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BACKGROUND: Laparoscopic ventral hernia repair requires placement of an intraperitoneal prosthetic. Composite mesh types have been developed to address the shortcomings of standard meshes. The authors evaluated the host reaction to intraperitoneal placement of a novel composite material. MATERIALS AND METHODS: A comparison of an innovative polypropylene/polylactide composite mesh was made to parietex composite (PCO), Proceed, and DualMesh. Eighteen meshes per group were implanted on intact peritoneum in New Zealand white rabbits. The main outcome measures included the formation of visceral adhesions, adhesion tenacity, tensiometric measurements, and histological analysis. Evaluations of adhesions were made at 1, 4, and 16 weeks using a 2-mm minilaparoscopy. RESULTS: There were no significant differences in the mean adhesion scores between the composite mesh types at week 1 (P = .15) and week 16 (P = .06). At 4 weeks, PCO had significantly fewer adhesions when compared with the other 3 mesh types (P = .02). Adhesion tenacity was also equivalent within the group at 16 weeks (P = .06). Tensiometry and histological analysis revealed no statistically significant differences between the mesh types. CONCLUSIONS: Four different composite mesh types had equivalent intra-abdominal soft tissue attachments in a rabbit model after a 16-week implantation period. PCO demonstrated the lowest mean adhesion score of each mesh type. Each mesh exhibited equivalent stiffness and energy to failure after explantation. The 4 composite mesh types demonstrated the successful formation of a neoperitoneum and comparable host biocompatibility as evidenced by similar degrees of inflammation.

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Robotic thyroidectomy has been recently introduced as a new modality of treatment for selected benign and malignant thyroid lesions. The standard technique, popularized by a leading Korean group, combines an axillary and a thoracic approach to accomplish thyroid resection without neck incision. We recently introduced a modified technique that has enabled us to complete robotic thyroidectomy through a single axillary incision. We herein report our initial successful experience in 35 cases with the modified technique.

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Reverse alignment (mirror image) visualization is a disconcerting situation occasionally faced during laparoscopic operations. This occurs when the camera faces back at the surgeon in the opposite direction from which the surgeon's body and instruments are facing. Most surgeons will attempt to optimize trocar and camera placement to avoid this situation. The authors' objective was to determine whether the intentional use of reverse alignment visualization during laparoscopic training would improve performance. A standard box trainer was configured for reverse alignment, and 34 medical students and junior surgical residents were randomized to train with either forward alignment (DIRECT) or reverse alignment (MIRROR) visualization. Enrollees were tested on both modalities before and after a 4-week structured training program specific to their modality. Student's t test was used to determine differences in task performance between the 2 groups. Twenty-one participants completed the study (10 DIRECT, 11 MIRROR). There were no significant differences in performance time between DIRECT or MIRROR participants during forward or reverse alignment initial testing. At final testing, DIRECT participants had improved times only in forward alignment performance; they demonstrated no significant improvement in reverse alignment performance. MIRROR participants had significant time improvement in both forward and reverse alignment performance at final testing. Reverse alignment imaging for laparoscopic training improves task performance for both reverse alignment and forward alignment tasks. This may be translated into improved performance in the operating room when faced with reverse alignment situations. Minimal lab training can account for drastic adaptation to this environment.

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BACKGROUND: Coating prosthetic for hernia repair with a patient's own cells could improve biocompatibility by decreasing inflammation and adhesion formation and by increasing tissue ingrowth and resistance to infection. The objective of this study was to prove the feasibility of prosthetic coating with stem cells and to assess its resistance to adhesion formation when implanted in an animal model. METHODS: Adult Lewis rat bone marrow stem cells were harvested and cultured. Stem cells were then implanted on three different prosthetics. The prosthetic with the best stem cell adherence was implanted intraperitoneally into six adult rats. Untreated prosthetic was implanted in control animals (n = 12). After 2 weeks, intra-abdominal adhesions were graded using an adhesion scoring scale by two surgeons who were blinded to the animal group. Data were analyzed using the Wilcoxon rank-sum test. RESULTS: Stem cells demonstrated the best adherence and growth on polyglactin prosthetics. After implantation, the stem cell-coated polyglactin prosthetic had <25% of its surface area covered with adhesions in five (83%) samples, whereas the control polyglactin group had only one sample (8.3%) with <25% adhesions, and seven of its samples (58.3%) had >50% surface area adhesions (p < 0.05). CONCLUSIONS: The feasibility of hernia prosthetic coating with stem cells was demonstrated. Furthermore, stem-cell coated polyglactin prosthetic exhibited improved biocompatibility by decreasing adhesion formation in an animal model. Further study is needed to determine the factors that promote stem cell adherence to prosthetics and the in vivo prosthetic biomechanics after stem cell coating. This work is underway in our laboratory.

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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.

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INTRODUCTION: Intraluminal staplers for gastrojejunostomy construction during Roux-en-Y gastric bypass (RYGBP) may be associated with postoperative strictures. We analyzed outcomes of a transabdominal circular-stapled RYGBP with evaluation of short- and long-term anastomotic complications. METHODS: All laparoscopic RYGBPs performed between January 2004 and December 2005 at an academic institution were reviewed. The gastrojejunostomy was created by using the transabdominal passage of a 21-mm intraluminal circular stapler into an antecolic, antegastric Roux limb. This retrospective chart review analyzes patient demographics, anastomotic complications, and weight loss. RESULTS: Between January 2004 and December 2005, 159 patients underwent transabdominal circular-stapled RYGBP. Fifteen patients developed a stenosis at the gastrojejunostomy, all requiring endoscopic balloon dilatation. One of these patients required laparoscopic revision of the gastrojejunostomy. Eleven strictures occurred after 30 days, whereas only 4 strictures occurred within 30 days of surgery. Two marginal ulcerations were seen within 1 year of surgery. CONCLUSION: Our 9.4% stricture rate parallels what has been reported in the literature. The majority of strictures were amenable to one endoscopic treatment session. Transabdominal circular-stapled gastrojejunostomy is a reproducible construct for use in bariatric surgery.

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BACKGROUND: Nonalcoholic fatty liver disease is associated with morbid obesity. Liver biopsy is the reference standard for the diagnosis of nonalcoholic fatty liver disease. It is unclear whether the macroscopic liver appearance correlates with the histopathologic findings. Our objective was to determine the relationship between the intraoperative liver appearance and the histopathologic findings during laparoscopic bariatric surgery at a tertiary medical center. METHODS: Data were prospectively collected from 108 consecutive patients undergoing laparoscopic bariatric surgery with routine intraoperative liver biopsy. An intraoperative liver visual score was recorded according to the size, tan-speckling, and contour. The liver histologic findings were categorized into 3 groups: (1) normal; (2) bland steatosis; and (3) nonalcoholic steatohepatitis (NASH). The liver visual score was compared with the liver histologic findings. A recorded video of the liver was regraded at a later date to determine observer agreement. RESULTS: The prevalence of NASH was 23% (n = 25). Of the 108 patients, 48% with NASH had normal-appearing livers and accounted for 24% (n = 12) of the 50 normal-appearing livers. A similar proportion of NASH cases was found in all 3 visual categories. Furthermore, no relationship was found between the number of abnormal visual cues and the liver histologic findings (P = .23). No complications were directly attributable to liver biopsy. The kappa values for intraobserver and interobserver agreement ranged from fair to almost perfect. CONCLUSION: NASH is common in the morbidly obese population. There does not appear to be a relationship between liver appearance and the histopathologic findings. Intraoperative liver biopsy is a safe and accurate method of diagnosing liver disease and should be considered in all morbidly obese patients undergoing abdominal surgery.

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BACKGROUND: Minimally invasive surgical techniques have become the preferred method for live donor nephrectomy (DN) in many centers. We compared our experience with laparoscopic and open DN in a single institution. METHODS: Data for 266 consecutive live DNs were collected. Demographic, intraoperative, and postoperative data were compared. RESULTS: A total of 199 hand-assisted laparoscopic (HAL) DNs, 18 totally laparoscopic (TL), and 49 open DNs were performed. Laparoscopic DN was associated with a shorter operative time (p < 0.013), less blood loss (p < 0.0001), and shorter hospital stay (p < 0.0001) than open DN. Warm ischemia time was less for HAL versus TL DN (59.9 vs. 90.0 seconds; p < 0.0001). Compared with open DN, laparoscopic patients had fewer complications (p < 0.03), fewer wound infections (p < 0.004), less wound paresthesias (p < 0.0009), and fewer complaints of chronic incisional pain (p < 0.0001). Delayed graft function during the first 24 h postoperatively was significantly less for the laparoscopic DN versus the open cases (12.9% vs. 30.4%; p = 0.003), but the need for hemodialysis for the recipient was similar between groups (6.9% vs. 5%; p = not significant). CONCLUSIONS: Laparoscopic DN resulted in less blood loss, reduced operative time, and shorter hospital stay than open DN. Hand-assisted laparoscopic DN has the potential to decrease warm ischemia time for renal allografts. Donors managed laparoscopically had fewer complications, significantly less wound-related morbidity, and less delayed graft function than patients who underwent open DN.

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BACKGROUND: Studies have shown donor and recipient outcomes to be equivalent for laparoscopic donor nephrectomy (LDN) and open donor nephrectomy. In the past, LDN has been avoided in the procurement of the right kidney or organs with multiple arteries. This study compares procurement of right and left kidneys as well as procurement of single- and multiple artery organs. METHODS: A review of all LDNs at a single institution between August 2000 and December 2007 was performed. The data included estimated blood loss (EBL), need for transfusion, operative time, warm ischemia time, length of hospital stay (LOS), and delayed graft function. Arterial supply was assessed using renal arteriogram or computed tomographic (CT) angiography. Outcomes for multiple versus single artery and left versus right LDN were compared. Student's t-test and chi-square test were used for statistical comparison. RESULTS: A total of 230 LDNs were performed. Multiple arteries were present in 37 donors. The right kidney was procured from 36 donors. No significant difference in EBL, transfusions, operative time, or LOS was noted between multiple and single or right and left LDNs. Warm ischemia time was significantly longer for multiple arteries (mean, 83 s) than for single arteries (mean, 63 s; p = 0.007), and for right kidneys (mean, 86 s) than for left kidneys (mean, 62 s; p = 0.001). No significant difference in delayed graft function was seen in the comparison of multiple (21.6%) and single (11.4%) artery organs (p = 0.11) or of right (13.9%) and left (12.9%) kidneys (p = 0.79). CONCLUSIONS: The presence of multiple arteries or the need to procure the right kidney does not affect the operative outcome of laparoscopic donor nephrectomy. Warm ischemia time may be greater for these groups, but this does not result in delayed allograft function. The laparoscopic approach should be the standard of care even when expansion of the donor pool includes organs with multiple arteries and procurement of the right kidney.

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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.

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BACKGROUND: Poor results for dual-phase parathyroid scintigraphy have recently prompted increased use of dual-tracer imaging. We noticed that seminal studies used higher radiochemical purity than provided by current commercial preparations meeting US Pharmacopea (USP) specifications (90% of technetium bound to sestamibi). We surmised that the presence of unbound Tc (non-MIBI tracer) might hamper dual-phase detection that is dependent on rapid wash-out of technetium from thyroid tissue. PURPOSE: To test the hypothesis that reducing non-MIBI tracer will enhance thyroid wash-out and improve sensitivity of dual-phase imaging. METHODS: Starting in April 2003 we decreased the technetium to sestamibi ratio. This resulted in a significant decrease of non-MIBI tracer from 8.1+/-2.2% (SD) (group 1, n = 42) to 3.5+/-1.1% (group 2, n = 47) (P < 0.05 t-test). We performed a retrospective review of 89 patients with primary hyperparathyroidism who underwent imaging and subsequent surgery. The pathological findings served as the 'gold standard'. RESULTS: Scanning detected 21/39 diseased glands (sensitivity=54%) in group 1 patients. In group 2 imaging detected 38/45 diseased glands (sensitivity = 84%). An improvement in sensitivity (P < 0.01) was achieved by modifying the radiopharmaceutical preparation. CONCLUSIONS: Elevated levels of non-MIBI tracer in Tc-MIBI commercial preparations result in persistent thyroid background activity that may interfere with detection of parathyroid pathology. Achieving a higher degree of radiochemical purity (at least 95% bound, 5% impurities) than required by USP may be needed for optimal results. The large variation in sensitivity reported in the literature may be related in part to non-uniform radiopharmaceutical preparation.

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