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Abstract Background A left thoracotomy approach is anatomically appropriate for childhood aortic coarctation; however, the pediatric femoral arteriovenous diameters are too small for cardiopulmonary bypass cannulation. We aimed to determine the safety of a partial cardiopulmonary bypass through the main pulmonary artery and the descending aorta in pediatric aortic coarctation repair. Methods We retrospectively reviewed 10 patients who underwent coarctation repair under partial main pulmonary artery-to-descending aorta cardiopulmonary bypass with a left thoracotomy as the CPB group. During the same period, 16 cases of simple coarctation of the aorta repair, with end-to-end anastomosis through a left thoracotomy without partial CPB assistance, were included as the non-CPB group to evaluate the impact of partial CPB. Results The median age and weight at surgery of the CPB group were 3.1 years (range, 9 days to 17.9 years) and 14.0 (range, 2.8–40.7) kg, respectively. Indications for the partial cardiopulmonary bypass with overlap were as follows: age > 1 year (n = 7), mild aortic coarctation (n = 3), and predicted ischemic time > 30 min (n = 5). Coarctation repair using autologous tissue was performed in seven cases and graft replacement in three. The mean partial cardiopulmonary bypass time, descending aortic clamp time, and cardiopulmonary bypass flow rate were 73 ± 37 min, 57 ± 27 min, and 1.6 ± 0.2 L/min/m2, respectively. Urine output during descending aortic clamping was observed in most cases in the CPB group (mean: 9.1 ± 7.9 mL/kg/h), and the total intraoperative urine output was 3.2 ± 2.7 mL/kg/h and 1.2 ± 1.5 mL/kg/h in the CPB and non-CPB group, respectively (p = 0.020). The median ventilation time was 1 day (range, 0–15), and the intensive care unit stay duration was 4 days (range, 1–16) with no surgical deaths. No major complications, including paraplegia or recurrent coarctation, occurred postoperatively during a median observation period of 8.1 (range, 3.4–17.5) years in the CPB group. In contrast, reoperation with recurrent coarctation was observed in 2 cases in the non-CPB group (p = 0.37). Conclusions Partial cardiopulmonary bypass through the main pulmonary artery and descending aorta via a left thoracotomy is a safe and useful option for aortic coarctation repair in children.

Summary:. We present a case in which reconstruction of the dorsum of the hand and finger web space was carried out concurrently with the insertion of a superficial inferior epigastric artery flap into the interdigital spaces. This approach was taken to prevent the potential development of subsequent web space contracture. The patient, a 57-year-old woman, presented with a necrotizing soft tissue infection on the dorsum of her left hand, resulting in a full-thickness skin defect extending from the metacarpophalangeal joint to the wrist, with exposure of the extensor tendons. The reconstructive surgery involved raising a superficial inferior epigastric artery flap and transplanting it onto the tissue defect, to cover not only the dorsal defect but also the interdigital spaces after releasing web space contracture. Consequently, the surgery successfully released scar contractures on the dorsum of the hand and provided adequate interdigital space formation without requiring additional procedures, except defatting. At the 7-month postoperative follow-up, the patient had a good outcome with shoulder and hand (Quick Disabilities of Arm, Shoulder and Hand) score of 28.9 points. Interdigital scar contractures often lead to decreased fine motor skills and functional impairment, affect aesthetics, and require a prolonged period for social reintegration. This surgical technique involves simultaneous one-stage closure of the dorsal defect with a flap and interdigital reconstruction to prevent future scar contractures and functional impairments, and is a valuable approach for shortening the treatment duration.

Abstract Background Conversion surgery (CS) after chemotherapy is weakly recommended as a promising tool for improving prognoses in patients with unresectable gastric cancer. Moreover, several investigators have demonstrated the clinical efficacy of subtotal gastrectomy (sTG) with a small remnant stomach for the nutritional status and surgical outcome compared with total gastrectomy. Here, we report a patient with liver metastasis from human epidermal growth factor receptor 2 (HER2)-positive gastric cancer who underwent sTG and hepatectomy after trastuzumab-based chemotherapy. Case presentation An 84-year-old male patient was diagnosed with HER2-positive gastric cancer with a single liver metastasis. He was treated with eight courses of trastuzumab in combination with S-1 and oxaliplatin as first-line chemotherapy. The primary tumor and liver metastasis shrank significantly. The metastatic liver lesion’s reduction rate was 65%. According to the Response Evaluation Criteria in Solid Tumors, the patient had a partial response. Therefore, he underwent an sTG with D2 lymphadenectomy and partial hepatectomy of segment 2. Histopathological examination revealed a grade 3 histological response without lymph node metastases from the primary tumor. No viable cancer cells were observed in the resected liver specimens. The patient received adjuvant chemotherapy with S-1. The postoperative quality of life (QOL) evaluated using the Postgastrectomy Syndrome Assessment Scale-45 was maintained, and the patient was still alive 8 months after the CS without recurrence. Conclusions An sTG with a small remnant stomach might be clinically useful for preventing a decline in QOL and improving prognoses in patients with stage IV gastric cancer after chemotherapy.

Abstract Aim We explored institutional factors in Japan associated with lower operative mortality and failure‐to‐rescue (FTR) rates for eight major gastrointestinal procedures. Methods A 22‐item online questionnaire was sent to 2119 institutional departments (IDs) to examine the association between institutional factors and operative mortality and FTR rates. IDs were classified according to the number of annual surgeries, board certification status, and locality. In addition, the top 20% and bottom 20% of IDs were identified based on FTR rates and matched with the results of the questionnaire survey. Factors associated with operative mortality were selected by multivariate analysis. Results Of the 1083 IDs that responded to the questionnaire, 568 (213 382 patients) were included in the analysis. Operative morbidity, operative mortality, and FTR rates in the top 20% and bottom 20% of IDs were 13.1% and 8.4% (p

Abstract Background Recent advances in treatment are expected to bring a cure to more patients with gastric cancer (GC). Focusing on the risk of death from other diseases (DOD) has become a crucial issue in patients cured of GC. The aim of this study was to elucidate the risk factors for DOD in patients who underwent curative gastrectomy with lymph node dissection for GC. Methods We enrolled 810 patients who underwent curative gastrectomy with lymph node dissection for GC from January 1990 to December 2014 and had no recurrence or death of GC until December 2019. We investigated the risk factors for DOD defined as death excluding death from a malignant neoplasm, accident, or suicide after gastrectomy, focusing on the perioperative characteristics at gastrectomy. Results Among 315 deaths from any cause, 210 died from diseases other than malignancy, accidents and suicide. The leading cause of DOD was pneumonia in 54 patients (25.7%). The actual survival period in 167 patients (79.5%) with DOD was shorter than their estimated life expectancy at gastrectomy. Multivariate analysis revealed that a high Charlson Comorbidity Index score (score 1–2: hazard ratio [HR] 2.192, 95% confidence interval [CI] 1.713–2.804, P

Abstract Purpose This study aimed to examine the incidence of incisional hernia (IH) in elective laparoscopic colorectal surgery (LC) using regulated computed tomography (CT) images at intervals every 6 months. Methods We retrospectively examined the diagnosis of IH in patients who underwent LC for colorectal cancer at Kansai Medical University Hospital from January 2014 to August 2018. The diagnosis of IH was defined as loss of continuity of the fascia in the axial CT images. Results 470 patients were included in the analysis. IH was diagnosed in 47 cases at 1 year after LC. The IH size was 7.8 cm2 [1.3–55.6]. In total, 38 patients with IH underwent CT examination 6 months after LC, and 37 were already diagnosed with IH. The IH size was 4.1 cm2 [0–58.9]. The IH size increased in 17 cases between 6 months and 1 year postoperatively, and in 1 case, a new IH occurred. 47%(18/38) of them continued to grow until 1 year after LC. A multivariate analysis was performed on the risk of IH occurrence. SSI was most significantly associated with IH occurrence (OR:5.28 [2.14–13.05], p = 0.0003). Conclusion IH occurred in 10% and 7.9% at 1 year and 6 months after LC. By examining CT images taken for the postoperative surveillance of colorectal cancer, we were able to investigate the occurrence of IH in detail.

Abstract Background The current standard operation for proximal gastric and gastroesophageal junction (P/GEJ) cancers with limited esophageal extension is total gastrectomy (TG). TG is associated with impaired appetite and weight loss due to the loss of gastric functions such as production of ghrelin and with anemia due to intrinsic factor loss and vitamin B12 malabsorption. Theoretically, proximal gastrectomy (PG) can mitigate these problems by preserving gastric function. However, PG with direct esophagogastric reconstruction is associated with severe postoperative reflux, delayed gastric emptying, and poor quality of life (QoL). Minimally invasive PG (MIPG) with antireflux techniques has been increasingly performed by experts but is technically demanding owing to its complexity. Moreover, the actual advantages of MIPG over minimally invasive TG (MITG) with regards to postoperative QoL are unknown. Our overall objective of this study is to determine the short-term QoL benefits of MIPG. Our central hypotheses are that MIPG is safe and that patients have improved appetite after MIPG with effective antireflux techniques, which leads to an overall QoL improvement when compared with MITG. Methods Enrollment of a total of 60 patients in this prospective survey-collection study is expected. Procedures (MITG versus MIPG, antireflux techniques for MIPG [double-tract reconstruction versus the double-flap technique]) will be chosen based on surgeon and/or patient preference. Randomization is not considered feasible because patients often have strong preferences regarding MITG and MIPG. The primary outcome is appetite level (reported on a 0-10 scale) at 3 months after surgery. With an expected 30 patients per cohort (MITG versus MIPG), this study will have 80% power to detect a one-point difference in appetite level. Patient-reported outcomes will be longitudinally collected (including questions about appetite and reflux), and specific QoL items, body weight, body mass index and ghrelin, albumin, and hemoglobin levels will be compared. Discussion Surgeons from the US, Japan, and South Korea formed this collaboration with the agreement that the surgical approach to P/GEJ cancers is an internationally important but controversial topic that requires immediate action. At the completion of the proposed research, our expected outcome is the establishment of the benefit and safety of MIPG. Trial registration This trial was registered with Clinical Trials Reporting Program Registration under the registration number NCI-2022–00267 on January 11, 2022, as well as with ClinicalTrials.gov under the registration number NCT05205343 on January 11, 2022.

Abstract Purpose The aim of this study was to compare the clinical characteristics of ulcerative colitis (UC) patients who underwent surgery for cancer/dysplasia with those who underwent surgery for refractory disease and to discuss the preoperative preparation for successful hand-sewn IPAA. Methods Patients who underwent surgery for UC between January 2014 and December 2021 at Hyogo Medical University were included in the study. A total of 443 UC surgical cases were included in the study, which comprised 188 cancer/dysplasia patients and 255 refractory patients. Clinical records were compared retrospectively. Results The proportion of surgical UC cases with cancer/dysplasia has been on the rise, accounting for approximately 40% in recent years. The duration of disease (months) was 186 (2–590) in the cancer/dysplasia group and 48 (1–580) in the refractory group (p = 0.02). UC severity (mild/moderate/severe) was 119/69/0 in the cancer/dysplasia group and 18/157/80 in the refractory group (p

Objective:. To determine the magnitude of the perioperative costs associated with robotic gastrectomy (RG). Background:. A robotic surgery platform has a high implementation cost and requires maintenance costs; however, whether the overall cost of RG, including all perioperative costs, is higher than conventional open gastrectomy (OG) remains unknown. Methods:. Patients who underwent a major gastrectomy during February 2018 through December 2021 were retrospectively identified. We calculated the perioperative costs of RG and OG and compared them overall as well as in different phases, including intraoperative costs and 30-day postsurgery inpatient and outpatient costs. We investigated factors potentially associated with high cost and estimated the likelihood of RG to reduce overall cost under a Bayesian framework. All cost data were converted to ratios to the average cost of all operations performed at our center in year FY2021. Results:. We identified 119 patients who underwent gastrectomy. The incidence of postoperative complications (Clavien-Dindo >IIIa; RG, 10% vs OG, 13%) did not significantly differ between approaches. The median length of stay was 3 days shorter for RG versus OG (4 vs 7 days, P < 0.001). Intraoperative cost ratios were significantly higher for RG (RG, 2.6 vs OG, 1.7; P < 0.001). However, postoperative hospitalization cost ratios were significantly lower for RG (RG, 2.8 vs OG, 3.9; P < 0.001). Total perioperative cost ratios were similar between groups (RG, 6.1 vs OG, 6.4; P = 0.534). The multiple Bayesian generalized linear analysis showed RG had 76.5% posterior probability of overall perioperative cost reduction (adjusted risk ratio of 0.95; 95% credible interval, 0.85–1.07). Conclusions:. Despite increased intraoperative costs, total perioperative costs in the RG group were similar to those in the OG group because of reduced postoperative hospitalization costs.

Abstract Aim The purpose of this study was to examine how the clinical characteristics, indications for surgery, and postoperative course of ulcerative colitis (UC) surgical patients changed before and after the introduction of biological agents. Methods Patients who underwent surgery for UC at Hyogo Medical University between 2000 and 2019 were included in the study; those who underwent surgery between 2000 and 2009 were included in the early group (n = 864), and those who underwent surgery between 2010 and 2019 were included in the late group (n = 834); each study factor was retrospectively compared. Results The mean ages at surgery (y) were 39.7 ± 15.1 y in the early group and 46.7 ± 17.8 y in the late group (P

Abstract Background Preoperative treatment is performed for locally advanced colon cancer with extensive tumor proximity or suspected invasion of skeletal muscles, major organs, and blood vessels. Oxaliplatin-based regimens are often used in preoperative chemotherapy. However, microsatellite instability (MSI)-high colorectal cancer is often resistant to cytotoxic anticancer agents. Herein, we describe a case of treatment of anticancer drug-resistant MSI-high locally advanced colon cancer and review cases of complete response to immune checkpoint inhibitor therapy for colorectal cancer. Case presentation A 57-year-old woman was referred to our hospital with a large tumor in the descending colon and extensive thoracic and abdominal wall involvement, including the ribs and diaphragm. No distant metastasis was observed. The tumor had perforated the abdominal wall and formed an abscess. Upon visiting our hospital, emergency surgery was performed. An abdominal wall incision was made to drain the abscess and laparoscopic colostomy was performed. Histopathological examination of biopsy specimens revealed an adenocarcinoma with positive immunohistochemical expressions of both CDX2 and CK20. The patient was diagnosed with a descending colon cancer. Genetic examination found MSI-high, Kras mutation (F12G), and wild-type BRAF. After the inflammation improved, chemotherapy with the FOLFIRI regimen was initiated, but the tumor grew rapidly. As a second-line treatment, nivolumab and ipilimumab combination therapy was initiated. After four cycles of these therapies, the patient was administered nivolumab alone for five cycles. Tumor shrinkage was observed and radical surgery was performed. The patient underwent laparoscopic descending colon and partial thoracic and abdominal wall resection. The abdominal wall muscle was dissected from the abdominal cavity, and subcutaneous tissues, diaphragm, ribs were dissected from the body surface. Pathological examination revealed mucus components, fibrous tissues, and no malignant cells, indicating a complete pathological response (pCR). The patient had a good postoperative course and returned to work after being discharged. No recurrence was observed six months postoperatively. Conclusions Herein, we report a case of anticancer drug-resistant MSI-high colon cancer that was resected after treatment with immune checkpoint inhibitors, and a pCR was achieved. This new treatment strategy can be used for the treatment of cases that are not responsive to conventional therapies.

Abstract Background Colorectal carcinoma with enteroblastic differentiation is a rare subtype of colorectal carcinomas expressing at least one characteristic immunohistochemical marker among α-fetoprotein, glypican-3, and spalt-like transcription factor 4. On the other hand, colorectal carcinoma with neuroendocrine differentiation is also a unique subtype of colorectal carcinomas showing expression of at least one distinctive marker among chromogranin A, synaptophysin, and CD56. Case presentation We experienced an extremely rare case of rectal carcinoma with dual differentiation toward enteroblastic and neuroendocrine features in a 53-year-old male patient with long-standing ulcerative colitis (UC). Most of the tumor cells were positive for enteroblastic differentiation markers and approximately a half of them for neuroendocrine differentiation markers. Some tumor cells showed only enteroblastic differentiation, and some did only neuroendocrine feature, but some showed both enteroblastic and neuroendocrine differentiation. Conclusion Colorectal carcinoma with dual differentiation toward enteroblastic and neuroendocrine features has not been reported yet. Neoplastic transformation from pluripotent stem cells in dysplastic epithelium of long-standing UC patients may be associated with such dual differentiation features.

Purpose: Type IIIb endoleak is a complication of endovascular repair of abdominal aortic aneurysms. The frequency of a type Ⅲb endoleak is approximately 0.23%. Because of its rarity, it poses diagnostic and treatment challenges. Case Report: A 72-year-old man underwent endovascular repair of an abdominal aortic aneurysm with an AFX with DuraPly™ (Endologix LLC, Irvine, CA, USA). One year later, he developed a type IIIb endoleak with rapid re-expansion of the aortic aneurysm due to stent fracture of main body of AFX. He then underwent a second AFX endovascular repair; however, one month after, follow-up ultrasonography showed blood flowing into the abdominal aortic aneurysm from the site of the previous type IIIb endoleak. A third endovascular repair was performed using an Excluder® (W. L. Gore & Associates, Newark, DE, USA); fortunately, during the six-month follow-up, the endoleak did not recur and the diameter of the aneurysm did not enlarge. Conclusion: Type IIIb endoleak is a very rare complication of endovascular aortic aneurysm repair and can be difficult to treat. However, it is essential to ensure that the proximal and distal seal zones are adequate, fixation is secure, and the components sufficiently overlap.

Abstract Background The incidence of ulcerative colitis (UC) is increasing, but there are few reports comparing elderly UC patients undergoing colectomy for elderly-onset UC (EO) and nonelderly-onset UC (NEO). The aim of this study was to analyze the differences between EO and NEO patients who underwent UC-related surgery. Methods We identified 1973 patients with UC who underwent colectomy at Hyogo College of Medicine between January 1, 1984, and December 31, 2018. Only patients aged 65 years old and older who underwent colectomy were enrolled in this study (n = 221, 11.2%), and their clinical records were retrospectively reviewed. Patients were divided into two groups according to their age at disease onset: those with onset at younger than 60 years old (NEO) and at 60 years old or older (EO). Results In the 221 UC patients who underwent colectomy at 65 years old or older, there were 155 cases of EO and 66 cases of NEO. The main surgical indication in NEO patients was colitis-associated cancer/dysplasia (32/66, 47%). In contrast, refractory to medical treatment was the leading cause of surgery in EO patients (80/155, 52%). The distributions of surgical indications were different between the two groups (p

Abstract Background Acquired jejunal diverticula are relatively rare conditions. While mostly asymptomatic, they can occasionally cause life-threatening complications requiring surgical treatment. We herein report a case of hemorrhagic shock due to jejunal diverticulum with intestinal amyloidosis that was successfully managed via transcatheter arterial embolization (TAE) and surgery. Case presentation An 80-year-old female presenting with hematochezia and hemorrhagic shock was transferred to our institution. Contrast-enhanced computed tomography revealed extravasation in the small bowel around the upper jejunum. Massive transfusion was performed with subsequently planning for TAE to control bleeding followed by surgical laparotomy to evaluate the ischemic intestine. First, the second jejunal artery was selectively embolized with a 1:3 mixture of N-butyl cyanoacrylate (NBCA) and iodize oil, after which laparotomy was performed. Multiple jejunal diverticula were detected near Treitz’ ligament, and an induration of NBCA was palpable in the nearby mesentery. The intraoperative diagnosis was massive bleeding from acquired jejunal diverticula for which jejunectomy including the nearby diverticulum was performed to prevent future bleeding. Her postoperative course was stable. Histological examination of the specimen revealed several false diverticula with intestinal amyloidosis. Conclusion Hemorrhagic shock due to jejunal diverticulum with intestinal amyloidosis is extremely rare. Combined treatment of TAE and surgical laparotomy appears to be effective, because the bleeding point can be identified by palpation of the embolic material.

Introduction: Due to the narrow portal of entry, microendoscopic laminectomy (MEL) is associated with a risk of postoperative spinal epidural hematoma (POSEH). This risk might be higher when performing multiple-level (m-) MEL. The purpose of this study is to clarify the incidence rate of POSEH following single-level (s-) and m-MEL by each interlaminar level and identify the risk factors for POSEH following m-MEL. Methods: A total of 379 patients underwent MEL of the lumbar spine (s-MEL, n=141; m-MEL, n=238). We determined the incidence of POSEH following s-MEL and m-MEL by each interlaminar level. For m-MEL, we clarified the correlation between POSEH and possible risk factors, such as operative findings, the sequence of operated interlaminar levels, and the preoperative cross-sectional dural area (CSA) on magnetic resonance imaging. Results: The incidence rate at L2/3 was significantly higher than that at L3/4 and L4/5. Patients who underwent L2/3 decompression at the end of the procedure showed a higher incidence of POSEH at the L2/3 level. Preoperative spinal stenosis was associated with POSEH at the L2/3 level, and CSA of 56 mm2 was a predictive factor for POSEH. Logistic regression analysis revealed that both were significant risk factors. Conclusions: In patients undergoing m-MEL, the incidence of POSEH is highest at the L2/3 level, and treatment of the L2/3 level at the end of the procedure and the presence of spinal stenosis are risk factors for POSEH.

Traumatic intrathoracic foreign bodies are said to occur in many cases when the patient himself/herself is aware of the trauma. However, at the time of injury, the patient may sometimes be accompanied by loss of consciousness. We report a case of traumatic intrathoracic foreign body that was difficult to diagnose due to loss of consciousness at the time of injury.A 51-year-old female was brought to our emergency department with a fall trauma due to loss of consciousness while bathing. The head computed tomography and electrocardiogram showed no abnormalities, and the laceration of approximately 3 cm in length was found on the left side thorax, and it was sutured and the patient was sent home. Four days later, she returned to our hospital with a complaint of left anterior chest pain, and chest X-ray showed a left degree pneumothorax and mediastinal emphysema. She underwent semi-emergency thoracoscopic removal of the foreign body, and was discharged from the hospital on the fourth postoperative day.She had progressive supranuclear palsy, and her memory at the time of injury was not clear due to loss of consciousness caused by central autonomic neuropathy, and she also had dementia, making it difficult to interview her. She had no thoracic symptoms, and the glass fragment that had strayed into the thoracic cavity was not exposed outside the body, making the diagnosis difficult at the time of initial examination.When a patient with loss of consciousness is difficult to interview at the time of injury, it is advisable to perform an imaging examination appropriate for the site of injury, taking into consideration the presence of foreign bodies.

Abstract Background Cap polyposis (CP) is extremely rare in Japan, and there is no established cure. We report a case in which CP was improved by surgical treatment. Case presentation A 48-year-old man was investigated at a local hospital because of diarrhea and bloody stools in 2018. The patient was treated with metronidazole for suspected amoebic dysentery, but his symptoms did not improve. Subsequent close examination revealed possible CP, but treatment with 5-aminosalicylic acid and a steroid enema had no effect. The patient was then referred to our hospital. The bloody stools, diarrhea, and abdominal pain worsened despite medical treatment, so laparoscopic-assisted total proctocolectomy and ileal J-pouch anal anastomosis with ileostomy were performed. CP has no known cause or established treatment, but Helicobacter pylori (HP) infection has been reported in many CP cases in Japan, and HP eradication is often successful. This patient was HP-negative and did not improve with antimicrobial treatment, but the symptoms improved after surgery. Conclusions Even after surgery, CP recurrence reportedly occurs within a short period in many cases. However, our patient has had no signs of CP recurrence during 1 year of follow-up.

Abstract Background Crohn’s disease (CD) recurrence can occur not only at the site of anastomosis but also elsewhere in the bowel following an ileocolic resection (ICR) procedure. The aims of the present study were to assess long-term outcomes of a primary ICR procedure for CD in consecutive patients and examine the location of the reoperation causative lesion. Methods We examined cases of surgery with ICR initially performed at our institution. Those with simultaneous multiple bowel resection or bowel resection with strictureplasty were excluded. Results A total of 169 patients who underwent ICR due to CD were enrolled. The median follow-up period was 12.6 years (range 4–27 years). A reoperation was needed in 45 (26.6%), of whom 14 had lesions causative of the reoperation at other than the anastomotic site. The most common causative lesion location was in the colon rather than the oral side of the small intestine. Furthermore, we investigated the relationship between presence of residual lesions following the initial surgery and lesions causative of reoperation. In the group without residual disease (n = 31), 29.0% (n = 9) had non-anastomotic lesions involved in indications for reoperation, while that was 35.7% (n = 5) in the group with residual disease (n = 14). Conclusions Anastomotic site lesion is not the only causative factor for reoperation following ICR. Regular examinations and applicable treatment with awareness that the cause of reoperation is not limited to the site of anastomosis are important in these cases.

Abstract Gallbladder cancer is a biliary tract cancer that originates in the gallbladder and cystic ducts and is recognized worldwide as a refractory cancer with early involvement of the surrounding area because of its anatomical characteristics. Although the number of cases is increasing steadily worldwide, the frequency of this disease remains low, making it difficult to plan large‐scale clinical studies, and there is still much discussion about the indications for surgical resection and the introduction of multidisciplinary treatment. Articles published between 2019 and 2020 were reviewed, focusing mainly on the indications for surgical resection for each tumor stage, the treatment of incidental gallbladder cancer, and current trends in minimally invasive surgery for gallbladder cancer.

Abstract Background Cholangiolocellular carcinoma (CoCC) is an extremely rare disease comprising less than 1% of all primary malignant liver tumors. No effective treatment other than resection has been established. Herein, we report a case of locally advanced CoCC diagnosed as unresectable, which was successfully treated with curative resection after downsizing chemotherapy. Case presentation A 59-year-old Japanese woman with chronic hepatitis B was diagnosed with locally advanced intrahepatic cholangiocellular carcinoma. As it was difficult to perform R0 resection in the local hospital, chemotherapy combined with gemcitabine plus cisplatin was administered every 3 weeks. After a total of 10 courses of chemotherapy over 10 months the tumor was shown to be reduced in size by computed tomography imaging, and she was referred to our department for surgical resection. The effect of chemotherapy was classified as a “partial response” in the response evaluation criteria of solid tumors. After adding one course of chemotherapy, an extended left hepatectomy with resection of the caudate lobe was performed. R0 resection was achieved. Based on the pathological findings, the final diagnosis of CoCC was determined and eight courses of S-1 adjuvant chemotherapy were administered. At 14 months after the operation, the patient was alive without tumor recurrence. Conclusions Downsizing chemotherapy with gemcitabine and cisplatin may be an effective treatment strategy in locally advanced CoCC. Further evidence is required to establish an optimal strategy for the treatment of locally advanced CoCC.

Introduction: Lethal symptoms due to graft rejection warrant rapid removal of the transplanted graft to save the patient's life. We report a case of massive pancreas graft bleeding due to chronic rejection that necessitated graft removal after hemostasis by stent graft insertion. Case presentation: A 39-year-old woman underwent simultaneous pancreas-kidney transplantation for type I diabetes and chronic renal failure nine years ago. She suffered irreversible kidney damage from severe chronic rejection due to drug non-compliance. She was admitted to the emergency department for abdominal pain and bloody stools. She presented with signs of shock based on her vitals due to massive bleeding in the stool a day after hospitalization and required systemic management in the intensive care unit (ICU). Enhanced computed tomography (CT) scan revealed active bleeding from the duodenal portion of the pancreas graft. Hemostasis was achieved by inserting a stent graft into the right external iliac artery. The respiratory and circulatory status of the patient improved after the intervention, and she was transported to our hospital day after treatment. The graft was removed along with the part of the anastomosed intestine, which was reconstructed with a functional end-to-end anastomosis. Conclusion: We encountered a patient with hemorrhagic shock due to bleeding from a rejected pancreas graft. The patient was successfully treated and saved using stent-graft hemostasis followed by graft removal. Clinicians and surgeons should be mindful of chronic rejection, which could lead to life-threatening hemodynamic complications.

Abstract Background Iatrogenic acute aortic dissection (AAD) caused by cardiovascular intervention is rare. Also rare is spontaneous coronary artery dissection (SCAD), a form of acute coronary syndrome, which develops in relatively young women without coronary risk factors. We encountered type A iatrogenic AAD caused by an intervention for SCAD. Case presentation A 53-year-old woman was brought to our hospital after cardiopulmonary resuscitation. She was diagnosed with acute coronary syndrome caused by SCAD, and percutaneous coronary intervention was carried out on her distal left anterior descending artery. The dissection proceeded to the proximal left anterior descending artery and left main coronary artery trunk, so additional percutaneous coronary intervention was performed on the left circumflex artery. After the intervention, type A AAD occurred with a primary entry tear from the left main coronary artery trunk, and computed tomography showed a type A AAD of the aortic arch. We performed emergency ascending aorta replacement and coronary artery bypass grafting to the left anterior descending artery and left circumflex artery. The patient had an uneventful recovery after the operation and was discharged on postoperative day 25. Conclusion To our knowledge, this is the first report of an iatrogenic AAD caused by percutaneous coronary intervention for SCAD.

Abstract Background Frailty results in a high risk for disability, hospitalization, and mortality. This study aimed to investigate perioperative details of frail patients who underwent pancreatectomy and whether frailty can be a predictive factor of postoperative complications, especially of clinically relevant postoperative pancreatic fistula (CR-POPF). Methods This retrospective study included patients who underwent pancreatectomy in our hospital between August 2016 and March 2019. The patients were divided into frail and pre-/non-frail groups. The diagnostic criteria were based on the Japanese version of the Cardiovascular Health Study. Results Of 93 patients, 11 (11.8%) and 82 (88.2%) were frail and pre-/non-frail patients, with median ages of 82 and 72 years, respectively (p = 0.041). Postoperative complications (Clavien-Dindo ≧ IIIa) were found in 8 and 32 patients (p = 0.034), CR-POPF in 3 and 13 patients (p = 0.346), and postoperative hospital stays were 21 and 17 days (p = 0.041), respectively. On multivariate analysis, frailty was an independent predictive factor (odds ratio [OR] 5.604, 95.0% confidence interval [CI] 1.002-30.734; p = 0.047) of postoperative complications (Clavien-Dindo ≧ IIIa) after pancreaticoduodenectomy. On multivariate analysis, a soft pancreas (OR 5.696, 95.0% CI 1.142-28.149; p = 0.034) was an independent and significant predictive factor of CR-POPF after pancreaticoduodenectomy. Conclusions Frailty may be a useful predictive factor of postoperative complications in patients undergoing pancreaticoduodenectomy.

Abstract Background A large plexiform neurofibroma in patients with neurofibromatosis type I can be life threatening due to possible massive bleeding within the lesion. Although the literature includes many reports that describe the plexiform neurofibroma size and weight or strategies for their surgical treatment, few have discussed their possible physical or mental benefits, such as reducing cardiac stress. In addition, resection of these large tumors can result in impaired wound healing, partly due to massive blood loss during surgery. Case presentation A 24-year-old man was diagnosed with neurofibromatosis type I and burdened with a large plexiform neurofibroma on the buttocks and upper posterior thighs. The patient was 159 cm in height and 70.0 kg in weight at the first visit. Cardiac overload was indicated by an echocardiography before surgery. His cardiac output was 5.2 L/min with mild tricuspid regurgitation. After embolism of the arteries feeding the tumor, the patient underwent surgery to remove the neurofibroma, followed by skin grafting. Follow-up echocardiography, performed 6 months after the final surgery, indicated a decreased cardiac output (3.6 L/min) with improvement of tricuspid regurgitation. Because the blood loss during the first surgery was over 3.8 L, malnutrition with albuminemia was induced and half of the skin graft did not attach. Nutritional support to improve the albuminemia produced better results following a second surgery to repair the skin wound. Conclusion Cardiac overload may be latent in patients with neurofibromatosis type I with large plexiform neurofibromas. As in pregnancy, the body may compensate for this burden. In these patients, one stage total excision may improve quality of life and reduce cardiac overload. In addition, nutritional support is likely needed following a major surgery that results in either an extensive skin wound or excessive blood loss during treatment.

Abstract Background Although endoscopic interventions for chronic pancreatitis are highly developed, surgery for severe complicated cases such as the coexistence of bile duct, duodenum, and portal vein stenosis is a challenging issue for surgeons. In such instances, pancreaticoduodenectomy could lead to massive intraoperative bleeding due to severe collateral veins. A surgical drainage procedure, instead of pancreatic resection, may be a reasonable and safer option in such cases, but the literature on a surgical drainage technique to resolve all obstructions of the pancreatic duct, bile duct, and duodenum at once is limited. We devised a new surgical drainage method for such cases with consideration for a possible future second surgery for newly developed pancreatic cancer because chronic pancreatitis is a well-known high-risk factor for pancreatic cancer in the long term. Here, we report this surgical procedure. Case presentation A 55-year-old man was diagnosed with alcoholic chronic pancreatitis 15 years ago. Before surgery, he underwent regular endoscopic pancreatic stenting for pancreatic ductal stenosis for 3 years. Three months before surgery, his duodenal stenosis worsened, and he was referred to our department for surgery. Preoperative imaging revealed pancreatic and bile duct stenosis, duodenal stenosis, and portal vein stenosis. To avoid intraoperative bleeding caused by the development of collateral veins, we performed a triple drainage procedure: longitudinal pancreaticojejunostomy with coring-out of the pancreatic head, hepaticojejunostomy, and gastrojejunostomy. The patient did not develop postoperative complications, and he was discharged from the hospital on postoperative day 14. For 5 years after surgery, no abdominal pain or recurrent pancreatitis was observed. Conclusion Our triple drainage procedure seems effective and minimally invasive for patients complicated with bile duct stenosis, duodenal stenosis, and portal vein stenosis.

Abstract Background Numerous reports regarding sarcopenia have focused on the quantity of skeletal muscle. In contrast, the impact of the quality of skeletal muscle has not been well investigated. Methods A retrospective analysis of 115 patients who underwent initial hepatectomy for colorectal liver metastasis between January 2009 and December 2016 in our hospital was performed. Intramuscular adipose tissue content (IMAC) was used to evaluate the quality of skeletal muscle by analysing computed tomography (CT) images at the level of the umbilicus. The impact of poor skeletal muscle quality on short-term and long-term outcomes after hepatectomy for colorectal liver metastasis was analysed. Results Patients were divided into two groups (high IMAC and normal IMAC) according to their IMAC values, and their backgrounds were compared. There were no significant differences in most factors between the two groups. However, both body mass index (P = 0.030) and the incidence of postoperative complications of Clavien-Dindo grade 3 or worse (P = 0.008) were significantly higher in the high-IMAC group. In multivariate analyses, an operative blood loss > 600 ml (P = 0.006) and high IMAC (P = 0.008) were associated with postoperative complications of Clavien-Dindo grade 3 or worse. Overall survival and recurrence-free survival were significantly lower (P < 0.001 and P = 0.045, respectively) in the high-IMAC group than in the normal IMAC group. In multivariate analyses for poor overall survival, high IMAC was associated with poor overall survival (P < 0.001). Conclusions IMAC is a prognostic factor for poor short- and long-term outcomes in patients with colorectal liver metastasis.

Abstract Background There is no comprehensive agreement concerning the overall performance of radical resection for T1b gallbladder cancer (GBC). This research focused on addressing whether T1b GBC may spread loco-regionally and whether radical resection is necessary. Methods A retrospective analysis was conducted of 1032 patients with GBC who underwent surgical resection at our centre and its affiliated institutions between January 1982 and December 2018. A total of 47 patients with T1b GBC, 29 (62%) of whom underwent simple cholecystectomy and 18 (38%) of whom underwent radical resection with regional lymph node dissection, were enrolled in the study. Results GBC was diagnosed pre-operatively in 16 patients (34%), whereas 31 patients (66%) had incidental GBC. There was no blood venous or perineural invasion in any patient on histology evaluation, except for lymphatic vessel invasion in a single patient. There were no metastases in any analysed lymph nodes. The open surgical approach was more prevalent among the 18 patients who underwent radical resection (open in all 18 patients) than among the 29 patients who underwent simple cholecystectomy (open in 21; laparoscopic in 8) (P = 0.017). The cumulative 10- and 20-year overall survival rates were 65 and 25%, respectively. The outcome following simple cholecystectomy (10-year overall survival rate of 66%) was akin to that following radical resection (64%, P = 0.618). The cumulative 10- and 20-year disease-specific survival rates were 93 and 93%, respectively. The outcome following simple cholecystectomy (10-year disease-specific survival rate of 100%) was equivalent to that following radical resection (that of 86%, P = 0.151). While age (> 70 years, hazard ratio 5.285, P = 0.003) and gender (female, hazard ratio 0.272, P = 0.007) had a strong effect on patient overall survival, surgical procedure (simple cholecystectomy vs. radical resection) and surgical approach (open vs. laparoscopic) did not. Conclusions Most T1b GBCs represent local disease. As pre-operative diagnosis, including tumour penetration of T1b GBC, is difficult, the decision of radical resection is justified. Additional radical resection is not required following simple cholecystectomy provided that the penetration depth is restricted towards the muscular layer and that surgical margins are uninvolved.

Summary:. The successful reduction of a nasomaxillary fracture was performed using a three-dimensional printed model. A 16-year-old boy was struck in the left orbit by a baseball; subsequently, he was diagnosed with the nasal bone fracture at a hospital, and was referred to the authors’ department. A left nasomaxillary fracture and nasal bone fracture were diagnosed by computed tomography. Standard triangulated language data for the mirror image of the frontal process of the right maxilla were obtained from digital imaging and communications in medicine data for preparing a three-dimensional printed acrylonitrile butadiene styrene model. On postinjury day 13, the frontal process fracture was reduced via transconjunctival and intraoral approaches. After the reduction of the fracture, an absorbable plate fitting to the shape of three-dimensional printed acrylonitrile butadiene styrene model was molded, and the maxillary frontal process and infraorbital rim were reduced and fixed with an absorbable plate and screws. Postoperative computed tomography demonstrated a favorable reduction. The intraoperative use of the 3D printed acrylonitrile butadiene styrene model was helpful in the nasomaxillary fracture reduction and fixation.

Abstract Background The cystic duct has been included in the staging classification scheme for gallbladder cancer since the 2010 publication of the AJCC Cancer Staging Manual (7th edition). To our knowledge, only seven other cases of adenocarcinoma arising in the remnant cystic duct following cholecystectomy have been reported in the English-language literature, and none has been reported as primary early-stage T1b remnant cystic duct cancer (CDC). We report, herein, a case of primary adenocarcinoma arising in the remnant cystic duct in a patient with history of laparoscopic cholecystectomy for gallstone disease. Case presentation An 81-year-old female presented with abdominal pain. Her medical history included a laparoscopic cholecystectomy for cholecystolithiasis two years prior. Jaundice was observed; imaging studies suggested that this was caused by choledocholithiasis. Blood chemistry findings showed severe liver dysfunction. Endoscopic retrograde cholangiography revealed haemobilia from the common bile duct with no evidence of choledocholithiasis. A bile sample showed Papanicolaou class IV cytology. As the extent of tumour spread was undetermined by abdominal ultrasonography and endoscopic ultrasonography, peroral cholangioscopy (POCS) was performed, which revealed tiny papillary lesions within the confluence of cystic duct, and fine granular lesions in the centre of bile ducts, signifying early-stage remnant CDC. Extrahepatic bile duct resection with regional lymphadenectomy was done. Histopathological findings revealed a 42-mm tubular adenocarcinoma originating from the remnant cystic duct with the considerable shallow spread across the extrahepatic bile ducts. It invaded the fibromuscular layer, with no lymphovascular or perineural invasion, no lymph node metastasis (13 nodes examined), and uninvolved surgical resection margin (R0 resection), and was staged as pT1bN0M0, Stage I. Conclusions Primary early-stage T1b remnant CDC is an uncommon condition for which early diagnosis is challenging; if intraoperatively recognized, it can complicate surgery. Our experience of this case and an overview of the English literature suggest that POCS is an efficient tool to diagnosis this tumour and assess its spread along the extrahepatic bile ducts.

Abstract Background Expression of High-Mobility Group Box 1 (HMGB1), a multifunctional protein involved in DNA function as well as cell proliferation, inflammation, and the immune response, has been reported to be prognostic in several types of malignancies. However, the prognostic value of HMGB1 in ampullary cancer has not been studied. Methods Patients with adenocarcinoma of the ampulla of Vater who underwent R0 resection with pancreaticoduodenectomy between 2001 and 2011 were included in the present multi-institutional study. The degree of HMGB1 expression was examined in each resected specimen by immunohistochemical staining. Results A total of 101 patients were enrolled of which, 79 patients were eligible. High expression of HMGB1 was observed in 31 (39%) patients. Blood loss, transfusion, tumor stage, nodal status, and HMGB1 expression were identified as predictors with univariate analysis. Multivariate analysis showed that transfusion, lymph-node metastasis, and high HMGB1 expression were independent predictors of poor overall survival. Subgroup analysis showed that high HMGB1 expression was predictive, especially in patients who did not receive adjuvant chemotherapy. Conclusions High HMGB1 expression is an independent predictor of poor prognosis in patients with adenocarcinoma of the ampulla of Vater not treated with adjuvant chemotherapy.

Objectives: A number of patients have developed liver failure after the Kasai operation for biliary atresia (BA), even after long-term postoperative course. We report our experience regarding four cases of biliary atresia required and treated with living donor liver transplantation (LDLT) during adulthood. Methods: All four patients underwent Kasai operation for BA from 1974 to 1983 and had been followed-up for more than 30 years in our institute. Then, they developed liver failure and treated with LDLT. These four patients’ records were reviewed retrospectively. All data are described using the median value. Results: Three female and one male were included. Kasai operation was performed at the age of 61 days. The type of biliary obstruction was type III-b1-ν in all. The survival period of the native liver was 440 months. The age at LDLT was 37 years. The reasons of deterioration of native liver were recurrent cholangitis in two and pregnancy and delivery in other two. The age of living donor was 40 years. Right liver grafts were used in all. Percentage of the real graft volume per standard liver volume was 47%. All patients were alive and overall graft survival rate was 100% at a follow-up period of 65 months after LDLT. Conclusion: Even after more than 30 year-survival with native liver after Kasai operation, liver failure may be caused by recurrent cholangitis or pregnancy and delivery. LDLT may be effective treatment for those adult patients if an adequate living donor is available.

Summary: Background: Heterotopic ossification (HO) occurs frequently in the elbow in burn patients, and extends beyond the anatomical structure. HO of the elbow can cause joint contracture and adversely affect activities of daily living.Currently, there is no effective prophylaxis for HO as the precise underlying mechanism remains unknown. Therefore, there is no choice but to treat HO after it has developed. To date, however, no effective standard treatment has been reported, and therefore treatment methods vary between different facilities. Surgical resection is widely accepted as the only therapeutic option once HO limits functional mobility of the elbow. Purposes: Based on past reports, we examined our cases and recommend effective therapeutic strategies. We posed the following three questions: (1) Is the surgical intervention effective or detrimental for elbow ankylosis due to HO? (2) What is the best timing for the intervention? (3) What is the most effective postoperative rehabilitation plan? Methods: We treated three patients with complete ankylosis of the elbow due to HO after severe burn injury using different protocols. Results: Surgery was performed in two cases and rehabilitation therapy was commenced immediately from the first postoperative day. Both patients showed improvement in the active range of motion in their elbow joints. The other patient did not undergo surgery, and his elbows became fixed in the completely extension position. Conclusion: Surgical resection is beneficial for elbow ankylosis due to HO after burn injury. Although the exact surgical timing is still controversial, we recommend that surgery should be performed as soon as possible after improving the skin condition around the elbow and confirming the maturation of HO on radiographs. Early rehabilitation and pain control are also important after surgery. Keywords: Heterotopic ossification, Burn, Surgical resection, Elbow, Rehabilitation, Ectopic bone

Abstract Background Neuroendocrine tumors (NETs) of the gallbladder are rare and generally considered low-grade malignancies. We herein describe a case of a patient with a 0.8-cm clear cell NET G1 of the gallbladder with nodal involvement. Case presentation A 65-year-old man with no medical history indicative of von Hippel-Lindau (VHL) disease underwent laparoscopic cholecystectomy for cholecystolithiasis. There was a 0.8-cm tumor in the neck of the gallbladder. Histologic examination revealed nests or trabecular growth of clear cells with small round-to-oval nuclei. Immunohistochemically, tumor cells showed positivity for chromogranin A and synaptophysin; Ki-67 index was

Abstract Background Laparoscopic surgery for patients with portal hypertension is considered to be contraindicated because of the high risk of massive intraoperative hemorrhaging. However, recent reports have shown hand-assisted laparoscopic surgery for devascularization and splenectomy to be a safe and effective method of treating esophagogastric varices with portal hypertension. The aim of this study is to evaluate the efficacy of hand-assisted laparoscopic devascularization and splenectomy (HALS Hassab’s procedure) for the treatment of esophagogastric varices with portal hypertension. Case presentation From 2009 to 2016, seven patients with esophagogastric varices with portal hypertension were treated with hand-assisted laparoscopic devascularization and splenectomy in our institute. Four men and three women with a median age of 61 years (range 35–71) were enrolled in this series. We retrospectively reviewed the medical records for the perioperative variables, postoperative mortality and morbidity, and postoperative outcomes of esophagogastric varices. The median operative time was 455 (range 310–671) min. The median intraoperative blood loss was 695 (range 15–2395) ml. The median weight of removed spleen was 507 (range 242–1835) g. The conversion rate to open surgery was 0%. The median postoperative hospital stay was 21 (range 13–81) days. During a median 21 (range 3–43) months of follow-up, the mortality rate was 0%. Four postoperative complications (massive ascites, enteritis, intra-abdominal abscess, and intestinal ulcer) were observed in two patients. Those complications were treated successfully without re-operation. Esophagogastric varices in all patients disappeared or improved. Bleeding from esophagogastric varices was not observed during the follow-up period. Conclusion Although our data are preliminary, hand-assisted laparoscopic devascularization and splenectomy proved an effective procedure for treating esophagogastric varices in patients with portal hypertension.

Abstract Background Ulcerative colitis (UC) is known as an immune disorder of the colon that generally involves the rectum, but an atypical distribution of inflamed mucosa has previously been noted in certain subtypes of UC, such as the rectal-sparing type (RST). As noted in a previous report, patients with the RST may be at elevated risk for disease refractoriness, but the clinical significance of RST remains unknown. Methods UC patients who underwent surgery between January 2010 and April 2015 were included. Patients were classified as having the RST or a non-RST based on colectomy specimens or a pre-operative endoscopy. Possible risk factors for urgent/emergent surgery were analyzed. We specifically determined whether the RST is a significant predictor for urgent/emergent surgery. Results In total, 46/482 patients were classified as having the RST. Disease severity was significantly worse in patients with the RST than in other patients (p = 0.02). Urgent/emergent surgery was required for 24/46 patients with the RST, compared with 107/436 non-RST patients (p

We report a case in which elbow flexion exercises using the upper limb single-joint Hybrid Assistive Limb (upper limb HAL-SJ) were implemented in a patient 13 months postoperatively following elbow flexion reconstruction with intercostal nerve transfer after a traumatic brachial plexus injury. Treatment using the upper limb HAL-SJ was administered once a week for 10 sessions from 13 to 16 months after surgery. Exercises using the upper limb HAL-SJ supported elbow motion by detecting bioelectric signals through surface electrodes on the biceps and triceps brachii. No adverse events were observed during treatment with the upper limb HAL-SJ. Improvements in elbow flexion strength were observed during treatment. Treatment with the upper limb HAL-SJ can be performed safely and effectively following elbow flexion reconstruction by intercostal nerve transfer after a traumatic brachial plexus injury.

Incomplete or asymmetrical conjoined twins are extremely rare congenital anomalies. We report a case of epigastric heteropagus associated with an omphalocele and double outlet right ventricle. The cystic legion of the epigastrium was detected in our patient by an ultrasound scan at 28 weeks' gestation. He was born at 37 weeks' gestation by scheduled caesarean section. A parasite with an incomplete head and lower limb was attached to the epigastrium of the autosite. Surgical separation of the parasite and silo placement for an omphalocele was successfully performed on the 4th day of life. He underwent secondary surgical closure of the omphalocele on the 10th day. For treatment of the cardiac anomaly, he underwent an operation of Blalock–Taussig shunt because of pulmonary artery stenosis at the age of 3 months and correction of double outlet right ventricle at the age of 10 months. At the 20-month follow-up, he was alive and showed a normal growth pattern.

Summary: Recent advances in 3-dimensional (3D) surface imaging technologies allow for digital quantification of complex breast tissue. We performed 11 unilateral breast reconstructions with deep inferior epigastric artery perforator (DIEP) flaps (5 immediate, 6 delayed) using 3D surface imaging for easier surgery planning and 3D-printed molds for shaping the breast neoparenchyma. A single- or double-pedicle flap was preoperatively planned according to the estimated tissue volume required and estimated total flap volume. The DIEP flap was then intraoperatively shaped with a 3D-printed mold that was based on a horizontally inverted shape of the contralateral breast. Cosmetic outcomes were assessed as satisfactory, as confirmed by the postoperative 3D measurements of bilateral breasts. We believe that DIEP flap reconstruction assisted with 3D surface imaging and a 3D-printed mold is a simple and quick method for rebuilding a symmetric breast.

Background: In a previous study, the authors outlined a technique for calculating the number of abnormal vascular loop structures described in 3-dimensional computed tomography angiography. To be developed into a quantitative evaluation method for soft-tissue arteriovenous malformations (AVMs), the concept needs assessment of validity. Methods: Computed tomography angiography results of 19 soft-tissue AVMs and 18 control abdominal vessels are utilized. Enhanced vascular lumen regions over 120 HU were extracted by a region growing method and skeletonized into wire frame graph models. The number of vascular loop structures in graphs is calculated as 1 − [Number of nodes] + [Number of edges], and results are compared between AVM/control groups, pre-/postprogression, and pre-/posttreatment. Results: Average vascular lumen capacity of AVMs was 57.5 ml/lesion, and average number of vascular loops was 548 loops/lesion. Loop density of AVMs (weighted average, 9.5 loops/ml) exhibited statistically significant (P < 0.001) greater value than normal abdominal blood vessels (weighted average, 1.3 loops/ml). In all 4 cases without treatment, number of loops and loop density both increased. Particularly, number of loops increased greatly by 2 times or more in 3 cases. In all 7 cases with treatment, number of loops and vascular lumen capacity significantly (P = 0.0156) decreased. Particularly, number of loops showed clearer decrease in cases with entire lesion treatment than partial treatment. Conclusions: Total number of described vascular loop structures and their density or volume well reflected the existence, progression, and remission of soft-tissue AVMs. Topological analysis can be expected to be developed into a quantitative evaluation for AVMs.

Background: Evaluating the progression of soft-tissue arteriovenous malformation (AVMs) is still problematic. To establish a quantitative method, we took a morphological approach. Methods: Normal blood vessels in early-phase 3D-computed tomography angiography images are theoretically expected to be tree-like structures without loops, whereas AVM blood vessels are expected to be mesh-like structures with loops. Simplified to the utmost limit, these vascular structures can be symbolized with wire-frame models composed of nodes and connecting edges, in which making an extra loop always needs one more of edges than of nodes. Results: Total amount of abnormal vascular structures is estimated from a simple equation: Number of vascular loops = 1 − ([Number of nodes] − [Number of edges]). Conclusion: Abnormalities of AVM vascular structures can be mathematically quantified using computed tomography angiography images.