Search

Abstract: In the past decade, rapid technical developments and advancements of multidetector computed tomography (MDCT) have revolutionized the preoperative imaging evaluation of thoracic vascular and tracheobronchial anomalies and abnormalities in infants and children. Multidetector computed tomography enables noninvasive, rapid, high-resolution, and 3-dimensional (3D) imaging of the thorax in pediatric patients that provides comprehensive preoperative surgical guidance for pediatric surgeons. With the increasing availability of MDCT and 3D imaging, a practical review is needed for the pediatric surgeon of the evolving role of these techniques in the preoperative evaluation of surgical lesions in infants and children. This article focuses on the review of advantages and disadvantages of MDCT in comparison to other imaging modalities, 2D and 3D imaging postprocessing techniques, and MDCT and 3D imaging appearance of various thoracic vascular and tracheobronchial anomalies and abnormalities in pediatric patients. The primary aim of this article was to facilitate the pediatric surgeons'' ability to successfully incorporate MDCT and 3D imaging as a routine preoperative imaging tool for the evaluation of thoracic surgical lesions in infants and children. [Copyright &y& Elsevier]

Abstract: Purpose: The rarity and histopathologic diversity of primary pancreatic neoplasms in children have made it difficult to predict prognosis and to develop optimal management protocols. Methods: A 90-year (1918-2007), single institution, retrospective review of all patients with neoplastic pancreatic masses was performed. Results: Eighteen patients were identified with 7 distinct histopathologic subtypes. The most common were gastroenteropancreatic neuroendocrine, solid pseudopapillary, and acinar tumors. There were 6 benign and 12 malignant tumors. Six patients had disease outside the pancreas at their initial operation. There were 7 deaths (41%), 2 related to the initial operation, 3 from disease progression, 1 from a small bowel obstruction, and 1 from necrotizing pancreatitis. Five deaths were in patients with extrapancreatic disease found at initial operation. The median duration of follow-up for the 10 survivors was 41 months. Conclusion: In adults, pancreatic ductal adenocarcinoma is by far the most common histopathologic subtype, with other subtypes more common in children. Stage is an important prognostic factor. Long-term disease-free survival in childhood pancreatic malignancies is achievable with complete surgical resection, prognosis, and adjuvant treatment, depending on the histopathologic type. [Copyright &y& Elsevier]

Abstract: This study used retrospective review of patients with critical airway due to compression by an anterior mediastinal mass treated at a single pediatric teaching institution. Diagnostic workup is reviewed with a focus on diagnostic biopsy. Algorithm for streamlining the choice of biopsy technique and minimizing invasive procedures is suggested. [Copyright &y& Elsevier]

Abstract: Background: Rib lesions in the pediatric population are rare but significant processes and are often neoplastic. Methods: All patients with primary rib lesions evaluated by the Department of Surgery at Children''s Hospital Boston from 1992 to 2005 were studied. The patient''s diagnosis, sex, symptoms and their duration, radiologic evaluation, biopsy status, surgical procedure, and follow-up were assessed. Results: Thirty-three patients, ages 3 to 23 years (median, 12.7 years), were evaluated. Sixteen patients (48%) had benign and 17 (52%) had malignant lesions. Within the benign cohort of 16 patients, there were 6 osteochondromas, 4 aneurysmal bone cysts, and 2 fibrous dysplasias as well as 1 of each of the following: enchondroma, periosteal chondroma, eosinophilic granuloma, and chondrophyte. Within the malignant cohort of 17 patients, 13 were diagnosed with Ewing''s sarcoma, 3 with osteogenic sarcoma, and 1 with chondrosarcoma. The sex distribution for the malignant group was 11 (65%) females and 6 (35%) males. Conclusions: Rib tumors are rare entities in the pediatric population. However, a significant number of rib lesions are malignant. Therefore, proper diagnosis and expeditious treatment are critical. [Copyright &y& Elsevier]

Abstract: Background: Extension of Wilms'' tumor into the ureter is a rare event. We reviewed the National Wilms'' Tumor Study Group (NWTSG) database to define the clinical presentation, associated pathologic features, and clinical outcome of these patients. Methods: Records of children identified to have ureteral extension of Wilms'' tumor enrolled in NWTS-3, 4, and 5 were reviewed. Presenting symptoms, diagnostic studies, histopathologic findings, operation performed, and outcome were recorded. The NWTS-5 surgical data were prospectively collected as part of the quality assurance program. Results: Forty-five children were identified with ureteral extension. For NWTS-5, the incidence of ureteral extension was 2%. Clinical presentations were gross hematuria in 22 patients, 2 had passage of tissue per urethra, and 1 child had a urethral mass. The remainder had nonspecific presentations. Ureteral extension was seen on preoperative imaging in 14 patients, intraoperatively in 22, and on pathologic examination in 9 patients. Hydronephrosis was noted in 12 patients, and there was nonfunction of the kidney in another 8. Laterality of the tumor was right side in 26 and left in 19. Cystoscopy was performed in 12 children. Findings included tumor seen at the ureteral orifice in 6 patients and bleeding from the orifice in one child. All patients had radical nephrectomy including partial ureterectomy. The ureteral margin was positive in 3 patients, including 2 of the 7 with separate removal of the ureteral extension. The number of patients in each clinical stage was as follows: stage I, 10; stage II, 18; stage III, 14; and stage IV, 3. The tumor extended into the proximal ureter in 23 patients, distal ureter in 13, 7 had extension into the bladder, and 1 had urethral involvement. The level of ureteral extension was not clearly noted in the 45th child. The median follow-up was 96 months. Overall, 41 of 45 patients were alive at last contact. There were 3 deaths because of tumor in patients with unfavorable histologic tumors, and 1 because of treatment toxicity in a child with favorable histologic findings. Conclusions: Ureteral extension occurs in approximately 2% of patients with Wilms'' tumor. The diagnosis should be suspected in patients with gross hematuria, hydronephrosis, or nonfunctioning kidney. Cystoscopy with retrograde ureterogram may aid in preoperative diagnosis in these patients. Preoperative diagnosis is important because complete resection of the involved portion of ureter at the time of nephrectomy can avoid residual disease and the need for second surgery or radiation therapy. [Copyright &y& Elsevier]

Pediatric pulmonary tumors are rare. There is often a significant delay in diagnosis of pulmonary tumors secondary to their rarity and nonspecific presenting physiologic and radiographic findings. A high index of suspicion in pediatric patients with recurrent or persistent pulmonary symptoms is of paramount importance in diagnosing pulmonary tumors at an early stage. Malignant pulmonary tumors are more frequently diagnosed than benign lesions, with metastatic cancers being the most common. Complete surgical resection remains the basis of therapy for primary lesions, and its role in secondary cancers is becoming more established. Adjuvant therapies are frequently employed depending on the precise tumor involved. Mortality rates vary greatly depending on tumor location, stage, and type. [Copyright &y& Elsevier]

Background: Given widespread adoption of the Nuss procedure, prospective multicenter study of management of pectus excavatum by both the open and Nuss procedures was thought desirable. Although surgical repair has been performed for more than 50 years, there are no prospective multicenter studies of its management. Study Design: This observational study followed pectus excavatum patients treated surgically at 11 centers in North America, according to the method of choice of the patient and surgeon. Before operation, all underwent evaluation with CT scan, pulmonary function tests, and body image survey. Data were collected about associated conditions, hospital complications, and perioperative pain. One year after completion of treatment, patients will repeat the preoperative evaluations. This article addresses early results only. Results: Of 416 patients screened, 327 were enrolled; 284 underwent the Nuss procedure and 43 had the open procedure. Median preoperative CT index was 4.4. Pulmonary function testing before operation showed mean forced vital capacity of 90% of predicted values; forced expiratory volume in 1 second (FEV1), 89% of predicted; and forced expiratory flow during the middle half of the forced vital capacity (FEF25% to 75%), 85% of predicted. Early postcorrection results showed that operations were performed without mortality and with minimal morbidity at 30 days postoperatively. Median hospital stay was 4 days. Postoperative pain was a median of 3 on a scale of 10 at time of discharge; the worst pain experienced was the same as was expected by the patients (median 8), and by 30 days after correction or operation, the median pain score was 1. Because of disproportionate enrollment and similar early complication rates, statistical comparison between operation types was limited. Conclusions: Anatomically severe pectus excavatum is associated with abnormal pulmonary function. Initial operative correction performed at a variety of centers can be completed safely. Perioperative pain is successfully managed by current techniques. [Copyright &y& Elsevier]

Abstract: Purpose: The purpose of this article is to describe the outcomes of the pouches of 14 children with ulcerative colitis (UC) who were pretreated with calcineurin inhibitors before they underwent their ileal pouch anal anastomosis (IPAA) surgery. Methods: An institutional review board–approved retrospective review of the charts of consecutive patients with UC treated with calcineurin inhibitors before undergoing IPAA surgery at a tertiary pediatric center between 1998 and 2003 was performed. The primary endpoint was pouch outcome after at least 2 years of follow-up (healthy pouch, acute pouchitis, chronic refractory pouchitis, or pouch failure); the secondary endpoints were early postoperative complications, number of stages, and time between stages. Results: Fourteen of 53 consecutive patients who underwent IPAA for UC were treated with calcineurin inhibitors before their surgery (26%; 6 with cyclosporine and 8 with tacrolimus). All 14 patients were concomitantly treated with systemic steroids. Ten patients (71%) were also taking 6-mercaptopurine or azathioprine, and 9 (64%) were also taking mesalamine. Three patients (21%) had healthy pouches with no clinical evidence of pouchitis, 6 (43%) had at least one episode of acute pouchitis (average of 2 episodes per year), 3 (21%) had chronic relapsing pouchitis, and 2 (14%) were later determined to have Crohn''s disease. There was no pouch failure. Two patients (14%) had an early postoperative complication (intraabdominal abscess, anastomotic stricture). Five patients (36%) had a 2-staged procedure, and 8 (64%) had a 3-staged procedure. For the 2-staged procedures, the mean time between the first and second stages was 3.14 months (range, 3-4 months). For the 3-staged procedures, the mean time between the first and second stages was 4.25 months (range, 2-6 months) and that between the second and third stages was 4 months (range, 2.5-6 months). Conclusions: In this series, chronic pouchitis was an infrequent complication among children who were pretreated with calcineurin inhibitors. Calcineurin inhibitor use did not lead to or portend increased early postoperative complications or affect the number or duration of surgical stages. Further studies are required to determine if preoperative calcineurin inhibitors improve pouch outcomes or facilitate the performance of 2-staged procedures. [Copyright &y& Elsevier]

Abstract: Purpose: The purpose of this study was to evaluate whether initial diagnostic technique influenced the ability to identify anaplastic histology, to determine the time interval to diagnosis of anaplasia, and to delineate the incidence of discordant pathology in bilateral Wilms'' tumor. We hypothesized that delay in diagnosis of anaplasia could affect time to appropriate surgery and intensive multimodality therapy. Methods: One hundred eight-nine children were enrolled in the fourth National Wilms'' Tumor Study with synchronous bilateral tumors, 27 of whom were eventually shown to have anaplastic histology. Initial diagnostic technique, time interval to diagnosis of anaplasia, and the incidence of discordant pathology were determined. Results: Anaplasia was identified in 0 of 7 tumors by core needle biopsy, 3 of 9 tumors by open wedge biopsy, and in 7 of 9 cases by partial or complete nephrectomy. The mean duration of first chemotherapy regimen (DD or EE) was 20, 39, and 36 weeks, respectively, before anaplasia was identified at second surgery. Discordant pathology between bilateral tumors was identified on final tissue diagnosis in 20 patients. Only 4 patients had anaplastic tumors in both kidneys. Conclusions: Core needle biopsy did not identify anaplasia in 7 of 7 children. Open biopsy or partial/complete nephrectomy identified anaplasia at initial diagnostic procedure in 10 of 18 children. Twenty of 24 patients at final tissue diagnosis had discordant pathology between the 2 kidneys. Earlier interval incisional biopsy or resection may identify anaplastic histology and limit the duration of chemotherapy targeted to favorable histology for children with bilateral Wilms'' tumor and anaplasia. [Copyright &y& Elsevier]

Abstract: Background: To provide guidelines for future cooperative group trials, we reviewed the outcomes of children with bilateral Wilms'' tumors (BWTs) treated on National Wilms Tumor Study-4 (NWTS-4) who had progressive or nonresponsive disease (PNRD). Methods: NWTS-4 enrolled 3335 patients from August 1986 to September 1994 including 188 patients with BWT (5.6%). Treatment and outcome data were collected on patients with BWT. Treatment guidelines were outlined in the protocol, but patients were not on study. Results: Thirty-eight children with BWT had PNRD. Preoperative chemotherapy was given for a median of 7 months (range, 2-29 months) before definitive resection. After the initial chemotherapy regimen, 36 children went on to a second regimen, and of these, 21 children received a third regimen before resection. Eleven patients received irradiation to one or both kidneys. Pathology at resection revealed previously undiagnosed anaplasia in 3 patients (2 diffuse and 1 focal) treated for 14, 15, and 15 months before resection. A fourth patient developed a diffusely anaplastic tumor 13 months after therapy. Other pathological findings included rhabdomyomatous (4 patients) or differentiated stromal elements (10 patients) and complete necrosis (1 patient). Ten kidneys from 7 patients lacked biopsy at presentation or pathology review of those specimens. Conclusions: BWT patients with PNRD received prolonged courses of chemotherapy. Early and sequential biopsies to establish the reason for failure to respond should be obtained. This will identify anaplastic tumors managed best by early nephrectomy and intensive chemotherapy and will also distinguish differentiated tumors that are best managed with early resection, but less intensive therapy after nephrectomy. [Copyright &y& Elsevier]

Abstract: Background/Purpose: Computed tomography (CT) of the chest with its increased sensitivity frequently identifies lesions not visible on chest radiograph. Treatment of such lesions is controversial. A recent review suggests that patients with Wilms'' tumor with pulmonary lesions detected only by CT, who were treated with dactinomycin and vincristine, have an inferior outcome compared with those who also received pulmonary radiation therapy (RT) and doxorubicin. It is important to determine if these small lesions seen only on CT represent metastatic disease and whether patients with these lesions require RT and/or doxorubicin for optimal outcome. Methods: Patients with Wilms'' tumor with lung metastasis, registered on National Wilms'' Tumor Study 5, were reviewed, and those with CT-only lesions who had a radiology and surgical checklist submitted were identified. The treatment regimens of these patients and the histological findings of the pulmonary lesions are presented. We analyzed the pathological findings by whether the patients had single or multiple lesions. Results: Of 2498 patients registered on National Wilms'' Tumor Study 5, 252 had pulmonary metastases. Of these patients, 129 (5.2%) had CT-only lesions (<1 cm). Forty-two of these patients (20 boys and 22 girls) underwent lung biopsy at the discretion of the attending physicians. The local tumor stages in these patients were stage I (7%), II (34%), and III (59%). The treatment stages in these patients were stage I (n = 3, 2 drugs), II (n = 3, 2 drugs), III (n = 12, 3 drugs); and IV (n = 24, 3 drugs + RT). There were 16 patients with isolated lung lesions and 26 with multiple lesions, average size 5.8 ± 0.5 mm. Of 16 isolated lesions, 13 patients (82%) and 69% (18/26) with multiple lesions had tumor on biopsy. Of the 24 who received RT, 8 had a negative biopsy and, thus, may not have needed the RT. Five of 6 treated with just 2 drugs may have been undertreated. Nine of 12 treated with 3 drugs had tumor on biopsy. Conclusions: Computed tomography–only pulmonary lesions are not invariably tumor, demonstrating the need for histopathological confirmation. Biopsy remains critical until radiographic techniques allow differentiation between benign and malignant lesions to optimally direct therapy. [Copyright &y& Elsevier]

Although recent results of percutaneous imaging-guided radiofrequency ablation (RFA) of various tumors in adults are promising, RFA of tumors in children has been performed in only a small number of cases. We describe the treatment of Wilms tumor in a solitary kidney in a 5-year-old girl using percutaneous CT-guided RFA. The procedure provided short-term palliation in this child for whom partial or total nephrectomy carried high risk and low likelihood of success. Although it might only be useful ultimately as a temporizing measure, oncologists and surgeons might wish to consider RFA in children who would otherwise require dialysis and renal transplantation or who are poor surgical candidates. Various specific technical issues differentiate pediatric from adult tumor ablation, including the amount of intra-abdominal fat, need for smaller grounding pads, and potential systemic effects of tissue heating. [ABSTRACT FROM AUTHOR]

Increased catecholamine secretion from neuroblastomas can occasionally be demonstrated, but severe hypertension is uncommon. We report the perioperative management of a 5 year old child with stage III adrenal neuroblastoma who presented with malignant hypertension and high norepinephrine and dopamine levels. Hypertensive crises occurred during anesthesia for surgical biopsy and during chemotherapy. After blood pressure control using phenoxybenzamine and enalapril, doxazosin was used successfully as the preoperative α-adrenergic receptor antagonist for surgical tumor resection. [ABSTRACT FROM AUTHOR]

Abstract: Background: Inflammatory myofibroblastic tumors (IMTs) are neoplasms that are highly vascularized, have an intermediate prognosis, and are associated with infiltration, obstruction, local recurrence, and rare metastasis. Resection of large IMTs can lead to substantial morbidity and even mortality. Anecdotal experience suggests that nonsteroidal anti-inflammatory drugs may eradicate large IMTs or shrink them to a more readily resectable size and configuration. To support the hypothesis that nonsteroidal anti-inflammatory drugs are antiangiogenic for IMTs by interfering with vascular endothelial growth factor (VEGF) signaling via cyclooxygenase 2 (COX-2) inhibition, IMT specimens were immunohistochemically examined for expression of COX-2 enzyme and VEGF. Methods: The diagnosis of IMT was confirmed in all 18 cases comprising the study. Intensity of COX-2 and VEGF staining was graded, and staining uniformity was examined. ALK-1 protein expression, found in up to two thirds of IMTs, was also determined. Results: COX-2 and VEGF expression were identified in all tissue examined, with staining intensity varying independently. ALK-1 protein expression was identified in 33% of specimens. Its presence was not related to the intensity of COX-2 or VEGF staining. Conclusions: Our data suggest that the mediators of angiogenesis, VEGF and COX-2, are present and may play an important role in the growth of IMTs. [Copyright &y& Elsevier]

Abstract: Background/Purpose: The treatment approach for patients with high-risk neuroblastoma has been one of dose intensification chemotherapy and aggressive treatment of the primary tumor. Local tumor control is examined in high-risk patients treated with tandem stem cell transplant, aggressive surgery, and selected radiation therapy (XRT). Methods: Seventy-six patients with high-risk stage III/IV neuroblastoma were treated on a standard protocol incorporating aggressive surgical resection with or without local XRT followed by tandem high-dose chemotherapy and stem cell rescue. Patients were evaluated for degree of surgical resection, site of progression, and outcome. Results: Overall event-free survival for the series is 56%. Forty-eight had gross total resection, 12 had greater than 90% resection, 10 had 50% to 90% resection, and 6 had biopsy only or no surgery. Surgical complications occurred in 29% with no deaths. There were no isolated local failures. Two patients had local recurrence after gross total resection. Surgeon assessment of completeness of resection agreed with postoperative radiological findings 66% of the time. Conclusion: Aggressive surgical treatment with local XRT and myeloablative chemotherapy with stem cell rescue provides excellent local control in high-risk neuroblastoma, although distant failures, particularly osseous, remain a problem. Poor correlation exists between the surgeon''s perception of completeness of resection and findings on postoperative imaging studies. [Copyright &y& Elsevier]

Failure of an ileal pouch-anal anastomosis may result in unsuccessful completion of the anastomosis or removal of an ischemic pouch. We report a technique for preservation of the muscular wall of the rectum after mucosal dissection, which allowed a successful delayed pull-through. [ABSTRACT FROM AUTHOR]

We report a case of ossifying renal tumor of infancy, which presented as a palpable abdominal mass in an otherwise asymptomatic 10-month-old girl. The tumor was partially calcified and occupied the renal pelvis, causing severe hydronephrosis. The differential diagnosis for a patient this age included Wilms tumor, extra-adrenal neuroblastoma, infection, calculus, calcified hematoma and ossifying renal tumor of infancy. The child underwent heminephrectomy and is currently doing well. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: We reviewed the long-term local tumor control in patients with bilateral Wilm''s tumor (BWT) who received no definitive surgical therapy to one kidney after complete radiographic resolution after initial chemotherapy. Methods: National Wilm''s Tumor Study 4 (NWTS-4) enrolled 3335 patients (pts) during the period August 1986 to August 1994. There were 188 pts with BWT or 5.6% of the total enrolled. The treatment records and imaging reports were reviewed to ascertain those children who had documented tumors without definitive surgical therapy after initial treatment. Patients who did not have renal surgery because of progression of tumor were excluded from this study. Results: Eleven children had no definitive surgical treatment of renal lesions in one kidney (right, 6; left, 5) after initial treatment with chemotherapy and/or radiation therapy. The pretreatment size of the lesions were less than 3 cm (4 pts), 3 to 6 cm (5 pts), more than 6 cm (1 pt), and unknown (1 pt). Prechemotherapy biopsy was performed in 6 of 11 patients. Lesions were less than 3 cm (1 pt), 3 to 6 cm (3 pts), more than 6 cm (1 pt), and unknown (1 pt). Four biopsy specimens showed favorable Wilm''s histologic findings. One lesion (4 cm) showed an intralobar nephrogenic rest, another lesion of unknown size was read as favorable histologic findings vs perilobar nephrogenic rest. Biopsy was not performed on 5 lesions (4 pts, <1 cm; 1 pt, 3cm). Only 2 children in this study received radiation treatment. One child received 1050 cGy whole abdominal radiation, and 1 child received 1060 cGy to the left flank postnephrectomy. Radiation therapy was not given to any patient because of failure of the tumor to respond to chemotherapy. Five patients received treatment regimen EE-4A, dactinomycin, and vincristine. The duration of therapy ranged from 24 to 102 weeks for an average of 55.6 weeks. Three patients received treatment regimen DD-4A, dactinomycin, vincristine, and doxorubicin for 28, 52, and 52 weeks, respectively. Three patients received 2 separate regimens of chemotherapy. One child was treated with dactinomycin, vincristine, and cyclophosphamide for 60 weeks and then received regimen EE-4A for 24 weeks. Another patient received regimen EE-4A for 16 weeks and then regimen DD4-A for 36 weeks. One child received regimen EE-4-A for 12 weeks and then regimen DD4A for 40 weeks. Management of the contralateral kidney was complete nephrectomy in all 11 patients. There were no local relapses in the renal tumor bed. All patients were alive at a median follow-up of 9 years (range, 9 months to 15 years). Conclusion: Children with synchronous BWT or Wilm''s tumor and contralateral nephrogenic rests that have radiographic resolution, after initial treatment, have a low risk for local relapse. These children should be followed by serial imaging. [Copyright &y& Elsevier]

ABSTRACT: Purpose:: In children undergoing nephrectomy for Wilms tumor exploration of the contralateral kidney has been recommended to detect occult tumors missed on preoperative evaluation. In this review of the National Wilms Tumor Study (NWTS) 4 cases of bilateral Wilms tumors (BWT) we evaluate incidence and outcome of missed bilateral lesions. Materials and Methods:: NWTS-4 enrolled 3,335 patients from August 1986 through September 1994. There were 188 patients with BWT or 5.6% of the total registered. The operative records, pathology and imaging reports were reviewed. Results:: In 11 cases synchronous BWT was diagnosed at surgical exploration, which represents 5.9% of the bilateral cases but only 0.3% of all NWTS-4 cases. Two patients did not undergo preoperative imaging and were excluded from analysis. The size of the missed lesions was less than 1 cm in 6 patients and 1 to 2 cm in 3. Computerized tomography was performed in all patients except one who entered early in the study. Management of missed lesions included enucleation in 2 cases, biopsy in 6 and no surgery in 1. No patient underwent irradiation. The postoperative chemotherapy regimen consisted of doxorubicin, dactinomycin and vincristine in 6 children, and dactinomycin and vincristine in 3. Median followup was 9 years. There were no recurrences in any kidney with a missed lesion. All 9 patients were alive and disease-free at last followup. Conclusions:: Routine contralateral renal exploration will identify few occult tumors not detected on preoperative imaging. Omission of routine exploration will not likely affect the outcome or management of newly diagnosed Wilms tumor provided preoperative computerized tomography or magnetic resonance imaging is performed. The outcome in these patients was excellent. [Copyright &y& Elsevier]

Thirty-nine previously treated Hodgkin's disease (HD) patients were immunized with 7-valent pneumococcal conjugate vaccine (7-OMPC) followed by one dose of 23-valent polysaccharide pneumococcal vaccine (23-PS). To determine the priming effect of 7-OMPC vaccine, their antibody responses to six serotypes contained in both vaccines were compared to those of 57 HD patients who received 23-PS vaccine only. The geometric mean antibody concentrations after immunization with 23-PS vaccine were significantly higher for five of the six measured serotypes in HD patients primed with 7-OMPC vaccine compared with responses in HD patients who received 23-PS vaccine only. The mean of the six antibody concentrations was significantly higher for the primed group at 12.5 micrograms/mL and 7.76 micrograms/mL, respectively (P = .015). Priming with a conjugate vaccine should be considered as a strategy to protect high-risk adults. [ABSTRACT FROM AUTHOR]