Evaluation of soft tissue attachments to a novel intra-abdominal prosthetic in a rabbit model.

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.

Repair of esophageal atresia with tracheoesophageal fistula via thoracotomy: a contemporary series.

BACKGROUND: A recent series detailing thoracoscopic repair of esophageal atresia with tracheoesophageal fistula (EA/TEF) reported lower complication rates compared with historic controls. This study provides a contemporary cohort of patients repaired via thoracotomy for comparison with the recent large multi-institutional thoracoscopic series. METHODS: Records of patients with EA/TEF between 1993 and 2008 were reviewed. Attention was focused on demographics and complications including anastomotic leak, recurrent fistulae, stricture formation, and need for fundoplication. RESULTS: Seventy-two patients underwent repair of EA/TEF via thoracotomy. Complication rates in the current series compared with the thoracoscopic series were anastomotic leak, 2.7% versus 7.6%; recurrent fistulae, 2.7% versus 1.9%; stricture, 5.5% versus 3.8%; and need for fundoplication, 12% versus 24%. Differences in complication rates did not reach statistical significance. Two children in this cohort developed mild scoliosis attributed to congenital vertebral anomalies, neither of whom required intervention. CONCLUSIONS: Thoracoscopic repair of EA/TEF yielded complication rates similar to this contemporary series; however, trends toward increased anastomotic leaks and greater need for fundoplication were noted. No musculoskeletal sequelae were directly attributable to thoracotomy.

Laparoscopic approach to adrenalectomy: review of perioperative outcomes in a single center.

Laparoscopic expertise increases the volume of adrenalectomies at referral centers. We report our 10-year experience with laparoscopic adrenalectomy. All laparoscopic adrenalectomies at a single institution were prospectively recorded in a surgical outcomes database. Patient demographics, operative/perioperative outcomes, and adrenal pathology were reviewed retrospectively. From March 1999 through July 2009, 154 laparoscopic adrenalectomies were performed in 150 patients. Average patient age was 49.9 years (range 15-82); mean body mass index was 31.1 kg/m(2) (range 17-56). Pathologic diagnoses included hyperaldosteronism (n = 69), nonfunctional adenoma (n = 28), pheochromocytoma (n = 23), hypercortisolism (n = 14), malignancy (primary n = 3, metastasis n = 9), and cyst (n = 4). Seventy-three per cent (n = 110) occurred on the left, 23 per cent (n = 35) on the right, 2.6 per cent (n = 4) bilateral, and 0.6 per cent (n = 1) as extra-adrenal. The average tumor measured 3.6 cm (range 0.4-12). The average operative time was 156 minutes (range 62-409), the mean estimated blood loss was 60 mL (range 10-400), and mean American Society of Anesthesiologists score was 2.6 (range 1-4). Three operations (0.2%) were converted to open. Three patients (0.2%) experienced perioperative complications (respiratory failure, urinary tract infection, line sepsis, and readmission within 30 days). The average length of stay was 3.4 days (range 1-44) and mean follow-up was 96.9 days (5-2567). No wound-related complications or deaths occurred. Pathologic diagnosis was not associated with a particular side or development of a complication (P > 0.5). Patients with pheochromocytomas had the longest operative times, highest estimated blood loss, and highest American Society of Anesthesiologists scores (218.2 minutes, 128 mL, 3.0; P < 0.004). Laparoscopic adrenalectomy is safe and effective. Removal of pheochromocytomas is more challenging and may be more appropriate for referral to a specialized center for optimal outcomes.

Pushing the envelope in biomaterial research: initial results of prosthetic coating with stem cells in a rat model.

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.

Effect of bacterial exposure on acellular human dermis in a rat ventral hernia model.

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.

Does liver appearance predict histopathologic findings: prospective analysis of routine liver biopsies during bariatric surgery.

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.

Laparoscopic versus open live donor nephrectomy: outcomes analysis of 266 consecutive patients.

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.

Maximizing the donor pool: use of right kidneys and kidneys with multiple arteries for live donor transplantation.

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.

Probiotic acidified formula in an animal model reduces pulmonary and gastric bacterial load.

BACKGROUND/PURPOSE: We previously reported that a diet acidified with citric acid effectively reinforces gastric acid protection against bacterial colonization and translocation. In this study, our objective was to examine a biologically acidified formula hypothesized to be more physiologic than formula acidified with free acid. This study was Institutional Animal Care and Use Committee (IACUC) approved and designed to determine whether this diet is better tolerated and equally effective to acidification with citric acid against gut colonization and subsequent bacterial translocation in a premature infant rabbit model. METHODS: A total of 89 rabbit pups born via cesarean delivery 1 day preterm were randomly assigned to 3 feeding groups: Pelargon Nestle at pH 4.55; NAN Nestle, a control diet at pH 7.0 with similar composition; and NAN Nestle acidified in the laboratory with citric acid at pH 4.55. Pups were gavage fed every 12 hours with Enterobacter cloacae challenges of 10 colony-forming units per milliliter of diet per feed and killed on day 3 of life. Lungs, liver, spleen, mesenteric lymph nodes, stomach, and cecum were cultured and quantitatively analyzed for target organism growth and statistically analyzed using chi(2) and Kruskal-Wallis tests. RESULTS: Pelargon, compared to acidified NAN and NAN, significantly reduced the incidence of gastric colonization (15/33 [45%], 21/27 [78%], and 25/29 [86%], respectively; P < .01) and pulmonary colonization (10/33 [30%], 19/27 [70%], 21/29 [72%]; P < .01). Comparing the bacterial logs of colonized groups, the same benefit is observed in the lungs (0.77 +/- 1.22, 1.89 +/- 1.41, 2.12 +/- 1.47; P < .01). Gut colonization and bacterial translocation were equivalent between treatment groups (mesenteric lymph nodes: 10/33 [30%], 11/27 [40%], 8/29 [27%]; spleen: 10/33 [30%], 7/27 [26%], 8/29 [27%]; liver: 10/33 [30%], 6/27 [22%], 9/29 [31%]; cecum: 33/33 [100%], 27/27 [100%], 29/29 [100%]). CONCLUSION: Biologically acidified formula demonstrated superior protection against pulmonary and gastric colonization compared to normal pH and diets acidified with free acid. Its effects may potentially reduce clinical pulmonary infection.

Combined open and laparoscopic approach to chronic pain after inguinal hernia repair.

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.

Formula fortified with live probiotic culture reduces pulmonary and gastrointestinal bacterial colonization and translocation in a newborn animal model.

BACKGROUND/PURPOSE: Acidified diets are protective against intestinal bacterial colonization and translocation. Probiotic diets are designed to modulate the intestinal flora to enhance mucosal immunity. This study was designed to determine if formula acidified with live probiotic decreases bacterial gut colonization and translocation, and is equally tolerated as other acidified diets. METHODS: One hundred twenty-eight rabbit pups delivered via cesarean section [cesarean delivery, cesarean birth, abdominal delivery] were randomly assigned to 4 feeding groups: NAN Nestle (control, pH 7.0), NAN acidified with citric acid (pH 4.55), biologically acidified Pelargon (pH 4.55), and NAN with live Lactococcus lactis culture (pH 4.2). Pups were gavage fed every 12 hours with Enterobacter cloacae challenges of 10 colony-forming units/mL per feed and killed on day of life 3. Lungs, liver, spleen, mesenteric lymph nodes (MLNs), stomach, and cecum were cultured and quantitatively analyzed for target organism growth. Results were analyzed using chi(2) tests. RESULTS: NAN with live probiotic culture, when compared with Pelargon, acidified NAN, and NAN, significantly reduced the incidence of Enterobacter pulmonary colonization (P < .01), bacterial translocation (liver, P < .025; spleen and MLN, P < .05), and gastric and intestinal colonization (P < .001 for both). CONCLUSION: Probiotic-fortified formula provides superior protection against pulmonary and gastrointestinal bacterial colonization and translocation compared with neutral and acidified formulas, and is equally tolerated.

Duodenal- jejunal bypass sleeve: a totally endoscopic device for the treatment of morbid obesity.

Morbid obesity affects over 15 million people in the United States. Nonsurgical management produces sustained weight loss in less than 5% of patients. Despite associated comorbidities, less than 1% of obese patients seek surgical intervention. Less invasive procedures have been developed with varying success. The Endobarrier( trade mark) (GI Dynamics(trade mark), Watertown, MA) duodenal-jejunal bypass sleeve is a totally endoscopically delivered device designed to produce weight loss in the morbidly obese. We describe the first placement of a duodenal-jejunal bypass sleeve in a patient in the United States. A blinded, randomized, prospective clinical trial was approved by the Food and Drug Administration to evaluate safety and efficacy of a novel device for weight loss in the obese. The first patient enrolled was a 36-year-old woman with body mass index of 45.2. After informed consent, endoscopic placement of the device under general anesthesia was performed using fluoroscopy to confirm positioning. The device was placed without complications. At conclusion of the 3-month study period, the device was removed endoscopically. Total weight lost by the patient was 9.09 kg. Described herein is the first deployment of the duodenal-jejunal bypass sleeve in North America. The device is delivered in a totally endoscopic manner in morbidly obese patients. In our patient, total weight loss at 3 months was 9.09 kg. Continued follow-up and enrollment is ongoing to demonstrate patient safety and efficacy. Additional studies are being performed to elucidate mechanism of weight loss and future clinical applications of this device.

Surgical management of lipoblastoma.

BACKGROUND/PURPOSE: Lipoblastoma/lipoblastomatosis, a rare benign pediatric tumor composed of embryonic fat, most often presents as a rapidly growing mass in children younger than 3 years. This benign tumor locally recurs up to 25% of the time. This retrospective review was done to emphasize problems with diagnosis, management, and the approach to follow-up care. METHODS: Sixteen cases of pathologically proven lipoblastoma presenting to a single institution over a 16-year period (1988-2004) were reviewed retrospectively for clinical features and outcome. RESULTS: There were 11 males and 5 females ranging in age from 18 days to 12.75 years. Preoperative diagnoses were accurate in only 3 cases. Two lesions recurred locally over a period of 10 months and 5 years. One lesion presented with local infiltration. Six lesions were right-sided, 5 were left-sided, and 5 were midline. CONCLUSIONS: It is important to consider lipoblastoma in the diagnosis of a rapidly enlarging fatty mass in children. Complete resection is the only definitive treatment and should not be delayed when impingement on surrounding structures is imminent. There is a tendency for these lesions to recur despite presumed complete excision. Therefore, follow-up for a minimum of 5 years is recommended.

Enoxaparin inhibits fibrin sheath formation and decreases central venous catheter colonization following bacteremic challenge.

OBJECTIVE: Inhibition of fibrin sheath formation by enoxaparin decreases catheter colonization. Fibrin-binding radioactive tracer and catheter weights quantify fibrin reduction. DESIGN: Controlled experimental study of central venous line colonization. SETTING: Animal laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: Central venous lines were introduced into right external jugular veins of 254 animals in three groups: enoxaparin, Fibrimage, and catheter weight. The enoxaparin group (n = 196) received daily enoxaparin injections (n = 97) or catheter implantation only (n = 99); 176 received tail vein injections of Staphylococcus epidermidis on postoperative day (POD) 10. Twenty rats received saline injections as a control. On POD 13, catheters were removed and incubated in broth at 37 degrees C for 48 hrs. Turbid samples were plated. In the Fibrimage group (n = 39), 20 rats receiving enoxaparin were compared with 19 controls without enoxaparin; all received S. epidermidis injections on POD 10. Fibrimage, fibrin-binding radiolabeled tracer, was given 1 hr before catheter removal. In the weight group (n = 19), six rats received enoxaparin; 13 did not. All received injections of S. epidermidis on POD 10. MEASUREMENTS AND MAIN RESULTS: Positive plates underwent analytic profile index testing, ensuring correlation with inoculum. Results were compared using Fisher's exact or chi-square tests. Gamma counts were determined in the Fibrimage group. Catheter tip weights were recorded. Results from the Fibrimage and weight groups were compared using Student's t-test. The enoxaparin group had fewer catheters colonized (17 of 77) vs. no enoxaparin (42 of 99; p < .01). Pericatheter sheaths contained less fibrin compared with controls. Fibrimage group gamma counts were significantly decreased for the enoxaparin subgroup (x = 2244 counts per minute) vs. controls (x = 3767 counts per minute; p < .0002). The weight of catheter tips treated with enoxaparin (x = 39 mg) vs. controls (x = 90 mg) was also significantly decreased (p < .0001). CONCLUSIONS: Enoxaparin decreases the amount of fibrin surrounding central venous catheters. The incidence of catheter colonization decreases when the amount of fibrin within the pericatheter sheath decreases.

Air-gun injuries: initial evaluation and resultant morbidity.

Severity of injuries from air-powered weapons can be underappreciated. Transformation of these weapons into toys makes them available to children. Our experience reveals the underestimated injury severity and emphasizes need for prompt trauma evaluation. Retrospective chart review of children sustaining air-gun injuries and evaluated at a single, pediatric hospital from 1991 to 2002 was performed. Medical record numbers were retrieved from a trauma data base. Data included age, weapon type, firing distance, injury site, radiographic studies, operative intervention, length of stay, and long-term disability. Ocular injuries were excluded secondary to known severity. All other injuries and treatments are described. Thirty-four children, average age 10 years +/- 3.3 years, sustained 35 injuries from 1991 through 2002. Twenty-one children required admission, 19 children required surgery, and 5 children experienced long-term disability. Average time to definitive care was 3 hours 12 minutes. Sites of injury included head, neck, chest, abdomen, and extremities. Average hospital stay was 4.3 days. In the pediatric population, air-gun injuries can be underestimated. Lack of collateral tissue damage makes wounds appear innocuous to unsuspecting medical personnel resulting in delayed care. During initial evaluation, injuries from air guns deserve the same respect as those caused by conventional firearms.