with a thorough workup, often the diagnosis of a pyogenic hepatic abscess secondary to an endolumenal foreign body perforation is not obtained until the time of operation.

Case Presentation: A 28-year-old woman presented with dyspnea on exertion and elevated testosterone level. A 21 × 19 cm right adrenal mass was found invading the liver and inferior vena cava (IVC); tumor thrombus extended to the right atrium on transthoracic echocardiogram., Operative Procedure: Median sternotomy and extended right subcostal incisions were made. Inferior surface of liver was mobilized and vessels to the tumor divided and packed. The IVC was isolated and cardiopulmonary bypass initiated. Tumor was excised from IVC and tumor thrombus extracted. After partial IVC wall resection, the venotomy was closed. The right atrium was explored for remaining thrombus. Segment 7 of the liver was resected with division of right hepatic vein. The patient was removed from bypass, and the cut surface of liver was reinforced with chromic sutures. Intraoperative ultrasound demonstrated no remaining tumor thrombus. Provisional closure was achieved with wound vac, and the next day, the patient's wound was closed primarily., Outcome: On postoperative day 3, the patient was extubated; she was discharged on day 12. Pathology revealed well-differentiated adenocarcinoma weighing 2.3 kg with negative surgical margins. Two months after surgery, she received radiation for suspected lumbar vertebral metastasis and initiated mitotane therapy. Follow-up surveillance scans showed no evidence of disease., Discussion: Adrenocortical carcinoma is a rare malignancy presenting frequently in advanced stage with poor prognosis. Chemotherapy is often only moderately effective, while complete surgical resection is potentially curative. In this patient, excellent short-term outcome was achieved through radical surgical resection. We continue to monitor her closely for evidence of recurrence.

Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery.

Hepatocellular carcinoma (HCC) is one of the leading causes of mortality from solid organ malignancy worldwide. Because of the complexity of proteins within liver cells and tissues, the discovery of therapeutic targets of HCC has been difficult. To investigate strategies for decreasing the complexity of tissue samples for detecting meaningful protein mediators of HCC, we employed subcellular fractionation combined with 1D-gel electrophoresis and liquid chromatography-tandem mass spectrometry analysis. Moreover, we utilized a statistical method, namely, the Power Law Global Error Model (PLGEM), to distinguish differentially expressed proteins in a duplicate proteomic data set. Mass spectrometric analysis identified 3045 proteins in nontumor and HCC from cytosolic, membrane, nuclear, and cytoskeletal fractions. The final lists of highly differentiated proteins from the targeted fractions were searched for potentially translocated proteins in HCC from soluble compartments to the nuclear or cytoskeletal compartments. This analysis refined our targets of interest to include 21 potential targets of HCC from these fractions. Furthermore, we validated the potential molecular targets of HCC, MATR3, LETM1, ILF2, and IQGAP2 by Western blotting, immunohistochemisty, and immunofluorescent microscopy. Here we demonstrate an efficient strategy of subcellular tissue proteomics toward molecular target discovery of one of the most complicated human disease, HCC.

Guanine nucleotide regulatory proteins (G-proteins) are central to normal hepatocyte function and are implicated in hepatic disease initiation and progression. Regulators of G-protein signaling (RGS) are critical to defining G-protein-dependent signal fidelity, yet the role of RGS proteins in the liver is poorly defined. The aims of this study were to determine RGS17 expression in normal and transformed hepatic tissue and cells, and address the function of RGS17 in hepatic tumorgenicity. RGS17 expression was determined in human and rat HCC tissue and cell lines. Molecular approaches were used to alter RGS17 expression in HCC cells, effects on cell function measured, and RGS17 association with specific Gα-subunits determined. Using these approaches RGS17 mRNA, but not protein, was detectable in human and rat HCC tissue and cells. Conversely, RGS17 mRNA was not detected in normal tissue, isolated hepatocytes, or non-tumorigenic hepatic cells. Subsequent studies using transfected cells demonstrated that RGS17 proteins were not post-translationally modified in HCC cells, and RGS17 expression is governed by protein degradation and not via miRNAs. Notwithstanding inherently low RGS17 protein levels, altering RGS17 expression profoundly affected HCC cell mitogenesis and migration. Analysis of RGS17-G-protein interaction demonstrated RGS17 associates with both Giα- and Gqα-subunits in HCC cells of human and rat origin. In conclusion, these data demonstrate that, despite difficulties in measuring endogenous RGS protein expression, RGS17 is differentially expressed in HCC and plays a central role in regulating transformed hepatocyte tumorgenicity., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Purpose: Laparoscopic ventral hernia repair is commonly performed with mesh prostheses; however, there is no standard for fixation devices used to secure mesh to the abdominal wall. This study is a functional comparison of novel, screw-type absorbable and permanent fixation devices with a traditional titanium fixation device., Methods: Fifteen pigs each underwent the laparoscopic placement of two 11 × 14-cm mesh prostheses and were randomized for mesh fixation with either titanium spiral tacks (TS), absorbable screw-type fasteners (SF), or permanent screw-type fasteners (PF) (n = 10 mesh prostheses for each fixation group). Adhesions were assessed laparoscopically at 4 weeks. The fixation devices were also embedded in porcine abdominal rectus muscle for ex vivo mechanical testing along with partial thickness polypropylene suture (PR) as a control group (n = 40 for each group). Maximum pull-off forces were measured. All statistical tests were two-tailed, and a P-value < 0.05 was considered to be significant., Results: The mean tenacity adhesion scores were 1.40 ± 0.52 (PF), 1.7 ± 0.82 (SF), and 2.6 ± 1.07 (TS). Adhesions in the PF group were significantly less tenacious compared with the TS group (P = 0.01). Quantitative adhesion scores were not significantly different among groups. The maximum pull-off forces, measured in Newtons, were 28.61 N ± 4.89 N (TS), 22.71 N ± 7.86 N (SF), 16.98 N ± 7.59 N (PF), and 20.83 N ± 6.25 N (PR). The pull-off force in the TS group was higher than all of the other groups (P < 0.001). The SF group also had a higher pull-off force compared with the PF group (P < 0.001)., Conclusions: The screw-type absorbable and permanent fixation devices provided adequate fixation and were associated with decreased adhesions in this porcine model.

Background: Student observation of surgical procedures is standard practice performed at the discretion of the attending surgeon and the participating medical facility. The goal of our study was to evaluate patient, physician, and operating room (OR) staff opinions concerning student observation of surgical procedures at different levels of academic training., Materials and Methods: Following Institutional Review Board approval, patients undergoing elective surgery were consented to participate in the survey. An anonymous online survey was sent to attending surgeons and OR staff., Results: The majority of patients (97), physicians (91), and OR staff (71) believe that OR observational experience is important to medical student training. Patients (92%) and OR staff (97%) more so than physicians (72%) rated OR observational experience as important for nursing student education (P < 0.001). Comparatively, all groups believe this experience is less important for college and high school students (P < 0.01). When asked if patients should be informed preoperatively of student-observer presence during procedures, more patients and OR staff replied affirmatively compared with physicians (P < 0.001). Similarly, patients and OR staff more frequently believed that informed consent for OR student-observers was necessary (P < 0.0001)., Conclusion: All groups acknowledged the educational value of student observational experience, although significant disparity was noted relative to academic level and the group responding. Additionally, opinions of the OR staff were more closely aligned with those of patients. Further assessment of the role of informed consent for student-observer OR presence and potential implications is needed., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Microwave ablation (MWA) is increasingly utilized in the treatment of hepatic tumours. Promising single-centre reports have demonstrated its safety and efficacy, but this modality has not been studied in a prospective, multicentre study., Methods: Eighteen international centres recorded operative and perioperative data for patients undergoing MWA for tumours of any origin in a voluntary Internet-based database. All patients underwent operative MWA using a 2.45-GHz generator with a 5-mm antenna., Results: Of the 140 patients, 114 (81.4%) were treated with MWA alone and 26 (18.6%) were treated with MWA combined with resection. Multiple tumours were treated with MWA in 40.0% of patients. A total of 299 tumours were treated in these 140 patients. The median size of ablated lesions was 2.5 cm (range: 0.5-9.5 cm). Tumours were treated with a median of one application (range: 1-6 applications) for a median of 4 min (range: 0.5-30.0 min). A power setting of 100 W was used in 78.9% of cases. Major morbidity was 8.3% and in-hospital mortality was 1.9%., Conclusions: These multi-institution data demonstrate rapid ablation time and low morbidity and mortality rates in patients undergoing operative MWA with a high rate of multiple ablations and concomitant hepatic resection. Longterm follow-up will be required to determine the efficacy of MWA relative to other forms of ablative therapy., (© 2011 International Hepato-Pancreato-Biliary Association.)

Background: Bipolar electrosurgical devices are used to generate rapid and efficient hemostasis in a wide range of surgical procedures. Of the factors that influence seal integrity, vessel (artery) diameter has been considered the most important variable. In this study we hypothesized that the relative ratio of the components that form the seal (collagen and elastin) determine the degree of vessel distensibility and play an equally important role in defining seal strength., Methods: Porcine carotid, renal, iliac, and femoral arteries were sealed using a bipolar electrosurgical device in vivo. Following removal, arterial diameter was measured and vessels' seals tested for arterial burst pressure (ABPr). Samples were then analyzed histologically and biochemically for collagen and elastin content., Results: Arteries with the highest collagen-elastin ratio (C/E) (renal) consistently demonstrated significantly higher burst pressures than those arteries with lower C/E ratios (iliac and femoral) independent of artery diameter., Conclusion: Using arteries of distinct anatomical origin and physiological function, we demonstrate that total collagen content, and more specifically C/E ratio, in porcine arteries is a more accurate predictor of ABPr than vessel size alone.

Introduction: Composite mesh prostheses incorporate the properties of multiple materials for ventral hernia repair. This study evaluated a polypropylene/ePTFE composite mesh with a novel internal polydioxanone (PDO) absorbable ring., Methods: Composite mesh was placed intraperitoneally in 16 pigs through an open laparotomy and explanted at 2, 4, 8, and 12 weeks. Intraabdominal adhesions were measured laparoscopically. Host tissue in-growth was assessed histologically and tensiometrically. Degradation of the internal PDO ring component was also measured tensiometrically. Appropriate statistical tests were used, and P ≤.05 indicated significance., Results: No adhesions were formed in 50% of the grafts explanted at 8 weeks and 25% of grafts explanted at 12 weeks. There were significantly more vascular structures at 8 weeks, 73.5 ± 28, compared with 2 weeks, 6.75 ± 2 (P ≤.01). The T-peel force at the mesh-host tissue interface was not significantly different among time points. The absorbable PDO ring underwent complete degradation by 12 weeks., Conclusions: This composite mesh was associated with minimal intraabdominal adhesions, progressive in-growth of host tissues, and complete degradation of a novel internal PDO ring that aided mesh positioning. This composite hernia mesh showed a favorable performance in a porcine model of open ventral hernia repair.

Pancreatic resection can be performed safely in the community-based hospital setting only when appropriate systems are in place for patient selection and preoperative, operative, and postoperative care. Pancreatic surgery cannot be performed optimally without considerable investment in, and coordination of, multiple departments. Delivery of high-quality pancreatic cancer care demands a rigorous assessment of the hospital structure and the processes through which this care is delivered; however, when a hospital makes the considerable effort to establish the necessary systems required for delivery of quality pancreatic cancer care, the community and hospital will benefit substantially., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Primary liver tumors are a common clinical problem in the United States and worldwide. Resection has historically been used to treat liver lesions. Commonly used liver-directed therapies include transarterial chemoembolization, selective internal radiation therapy, and ablative therapy. Only ablative therapy can cause direct destruction of the targeted tissue. The commercially available modalities in the United States are all based on thermoablative technology. This article examines the various ablative technologies and their application, as well as how these procedures can be performed safely and with optimal outcomes, in a community cancer center., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Introduction: Microwave ablation (MWA) uses non-ionising thermal energy to cause cell death by coagulative necrosis. Colour Doppler ultrasound (US) produces a spherical image during tissue ablation that appears to approximate the microwave near field (MNF) in shape and size. The aim of the present study was to determine whether colour Doppler US images observed during microwave ablation correlate with the actual thermocoagulation zone (TCZ) observed in liver tissue., Methods: Twenty MWAs were performed in ex vivo bovine liver using a 915-MHz ablation antenna set to 45 W for 6 min concomitant with Doppler US imaging. The edges of spherical images observed with colour Doppler US were marked circumferentially in the tissue. The tissue was transected parallel to the angle of antenna insertion, and the distances between methylene blue markings and the TCZ were measured., Results: The images observed using colour Doppler US were similar in size and shape to the actual TCZ observed in the tissue. The mean distance between the observed colour Doppler US field diameter and the measured TCZ was 2 ± 1 mm., Conclusions: Using colour Doppler US, the visualised field during MWA correlates with the TCZ in an ex vivo bovine liver model. Real-time, dynamic feedback of the treatment area may increase the effectiveness of MWA for liver tumours in vivo., (© 2011 International Hepato-Pancreato-Biliary Association.)

Objectives: Obesity is a significant risk factor for many liver diseases, including hepatocellular carcinoma (HCC). Leptin has been identified as a central mediator of factors that regulate energy intake and expenditure, including appetite, metabolism and fat storage. The role of leptin in the initiation, development and progression of HCC remains poorly understood. The aims of this study were to determine the effect(s) of leptin on HCC cell proliferation and to identify potential signalling mechanism(s) by which leptin exerts these effects., Methods: Rat H4IIE HCC cells and H4IIE-derived HCC tumours were analysed for leptin receptor (LR) expression. H4IIE cells were treated with leptin (0-100 ng/ml) in the absence or presence of pharmacological inhibitors of p42/p44 mitogen-activated protein kinase (MAPK) (PD98059), p38-MAPK (SB202190) or Janus kinase-signal transducers and activators of transcription (JAK-STAT) (AG490; 10 µM) signalling. Cell proliferation was determined and signal pathway activity analysed., Results: Immunohistochemistry identified increased LR expression in HCC in human tissue. Leptin did not significantly affect H4IIE cell numbers in serum-depleted (0.1% [v/v] foetal bovine serum [FBS]) medium. However, leptin significantly inhibited serum-stimulated (1.0% [v/v] FBS) H4IIE proliferation. Immunoblot analysis demonstrated that leptin significantly activated p42/p44-MAPK, p38-MAPK and STAT3 signalling in a time-dependent manner. Pretreatment of H4IIE cells with SB202190 abrogated leptin-dependent inhibition of H4IIE proliferation, an effect not observed in cells pretreated with PD98059 or AG490., Conclusions: Leptin inhibits HCC cell growth in vitro via a p38-MAPK-dependent signalling pathway. Identifying similar effects on tumour growth in vivo may provide an attractive therapeutic target for slowing HCC progression., (© 2011 International Hepato-Pancreato-Biliary Association.)

Objectives: This study aimed to evaluate a novel three-dimensional ultrasound (US) guidance system for use in hepatic microwave ablation (MWA)., Methods: An in vitro assessment was performed in which users with different degrees of experience were evaluated for accuracy in targeting phantom lesions embedded in agar using US alone, or US in conjunction with the InVision™ System (IVS). An eight-patient pilot trial of the IVS was then performed in the setting of open hepatic MWA, in which lesions would otherwise have been targeted with conventional US., Results: In vitro studies demonstrated that the IVS significantly improved targeting accuracy at all levels of operator experience (novice, beginner and expert). In the human trial, a total of 31 tumours were targeted and all lesions were hit in one pass, as assessed by independent US image observations. There were no adverse operative events; however, there was minor line-of-sight interference with the infra-red tracking mechanism when some lesions high on the dome of the liver were targeted., Conclusions: The IVS significantly increased the accuracy of complex targeting procedures of phantom lesions and enhanced targeting in an eight-patient clinical pilot study. During the accrual phase of this pilot study, the development of improved non-optical tracking hardware obviated the requirement to maintain a direct line of sight. The trial was then halted prematurely in order to focus on the application of the IVS utilizing this non-optical modality., (© 2011 International Hepato-Pancreato-Biliary Association.)

Pancreatic cancer (PC) is a highly aggressive disease that frequently remains undetected until it has progressed to an advanced, systemic stage. Successful treatment of PC is hindered by the lack of early detection. The application of proteomic analysis to PC combined with subcellular fractionation has introduced new possibilities in the field of biomarker discovery. We utilized matched pairs of pancreas tumor and non-tumor pancreas from patients undergoing tumor resection. The tissues were treated to obtain cellular protein fractions corresponding to cytosol, membrane, nucleus and cytoskeleton. The fractions were then separated by molecular weight and digested with trypsin, followed by liquid chromatography and tandem mass spectrometry. The spectra obtained were searched using Sequest engine and combined into a single analysis file to obtain a semi-quantitative number, spectral count, using Scaffold software. We identified 2393 unique proteins in non-tumor and cancer pancreas. Utilizing PLGEM statistical analysis we determined 104 proteins were significantly changed in cancer. From these, we further validated four secreted proteins that are up-regulated in cancer and have potential for development as minimally-invasive diagnostic markers. We conclude that subcellular fractionation followed by gel electrophoresis and tandem mass spectrometry is a powerful strategy for identification of differentially expressed proteins in pancreatic cancer., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Objectives: The purpose of this study was to evaluate two electrosurgical vessel-sealing devices in biliary surgery., Methods: Porcine common bile ducts (CBDs) were sealed with two electrosurgical devices, an electrothermal bipolar vessel-sealing device (EBVS) and ultrasonic coagulation shears. Acute study animals underwent surgical bile duct sealing followed by immediate burst pressure testing. Chronic study animals were maintained for 1 week postoperatively and then tested., Results: The seal failure rate in the acute study was 50% for both the EBVS device and shears, and 0% for the laparoscopic surgical clip device used as a control. The latter had significantly higher burst pressures (646.2 ± 281.8 mmHg; P = 0.006) than the EBVS device (97.6 ± 86.6 mmHg) and shears (71.7 ± 89.3 mmHg). No significant difference in burst pressures was noted between the EBVS device and shears (97.6 ± 86.6 mmHg vs. 71.7 ± 89.3 mmHg). In the chronic study, obvious bile leaks occurred in one of four pigs (25%) in the EBVS device subgroup and two of four pigs (50%) in the shears subgroup. The average proximal CBD pressure in seven pigs was 16.1 ± 4.1 mmHg. The average chronic burst pressure in the control subgroup was 1088.0 ± 922.6 mmHg., Conclusions: Given the high rates of failure of the EBVS device and the shears in consistently sealing biliary ducts, we do not recommend their routine use in biliary surgery.

Objectives: Accurate laparoscopic liver lesion targeting for biopsy or ablation depends on the ability to merge laparoscopic and ultrasound images with proprioceptive instrument positioning, a skill that can be acquired only through extensive experience. The aim of this study was to determine whether using magnetic positional tracking to provide three-dimensional, real-time guidance improves accuracy during laparoscopic needle placement., Methods: Magnetic sensors were embedded into a needle and laparoscopic ultrasound transducer. These sensors interrupted the magnetic fields produced by an electromagnetic field generator, allowing for real-time, 3-D guidance on a stereoscopic monitor. Targets measuring 5 mm were embedded 3-5 cm deep in agar and placed inside a laparoscopic trainer box. Two novices (a college student and an intern) and two experts (hepatopancreatobiliary surgeons) targeted the lesions out of the ultrasound plane using either traditional or 3-D guidance., Results: Each subject targeted 22 lesions, 11 with traditional and 11 with the novel guidance (n= 88). Hit rates of 32% (14/44) and 100% (44/44) were observed with the traditional approach and the 3-D magnetic guidance approach, respectively. The novices were essentially unable to hit the targets using the traditional approach, but did not miss using the novel system. The hit rate of experts improved from 59% (13/22) to 100% (22/22) (P < 0.0001)., Conclusions: The novel magnetic 3-D laparoscopic ultrasound guidance results in perfect targeting of 5-mm lesions, even by surgical novices.

Background: The advancement and development of laparoscopic cholecystectomy revolutionized surgery and case management. Many procedures are routinely performed laparoscopically. Single incision laparoscopic surgery has been introduced with the hope of further reduction of scarring and possibly procedural pain. With no established technique for this procedure, the safety of single incision laparoscopic cholecystectomy has not been determined., Methods and Results: A 30-year-old man underwent single incision laparoscopic cholecystectomy for symptomatic cholelithiasis at an outside hospital. The operation was uneventful, and the patient was discharged home. The patient returned to the Emergency Department 4 days postoperatively, and a bile duct injury was diagnosed. A percutaneous drain was placed, and the patient was transferred to the Hepato-Pancreato-Biliary (HPB) service of a tertiary care center for definitive care. A delayed repair approach was used to allow the inflammation around the porta to decrease. Six weeks after injury, the patient underwent Roux-en-Y hepaticojejunostomy. The patient did well postoperatively., Conclusion: Although single incision laparoscopic surgery will play a prominent role in the future, its development and application are not without risks as demonstrated from this case. It is imperative that surgeons better define the surgical approach to achieve the critical view and select appropriate patients for single incision laparoscopic cholecystectomy.

Ablation of liver tumors is part of a multimodality liver-directed strategy in the treatment of various tumors. The goal of ablation is complete tumor destruction, and ultimately improvement of quality and quantity of life for the patient. Technology is evolving rapidly, with important improvements in efficacy. The current state of ablation technology and indications for ablation are described in this review., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background: Effectiveness of acellular human dermis (AHD) as an alternative to synthetic mesh in contaminated fields has been described. Cellular migration after implantation and corresponding strength of attachment is not well documented. Our aim is to correlate AHD vascularization, fibroblast migration, and strength of attachment with presence of inflammatory cells in clean and contaminated fields., Materials and Methods: Lewis rats were randomized to a control and three experimental groups. AHD was placed as an onlay over the intact abdominal wall. Experimental groups (n=72) were exposed to Staphylococcus aureus at 1 x 10(4), 1 x 10(5), or 1 x 10(6) by direct application; controls (n=12) were not exposed. At 5 and 28 d, abdominal walls were explanted and tissue ingrowth assessed via tensiometry measuring energy (E) and max stress (MS) at the AHD-tissue interface. Vascularity, fibroblast migration, and inflammatory cell migration were compared using light microscopy., Results: Shear strength reported as energy and max stress were significantly greater at 28 versus 5 d in all experimental groups, remaining unchanged in controls. Plasma cells and histiocytes significantly increased in all groups; macrophages increased in experimental groups only. Vascular ingrowth increased significantly in all groups; fibroblast migration was greater in controls and 1 x 10(6) exposed group only., Conclusions: Contamination of AHD results in inflammatory cell influx and a surprising increase in shear strength. Interestingly, shear strength does not increase without contamination. Inflammation stimulates vascular ingrowth, but not equally significant fibroblast migration. Longer survivals are required to determine if energy and max stress of controls increase, and fibroblast migration follows vascular ingrowth., ((c) 2010 Elsevier Inc. All rights reserved.)

The global incidence of liver cancer is greater than a million cases a year. Surgical resection where applicable is still the standard of care for these patients. Various liver-directed regional therapies have been developed in an effort to treat the vast majority of unresectable liver tumors. This article reviews the principles behind various ablation therapies currently available for malignant liver tumors and their outcomes., (Copyright 2009 Wiley-Liss, Inc.)

Composix Kugel (CK) mesh is a prosthetic available since 2000 for ventral hernia repair. A recent voluntary, class I recall of CK has caused concern regarding implantable medical devices and has caused many patients to seek medical attention and advice related to their hernia repair. Surgeons are required to answer many patient inquiries and address their concerns. Although the Food and Drug Administration (FDA) warnings can help guide surgeons in dealing with events such as this recall, detailed information and algorithms are lacking. We present information regarding the composite mesh recall and propose an algorithm for the management of patients who have had this mesh implanted.

Purpose: Microwave technology provides an emerging thermal ablation technique for solid organ tumors. We propose guidelines and recommend optimal time and power for use., Methods: Microwave ablations using a VivaWave Microwave Ablation System (Valleylab, Boulder, CO) were performed in vivo in a porcine kidney model. The independent variables were power (20, 30, 40, 45, 50, 60 W) and time (2, 4, 6, 8, 10, 15, 20 min) with the outcome variable diameter of ablation. Following ablations, kidneys were procured for gross and histological evaluation. Analysis of variance (ANOVA) was used followed by Tukey tests when appropriate. A P value of <0.05 was considered statistically significant., Results: In 308 total ablations, a minimum of 7 ablations were performed in 35 of 42 power and time variables (83%). The outcome variable, ablation diameter, was affected significantly by time, power, and time/power interaction (P < 0.0001). For each time point, a one-way ANOVA showed an overall significant difference in ablation size X wattage (P < 0.0001). Tukey tests showed that, at each time point, ablation sizes at 45, 50, and 60 W were not significantly different. After determining that 45 W was optimal, a one-way ANOVA showed an overall significant difference in ablation sizes for time points at 45 W (P < 0.0001). Tukey tests showed that, at 45 W, ablation sizes at 10 min were significantly larger than ablation sizes at 8, 6, 4, and 2 min., Conclusions: We propose guidelines for use of a novel microwave ablation system and recommend use at 45 W for 10 min.

Background: In addition to the biochemical components secreted in bile, aquaporin (AQP) water channels exist in hepatocyte membranes to form conduits for water movement between the sinusoid and the bile canaliculus. The aim of the current study was to analyse AQP 9 expression and localization in human hepatocellular carcinoma (HCC) and non-tumourigenic liver (NTL) tissue from patients undergoing hepatic resection., Methods: Archived tissue from 17 patients was sectioned and analysis performed using an antibody raised against AQP 9. Slides were blind-scored to determine AQP 9 distribution within HCC and NTL tissue., Results: Aquaporin 9 was predominantly expressed in the membranes of hepatocytes and demonstrated zonal distribution relative to hepatic sinusoid structure in normal liver. In HCC arising in the absence of cirrhosis AQP 9 remained membrane-localized with zonal distribution in the majority of NTL. By contrast, AQP 9 expression was significantly decreased in the HCC mass vs. pair-matched NTL. In HCC in the presence of cirrhosis, NTL was characterized by extensive AQP 9 staining in the membrane in the absence of zonal distribution and AQP 9 staining in NTL was significantly greater than that observed in the tumour mass., Conclusions: These data demonstrate that human HCC is characterized by altered AQP 9 expression and AQP 9 localization in the NTL mass is dependent on underlying liver pathology. Given the central role of AQPs in normal liver function and the potential role of AQPs during transformation and progression, these data may prove valuable in future diagnostic and/or therapeutic strategies.

Background: Bipolar electrosurgical devices and ultrasonic devices are routinely used in open and advanced laparoscopic surgery for hemostasis. New electrosurgical and ultrasonic instruments demonstrate improved quality and efficiency in blood vessel sealing., Methods: The 5-mm laparoscopic Gyrus PKS Cutting Forceps (PK), Gyrus Plasma Trissector (GP), Harmonic Scalpel (HS), EnSeal Tissue Sealing and Hemostasis System (RX), LigaSure V with LigaSure Vessel Sealing Generator (LS), LigaSure V with Force Triad Generator (FT), and Ligamax 5 Endoscopic Multiple Clip Applier (LM) were tested to compare burst pressure, sealing time, and failure rate. Each device was used to seal 13 small (2-3 mm diameter), 13 medium (4-5 mm diameter), and 13 large (6-7 mm diameter) arteries from euthanized pigs. A p value <0.05 was considered statistically significant., Results: Mean burst pressures were not statistically different for 2-3 mm or 6-7 mm vessels. For 4-5 mm vessels, LS had the highest mean burst pressure recorded. Mean seal times were shorter for every vessel size when FT was compared with LS (p < 0.05). The shortest sealing times for 2-3 mm vessels were recorded for GP. The shortest sealing times for medium and large vessels were observed with FT. The highest percentage failure rate for each vessel size occurred with GP. For 4-5 mm diameter vessels, the failure rate was 48% for GP, 41% for PK, and 22% for HS. For 6-7 mm diameter vessels, the failure rate was 92% for GP, 41% for PK, and 8% for HS. LM and FT had no recorded failures., Conclusion: Among the new 5-mm laparoscopic electrosurgical and ultrasonic instruments available for testing, RX, LS, and FT produced the highest mean burst pressures. FT had the shortest mean seal times for medium and large vessels. Minimal or no seal failures occurred with HS, RX, LS, LM, and FT.

Current treatment guidelines for appendiceal adenocarcinoma specify that right hemicolectomy should be performed. This study evaluates appendiceal cancer outcomes in the United States and treatment guideline compliance. Data for patients diagnosed with appendiceal adenocarcinoma in the Surveillance, Epidemiology, and End Results database (1988 to 2003) were analyzed. The 2511 patients with appendiceal adenocarcinoma had an average age of 59.3 years, average tumor size of 4.05 cm, and 5-year survival rate of 57 per cent. The 5-year survival rate by stage was statistically different (P < 0.001): Stage 0, 95.7 per cent; Stage I, 88 per cent; Stage II, 75.2 per cent; Stage III, 37.1 per cent; and Stage IV, 25.6 per cent. Appendectomy was performed in 33.4 per cent, which does not follow the current guidelines. In this group, 5-year survival was significantly less for patients with Stage III and IV disease (48% vs. 38.2%, P = 0.03; 46% vs. 26.4%, P = 0.04, respectively). Patients with Stage I and II disease had similar 5-year survival for appendectomy and colectomy (90.2% vs. 90.1%, P = 0.7; 78.3% vs. 76%, P = 0.6, respectively). One-third of patients with adenocarcinoma did not undergo current surgical guideline therapy. However, it appears hemicolectomy only improved survival for patients with later-stage disease. The current data raise the question of whether Stage I and II appendiceal cancer can be adequately treated with simple appendectomy.

Chronic groin pain is the most frequent long-term complication after inguinal hernia repair affecting up to 34 per cent of patients. Traditional surgical management includes groin exploration, mesh removal, and neurectomy. We evaluate outcomes of a combined laparoscopic and open approach to chronic pain after inguinal herniorrhaphy. All patients undergoing surgical exploration for chronic pain after inguinal herniorrhaphy were analyzed. In most, the operation consisted of mesh removal (open or laparoscopic), neurectomy, and placement of mesh in the opposite location of the first mesh (laparoscopic if the first was open and vice-versa). Main outcome measures included pain status, numbness, and hernia recurrence. Twenty-one patients (16 male and 5 female) with a mean age of 41 years (22-51 years) underwent surgical treatment for unilateral (n = 18) or bilateral (n = 3) groin pain. Percutaneous nerve block was unsuccessful in all patients. Four had previous surgery for pain. There were no complications. With a minimum of 6 weeks follow-up, 20 of 21 patients reported significant improvement or resolution of symptoms. A combined laparoscopic and open approach for postherniorrhaphy groin pain results in excellent patient satisfaction with minimal morbidity. It may be the preferred technique for the definitive management of chronic neuralgia after hernia repair.

The purpose of our study was to provide guidelines for the use of a novel microwave ablation system. Microwave ablations using a 915-MHz system were evaluated in a porcine liver. The independent variables were power and time, with the outcome variable being diameter of ablation. After ablations, livers were procured for measurement and histologic evaluation. Our study consisted of 420 ablations. The outcome variable, ablation diameter, was affected significantly by time, power, and time/power interaction (p<0.0001). For each time point, a one-way analysis of variance (ANOVA) showed an overall significant difference in ablation size X wattage (p<0.0001). Tukey tests at each time point showed ablation sizes at 45, 50, and 60 W were not significantly different. After it was determined that 45 W was optimal, a one-way ANOVA showed an overall significant difference in ablation sizes for time points at 45 W (p<0.0001). Tukey tests revealed that at 45 W, ablation sizes at 10, 15, and 20 min were not statistically different. We propose guidelines for diameters based on different time and power variables and recommend 45 W for 10 min to achieve optimal diameters at the shortest time and lowest wattage.

Many treatment strategies have been proposed for pyogenic liver abscesses; however, the indications for liver resection for treatment have not been studied in a systematic manner. The purpose of our study was to evaluate the role of surgical treatment in pyogenic abscesses and to determine an optimal treatment algorithm. We retrospectively reviewed the medical records of all patients who had a pyogenic liver abscess at Rhode Island Hospital between 1995 and 2002. Abscesses and treatment strategies were classified into three groups each. The abscess groups included Abscess Type I (small <3 cm), Abscess Type II (large >3 cm, unilocular), and Abscess Type III (large >3 cm, complex multilocular). The treatment strategy groups included Treatment Group A (antibiotics alone), Treatment Group B (percutaneous drainage plus antibiotics), and Treatment Group C (primary surgical therapy). Descriptive statistics were calculated and chi2 used for comparison with a P < 0.05 considered significant. Our study consisted of 107 patients with pyogenic liver abscess. The success rate for small abscesses treated with antibiotics was 100 per cent. The success rate with antibiotics and percutaneous drainage for large, unilocular abscesses was 83 per cent and for large, multiloculated abscesses was 33 per cent. None of the 27 patients who had surgical therapy for large, multiloculated abscesses had recurrences. Surgical treatment for large (>3 cm), multiloculated abscesses had a significantly higher success rate than percutaneous drainage plus antibiotic therapy (33% versus 100%, P < or = 0.01). The mortality rate for the percutaneous drainage plus antibiotic group was not significantly different from the primary surgical group (4.2% versus 7.4%, P = 0.40). We propose a treatment algorithm with small abscesses being treated with antibiotics alone; large, uniloculated abscess with percutaneous drainage plus antibiotics; and large, multiloculated abscessed treated with surgical therapy.

Background: Abdominal wall hernias are a frequent and formidable challenge for general surgeons. Several different surgical techniques and types of mesh prosthetics are available for repair. We evaluated outcomes of an open ventral hernia repair using a synthetic composite mesh., Study Design: We prospectively collected data on consecutive patients undergoing open ventral hernia repair using a synthetic composite mesh from January 1, 2000 to December 31, 2005 at four large medical centers. Four surgeons used a standardized surgical procedure for all patients., Results: The study consisted of 455 patients with an average age of 56 years; 54% were men. Sixty-nine percent of the patients underwent repairs for recurrent hernias. Mean defect size was 44 cm(2), and mean mesh size was 213 cm(2). Average length of hospital stay was 1.1 days. Thirty-one patients had 33 early complications (7%), and 3 patients (0.7%) required reoperation (one each for seroma, bowel injury, and wound breakdown). Early infection occurred in four patients (0.9%), and one patient required reoperation and graft removal. Late complications occurred in nine patients (2%), with two patients requiring reoperation. Late infections occurred in two patients (0.4%); both required antibiotic treatment. Recurrent hernias were observed in 6 patients (1%; 6 of 450 because of 5 patients with unknown recurrence) at a mean followup of 29.3 months., Conclusions: In this large multicenter series, open ventral hernia repair using a composite mesh resulted in a short hospital stay, moderate complication rate, low infection rate, and low recurrence rate.

Objectives: We sought to measure the strength of tissue attachment to mesh after laparoscopic ventral hernia repair in a porcine model., Methods: Twelve swine had two 10-cm x 16-cm sheets of ePTFE and polypropylene/ePTFE composite mesh fixated to the abdominal wall laparoscopically. Animals were euthanized at 2, 4, 6, and 12 weeks. The strength of tissue ingrowth was measured using a lap-shear method. Data are reported as mean force in pounds., Results: Average surface area of adhesions to percentage of surface area was not statistically significant between the composite and ePTFE materials. For the composite material, there was a 98.7% posterior probability that the force required at 2 weeks was less than that required at 12 weeks. There was no difference in graft-abdominal wall interface strength between week 2 and week 12 for ePTFE material. Both prosthetics achieved the majority of their strength from tissue ingrowth by 2 weeks, but the composite prosthesis continued to gain strength while the strength of the ePTFE plateaued. Composite mesh demonstrated a statistically significant increase in strength between the lap-shear force, whereas no statistically significant difference occurred in the ePTFE graft. For the composite material, there was complete cellular infiltration through the entire thickness of polypropylene (approximately 500 microm) to the ePTFE layer at 2 weeks. At 2 weeks for ePTFE, the cells did not penetrate into the graft on the visceral side. On the abdominal wall side, the grooves filled with tissue, but no cellular penetration into the ePTFE occurred. No histological difference existed in cellularity., Conclusion: This study demonstrates that the strength of tissue ingrowth is significantly higher (P<0.05) for the composite grafts relative to the ePTFE grafts at each time point. Approximately 74% of tissue ingrowth and strength occurs by 2 weeks postoperatively for the composite prosthesis. The ePTFE graft tissue strength peaked and plateaued by 2 weeks. This may have clinical implications for human ventral hernia repair by partly addressing the issue of graft fixation to the abdominal wall during laparoscopic ventral hernia repair.

Objective: We evaluated two new radiofrequency devices in an in vivo porcine model., Materials and Methods: Multiprobe radiofrequency ablation (RFA) was used in a porcine model with an impedance-based algorithm in one experiment and clustered probes with and without switcher controllers in another; a Pringle maneuver was used with half of the ablations., Results: The impedance experiment included 13 ablations, with a mean length of 7.0 cm and width of 2.9 cm (95% CI) and an average time of 596 s. Ablation volumes were significantly larger (54.1+/-11.7 cc(3) vs 34.9+/-4.8 cc(3), p<0.05) and ablation times were significantly shorter (359 s vs 834 s, p<0.05) for the Pringle group compared with the No Pringle group, respectively. The switcher controller experiment included 34 RFAs. Diameter (mm) (51.4 vs 40.3, p<0.0001), surface area (cm(2)) (22.4 vs 16.0, p<0.0002), and volume (cc) (66.1 vs 36.9, p<0.0001) were significantly larger for the combination probes with switcher controller compared with clustered probes, respectively. Ablation volumes for the Pringle vs No Pringle groups in the combination probes were 68.0 cc vs 64.3 cc and for the clustered probes 40.1 cc vs. 33.7 cc, respectively., Conclusion: Multiprobe ablations using RFA are promising technologies that need further study to evaluate their clinical utility.

Background: Thermal ablation techniques have become important treatment options for patients with unresectable hepatic malignancies. Microwave ablation (MWA) is a new thermal ablative technique that uses electromagnetic energy to produce coagulation necrosis. We report outcomes from the first clinical trial in the United States using MWA and a 915 MHz generator., Patients and Methods: Patients with unresectable primary or metastatic liver cancer were enrolled in a multi-institutional trial from March 2004 through May 2006. Demographic information, diagnosis, treatment, and outcomes were documented., Results: Eighty-seven patients underwent 94 ablation procedures for 224 hepatic tumors. Forty-two ablations (45%) were performed open, 7 (7%) laparoscopically, and 45 (48%) percutaneously. The average tumor size was 3.6 cm (range 0.5-9.0 cm). Single antenna ablation volumes were 10.0 ml (range 7.8-14.0 ml), and clustered antennae ablation volumes were 50.5 ml (range 21.1-146.5 ml). Outcome variables were measured with a mean follow-up of 19 months. Local recurrence at the ablation site occurred in 6 (2.7%) tumors, and regional recurrence occurred in 37 (43%) patients. With a mean follow-up of 19 months, 41 (47%) patients were alive with no evidence of disease. There were no procedure-related deaths. The overall mortality rate was 2.3%., Conclusions: Microwave ablation is a safe and effective technology for hepatic tumor ablation. In our study, clustered antennae resulted in larger ablation volumes. Further studies with histological confirmation are needed to verify clinical results.