Laparoscopic splenectomy for splenic masses.

BACKGROUND: This study aimed to evaluate the perioperative outcomes and pathology of patients undergoing laparoscopic splenectomy for splenic masses. METHODS: The records for 174 patients who underwent laparoscopic splenectomy from May 1994 to August 2006 were reviewed. Patient demographics, preoperative imaging, American Society of Anesthesiologists (ASA) score, body mass index (BMI), estimated blood loss (EBL), operative time, spleen size, complications, hospital length of stay (LOS), pathology, and mortality were extracted from the records. Data are expressed as means +/- standard deviation. Statistical significance (p < 0.05) was determined using a two-tailed t-test and Fisher's exact test. RESULTS: A splenic mass was diagnosed preoperatively for 18 patients (10.3%) (7 males and 11 females). The mean patient age was 51.4 +/- 13.7 years. The mean ASA was 2.3 +/- 0.8, and the mean BMI was 27.3 +/- 5.8 kg/m(2). Computed tomography scans demonstrated splenic masses in all the patients. The mean mass size was 4.3 +/- 3.3 cm (range, 1.0-11.0 cm), and the mean spleen length was 14.6 +/- 7.5 cm (range, 5.5-40.2 cm). Total laparoscopic splenectomy was completed for 15 patients, and hand-assisted splenectomy was performed for 3 patients (2 converted). The mean operative time was 128.3 +/- 38.5 min, and the mean EBL was 110 +/- 137.5 ml. There were no intraoperative complications or 30-day mortalities. The postoperative complication rate was 11.1%, and the mean LOS was 1.9 +/- 1.0 days. The pathology for six patients (33.3%) was malignant (5 lymphomas and 1 adenocarcinoma). There were three false-positive positron emission tomography (PET) scans. Compared with 73 patients undergoing laparoscopic splenectomy for idiopathic thrombocytopenic purpura, there was no significant difference in mean EBL, operative time, conversion rate, complication rate, LOS, or 30-day mortality rate (p > 0.05). CONCLUSIONS: Laparoscopic splenectomy is appropriate for patients whose indication for surgery is splenic mass. Suspicious splenic masses should be removed due to the relatively high incidence of malignant pathology, most commonly lymphoma.

Evaluation of acellular human dermis reinforcement of the crural closure in patients with difficult hiatal hernias.

BACKGROUND: Biologic prosthetics may circumvent mesh-related complications at the esophageal hiatus by becoming remodeled by native cells. We present our experience with acellular human dermal matrix in the repair of difficult hiatal hernias (HH). METHODS: Records of 17 patients who underwent laparoscopic HH repair using acellular human dermis to buttress the crural closure were analyzed. Hernias were paraesophageal (PEH) in 12 patients, large type 1 in 1 patient, and recurrent after prior HH repair in 4 patients. Barium swallow (BAS) was obtained 6-12 months after surgery. (Data are presented as mean +/- standard deviation.) RESULTS: Mean patient age was 65 +/- 12 years and BMI was 31 +/- 4. Mean gastroesophageal (GE) junction distance above the diaphragm in the PEHs was 4.9 +/- 1.5 cm; 9 of 12 patients with PEH had more than 50% of the stomach in the chest. Mean operating time was 273 +/- 48 min. Average hiatal defect size was 4.7 x 2.7 cm, with 4.2 +/- 1.2 sutures used to close the crura. Nissen fundoplication was performed in all patients, esophageal lengthening in four patients, and anterior gastropexy in three patients. Mean hospital length of stay (LOS) was 2.3 +/- 0.8 days. Mean followup was 14.4 +/- 4.4 months. Postoperatively, only one (6%) patient had heartburn/regurgitation, one (6%) had mild dysphagia, and two (12%) take proton pump inhibitors. Followup BAS at 10.3 +/- 4.9 months after surgery showed small recurrent hernias in two patients (12%), but only one was symptomatic. In addition, there was one symptomatic failure of a redo Nissen in an obese patient. Reoperative gastric bypass 15 months later showed an intact crural closure with a remodeled buttress site. CONCLUSIONS: Acellular human dermal matrix may be an effective method to buttress the crural closure in patients with large hiatal hernias. Longer followup in larger numbers of patients is needed to assess the validity of this approach.

Outcomes analysis of laparoscopic resection of pancreatic neoplasms.

BACKGROUND: Experience with laparoscopic resection of pancreatic neoplasms remains limited. The purpose of this study is to critically analyze the indications for and outcomes after laparoscopic resection of pancreatic neoplasms. METHODS: The medical records of all patients undergoing laparoscopic resection of pancreatic neoplasms from July 2000 to February 2006 were reviewed. Data are expressed as mean +/- standard deviation. RESULTS: Laparoscopic pancreatic resection was performed in 22 patients (M:F, 8:14) with a mean age of 56.3 +/- 15.1 years and mean body mass index (BMI) of 26.3 +/- 4.5 kg/m2. Nine patients had undergone previous intra-abdominal surgery. Indications for pancreatic resection were cyst (1), glucagonoma (1), gastrinoma (2), insulinoma (3), metastatic tumor (2), IPMT (4), nonfunctioning neuroendocrine tumor (3), and mucinous/serous cystadenoma (6). Mean tumor size was 2.4 +/- 1.6 cm. Laparoscopic distal pancreatectomy was attempted in 18 patients and completed in 17, and enucleation was performed in 4 patients. Laparoscopic ultrasound (n = 10) and a hand-assisted technique (n = 4) were utilized selectively. Mean operative time was 236 +/- 60 min and mean blood loss was 244 +/- 516 ml. There was one conversion to an open procedure because of bleeding from the splenic vein. The mean postoperative LOS was 4.5 +/- 2.0 days. Seven patients experienced a total of ten postoperative complications, including a urinary tract infection (UTI) (1), lower-extremity deep venous thrombosis (DVT) and pulmonary embolus (1), infected peripancreatic fluid collection (1), pancreatic pseudocyst (1), and pancreatic fistula (6). Five pancreatic fistulas were managed by percutaneous drainage. The reoperation rate was 4.5% and the overall pancreatic-related complication rate was 36.4%. One patient developed pancreatitis and a pseudocyst 5 months postoperatively, which was managed successfully with a pancreatic duct stent. There was no 30-day mortality. CONCLUSIONS: Laparoscopic pancreatic resection is safe and feasible in selected patients with pancreatic neoplasms. With a pancreatic duct leak rate of 27%, this problem remains an area of development for the minimally invasive technique.

Remodeling characteristics and biomechanical properties of a crosslinked versus a non-crosslinked porcine dermis scaffolds in a porcine model of ventral hernia repair.

PURPOSE: The objective of this study was to evaluate the histologic remodeling profile and biomechanical properties of the porcine abdominal wall after repair with HDMI-crosslinked (Permacol(®)) or non-crosslinked (Strattice(®)) porcine dermis in a porcine model of ventral hernia repair. METHODS: Bilateral incisional hernias were created in Yucatan minipigs and repaired after 21 days. The repair site, including mesh and abdominal wall, was harvested after 1, 6, and 12 months and subjected to histologic analysis and uniaxial testing. Native abdominal wall without mesh was also subjected to uniaxial tensile testing. RESULTS: Permacol(®) demonstrated significant improvement over time in every remodeling category except scaffold degradation, while remodeling characteristics of Strattice(®) remained relatively unchanged over time for every category except fibrous encapsulation and neovascularization. However, remodeling scores for Strattice(®) were already significantly higher after just 1 month compared to Permacol(®) in the categories of cellular infiltration, ECM deposition, and neovascularization, providing evidence of earlier remodeling of the non-crosslinked grafts compared to the crosslinked grafts. The tensile strength and stiffness of both crosslinked and non-crosslinked graft-tissue composites were greater than the tensile strength and stiffness of the native porcine abdominal wall in the very early post-operative period (1 month), but there was no difference in tensile strength or stiffness by the end of the study period (12 months). CONCLUSIONS: HDMI collagen crosslinking of porcine dermis scaffolds reduces the early histologic remodeling profile but does not significantly impact the tensile strength or stiffness of the graft-tissue composites in a porcine model of ventral hernia repair.

Pancreatic islet cell tumor metastasis in multiple endocrine neoplasia type 1: correlation with primary tumor size.

BACKGROUND: Islet cell tumor (ICT) metastasis is one of the potentially lethal outcomes of multiple endocrine neoplasia type 1 (MEN 1). Management of ICT in patients with MEN 1 is controversial; some advocate resection based on biochemical evidence of progression, whereas others use tumor size to predict the risk of metastasis and the need for resection. This study correlates the size of primary ICT with the presence of metastases. METHODS: Forty-eight patients with MEN 1 with ICT, from 34 kindreds followed up in our multiple endocrine neoplasia program, were evaluated; 43 of the 48 have been explored for ICT. Metastases to the lymph nodes and liver were documented. RESULTS: Thirty-three percent of patients with pancreatic tumors less than 1 cm in greatest diameter had metastatic disease at surgery and in follow-up, whereas 34.8% of patients with tumors greater than 2 cm in diameter had metastases to lymph nodes or liver. The 2 patients with liver metastases each had primary tumors greater than 2 cm. Follow-up revealed subsequent metastasis in 1 patient. CONCLUSIONS: The size of primary tumors in MEN 1 does not correlate with metastatic potential. This is not a good criterion for exploration. Continued follow-up of these patients will be necessary to define the effect of operation on the course of ICT in MEN 1.

Pancreatic polypeptide is a useful plasma marker for radiographically evident pancreatic islet cell tumors in patients with multiple endocrine neoplasia type 1.

BACKGROUND: The usefulness of human pancreatic polypeptide (hPP) as a plasma marker for islet cell neoplasms is controversial. We sought to determine the relation between fasting plasma hPP levels and radiographically detectable pancreatic islet cell tumors in patients with multiple endocrine neoplasia type 1 (MEN 1). METHODS: Fasting plasma hPP levels were measured prospectively in 202 individuals from 31 independent kindreds with MEN 1. Plasma levels greater than 3.0 times the normal age-specific values were defined as elevated. Patients with elevated plasma hPP levels were evaluated with computed tomographic scanning and magnetic resonance imaging, octreotide scanning, or selective angiography. RESULTS: Twenty-two patients had elevated fasting plasma hPP levels, and 20 of these patients were evaluated radiographically. Pancreatic lesions were detected in 19 patients. A group of eight patients with normal basal fasting plasma hPP levels were evaluated with computed tomography, magnetic resonance imaging, octreotide scanning, or selective angiography based on clinical presentation. One patient in this group had an imaging study that was positive for a pancreatic lesion. CONCLUSIONS: The presence of a markedly elevated fasting plasma hPP level in patients with MEN 1 is 95% sensitive and 88% specific for the presence of radiographically detectable pancreatic islet cell tumors.

Obesity does not adversely affect the outcome of laparoscopic antireflux surgery (LARS).

BACKGROUND: Because it has been suggested that obesity adversely affects the outcome of LARS, it is unclear how surgeons should counsel obese patients referred for antireflux surgery. METHODS: A prospective database of patients undergoing LARS from 1992 to 2001 was used to compare obese and nonobese patients. Patients were surveyed preoperatively and annually thereafter. Questionnaires were completed regarding global symptoms and overall satisfaction. RESULTS: Of the 505 patients, the body mass index (BMI) was <25 (normal) in 16%, 25-29 (overweight) in 42%, and >30 (obese) in 42%. Although the operative time was longer in the obese group than in the normal weight group (137 +/- 55 min vs 115 +/- 42 min, p = 0.003), the time to discharge and rate of complications did not differ. At a mean follow-up of 35 +/- 25 months, there were no differences in symptoms, overall improvement, or patient satisfaction. Further, the rates of anatomic failure were similar among the obese, overweight, and normal weight groups. CONCLUSIONS: Although the operative time is longer in the obese, complication and anatomic failure rates are similar to those in the nonobese at long-term follow-up. Obese patients have equivalent symptom relief and are equally satisfied postoperatively. Therefore, obesity should not be a contraindication to LARS.

Results of laparoscopic Heller-Toupet operation for achalasia.

BACKGROUND: Laparoscopic myotomy has become the preferred treatment for achalasia. Controversy persists on the need for fundoplication and/or its type; when used, most series have utilized the Dor fundoplication. We report a large series of laparoscopic Heller-Toupet procedures. METHODS: All patients operated for achalasia were entered into a prospective database. Pre and postoperative esophageal symptoms, satisfaction scores, and SF-36 variables were compared. Surgical failures were defined as recurrent or persistent dysphagia leading to secondary treatment. Data are expressed as mean +/- S.D. RESULTS: One hundred consecutive cases were analyzed (61 men, 39 women, age 47 +/- 17 yr). Heller-Toupet was performed in 94, whereas six patients had a Dor fundoplication because of mucosal perforation (three) or technical difficulties performing a posterior wrap (three). Operative time was 148 +/- 21 min. There were 13 intraoperative adverse events managed laparoscopically, and no conversions. Minor postoperative complications were noted in two cases, whereas there were no major complications or deaths. Mean hospital stay was 1.2 +/- 0.5 days, (range 1-4). Follow-up was complete in 92% at 26 +/- 17 months. Failures leading to further treatment occurred in 4%. All symptom scores were significantly improved (p < 0.0001). Solid dysphagia score went from 6.4 to 1.0 postoperatively; regurgitation score went from 4.5 to 0.2 (combined frequency and severity, range 0-8). Postoperative global esophageal symptoms scale revealed improvement in 97%, and all domains of the SF-36 were improved. CONCLUSIONS: Although the best surgical approach to achalasia is yet to be determined, laparoscopic Heller-Toupet operation in experienced hands is a safe and effective procedure with low rates of morbidity and failure and high patient satisfaction.

Histologic evaluation of absorbable and non-absorbable barrier coated mesh secured to the peritoneum with fibrin sealant in a New Zealand white rabbit model.

PURPOSE: The purpose of this study is to evaluate the histologic response to fibrin sealant (FS) as an alternative fixation method for laparoscopic ventral hernia repair. METHODS: One non-absorbable barrier mesh (Composix™) and three absorbable barrier meshes (Sepramesh™, Proceed™, and Parietex™ Composite) were used for the study, with uncoated macroporous polypropylene mesh (ProLite Ultra™) as the control. Three methods of fixation were used: #0-polypropylene suture + FS (ARTISS™, Baxter Healthcare Corp.), FS alone (ARTISS™), or tacks alone (n = 10 for each group). Two pieces of mesh (of dimensions 4 × 4-cm) were secured intraperitoneally in 75 New Zealand white rabbits. After 8 weeks, hematoxylin and eosin (H&E)-stained specimens were evaluated for host tissue response. Statistical significance (P < 0.05) was determined using a one-way analysis of variance (ANOVA) with Fisher's least significant difference (LSD) post hoc test. RESULTS: Composix™ with FS only showed significantly greater cellular infiltration than with suture + FS (P = 0.0007), Proceed™ with FS only had significantly greater neovascularization than with suture + FS (P = 0.0172), and ProLite Ultra™ with suture + FS had significantly greater neovascularization than with tacks only (P = 0.046). Differences due to mesh type showed that Composix™ exhibited less extensive cellular infiltration (P ≤ 0.0032), extracellular matrix (ECM) deposition, and neovascularization, and demonstrated less inflammatory cells and more fibroblasts compared to the other meshes (P < 0.05). CONCLUSIONS: FS did not have a significant histologic effect compared to tacks when utilized for the fixation of mesh to the peritoneum of New Zealand White rabbits. However, the mesh type did have a significant histologic effect. The permanent barrier mesh (Composix™) was associated with less histologic incorporation than absorbable barrier and macroporous meshes, as evidenced by lower levels of cellular infiltration, ECM deposition, and neovascularization, independent of the fixation method used.

Histologic and biomechanical evaluation of a novel macroporous polytetrafluoroethylene knit mesh compared to lightweight and heavyweight polypropylene mesh in a porcine model of ventral incisional hernia repair.

PURPOSE: To evaluate the biocompatibility of heavyweight polypropylene (HWPP), lightweight polypropylene (LWPP), and monofilament knit polytetrafluoroethylene (mkPTFE) mesh by comparing biomechanics and histologic response at 1, 3, and 5 months in a porcine model of incisional hernia repair. METHODS: Bilateral full-thickness abdominal wall defects measuring 4 cm in length were created in 27 Yucatan minipigs. Twenty-one days after hernia creation, animals underwent bilateral preperitoneal ventral hernia repair with 8 × 10 cm pieces of mesh. Repairs were randomized to Bard(®)Mesh (HWPP, Bard/Davol, http://www.davol.com), ULTRAPRO(®) (LWPP, Ethicon, http://www.ethicon.com), and GORE(®)INFINIT Mesh (mkPTFE, Gore & Associates, http://www.gore.com). Nine animals were sacrificed at each timepoint (1, 3, and 5 months). At harvest, a 3 × 4 cm sample of mesh and incorporated tissue was taken from the center of the implant site and subjected to uniaxial tensile testing at a rate of 0.42 mm/s. The maximum force (N) and tensile strength (N/cm) were measured with a tensiometer, and stiffness (N/mm) was calculated from the slope of the force-versus-displacement curve. Adjacent sections of tissue were stained with hematoxylin and eosin (H&E) and analyzed for inflammation, fibrosis, and tissue ingrowth. Data are reported as mean ± SEM. Statistical significance (P < 0.05) was determined using a two-way ANOVA and Bonferroni post-test. RESULTS: No significant difference in maximum force was detected between meshes at any of the time points (P > 0.05 for all comparisons). However, for each mesh type, the maximum strength at 5 months was significantly lower than that at 1 month (P < 0.05). No significant difference in stiffness was detected between the mesh types or between timepoints (P > 0.05 for all comparisons). No significant differences with regard to inflammation, fibrosis, or tissue ingrowth were detected between mesh types at any time point (P > 0.09 for all comparisons). However, over time, inflammation decreased significantly for all mesh types (P < 0.001) and tissue ingrowth reached a slight peak between 1 and 3 months (P = 0.001) but did not significantly change thereafter (P > 0.09). CONCLUSIONS: The maximum tensile strength of mesh in the abdominal wall decreased over time for HWPP, LWPP, and mkPTFE mesh materials alike. This trend may actually reflect inability to adequately grip specimens at later time points rather than any mesh-specific trend. Histologically, inflammation decreased with time (P = 0.000), and tissue ingrowth increased (P = 0.019) for all meshes. No specific trends were observed between the polypropylene meshes and the monofilament knit PTFE, suggesting that this novel construction may be a suitable alternative to existing polypropylene meshes.

Early biocompatibility of crosslinked and non-crosslinked biologic meshes in a porcine model of ventral hernia repair.

PURPOSE: Biologic meshes have unique physical properties as a result of manufacturing techniques such as decellularization, crosslinking, and sterilization. The purpose of this study is to directly compare the biocompatibility profiles of five different biologic meshes, AlloDerm(®) (non-crosslinked human dermal matrix), PeriGuard(®) (crosslinked bovine pericardium), Permacol(®) (crosslinked porcine dermal matrix), Strattice(®) (non-crosslinked porcine dermal matrix), and Veritas(®) (non-crosslinked bovine pericardium), using a porcine model of ventral hernia repair. METHODS: Full-thickness fascial defects were created in 20 Yucatan minipigs and repaired with the retromuscular placement of biologic mesh 3 weeks later. Animals were euthanized at 1 month and the repair sites were subjected to tensile testing and histologic analysis. Samples of unimplanted (de novo) meshes and native porcine abdominal wall were also analyzed for their mechanical properties. RESULTS: There were no significant differences in the biomechanical characteristics between any of the mesh-repaired sites at 1 month postimplantation or between the native porcine abdominal wall without implanted mesh and the mesh-repaired sites (P > 0.05 for all comparisons). Histologically, non-crosslinked materials exhibited greater cellular infiltration, extracellular matrix (ECM) deposition, and neovascularization compared to crosslinked meshes. CONCLUSIONS: While crosslinking differentiates biologic meshes with regard to cellular infiltration, ECM deposition, scaffold degradation, and neovascularization, the integrity and strength of the repair site at 1 month is not significantly impacted by crosslinking or by the de novo strength/stiffness of the mesh.

Evaluation of acute fixation strength of absorbable and nonabsorbable barrier coated mesh secured with fibrin sealant.

INTRODUCTION: The purpose of this study was to evaluate the acute fixation strength of fibrin sealant as an alternative fixation method for laparoscopic ventral hernia repair (LVHR) when utilized with absorbable and nonabsorbable barrier meshes. METHODS: Representative mesh types for LVHR included one nonabsorbable barrier mesh (Bard Composix) and three absorbable barrier meshes (Sepramesh, Proceed, and Parietex Composite Mesh). Macroporous polypropylene mesh (Prolite Ultra) served as a control. An associated pilot study demonstrated that acute fixation was not achieved with C-Qur or Dualmesh, thus these meshes were not subjected to further analysis. Two fibrin sealants varying in thrombin concentration (TISSEEL 500 IU/ml or ARTISS 4 IU/ml) were each utilized to secure a 3 x 4 cm piece of mesh to the peritoneal surface of harvested abdominal wall from New Zealand white rabbits. Ten samples were prepared for each mesh and fibrin sealant combination. The resulting mesh-tissue interface (3 x 3 cm) underwent lap shear testing at a rate of 0.42 mm/s using a tensiometer (Instron 5542, Norwood, MA). The maximum load sustained by the construct was recorded as the acute fixation strength in units of Newtons (N). Data are given as means +/- SEM. Statistical significance (P < 0.05) was determined using a two-way ANOVA and Bonferroni post-test. RESULTS: There was no significant difference (P > 0.05) in the acute fixation strength achieved by ARTISS versus TISSEEL with Composix, Sepramesh, Proceed, and Parietex Composite Mesh. However, Prolite Ultra fixed with ARTISS (7.099 +/- 1.01 N) had a significantly higher tensile strength (P < 0.001) than Prolite Ultra fixed with TISSEEL (3.405 +/- 0.72 N). Among meshes fixed with TISSEEL, Parietex Composite (3.936 +/- 0.73 N) was significantly stronger than Sepramesh (1.760 +/- 0.33 N) (P < 0.05). CONCLUSIONS: Acute fixation strength is equivalent for TISSEEL and ARTISS fibrin sealants for selected nonabsorbable (Composix) and absorbable barrier-coated (Sepramesh, Proceed, and Parietex Composite Mesh) meshes. Previous evaluations in this model indicated fibrin sealant alone did not appear to be a suitable method of fixation with C-Qur or DualMesh against the peritoneum. Long-term evaluation is needed to evaluate the efficacy of this method of fixation using absorbable and nonabsorbable barrier-coated meshes in a model of LVHR.

Evaluation of fenestrated and non-fenestrated biologic grafts in a porcine model of mature ventral incisional hernia repair.

INTRODUCTION: The purpose of this study is to compare the tissue incorporation of a novel fenestrated and non-fenestrated crosslinked porcine dermal matrix (CPDM) (CollaMend™, Davol Inc., Warwick, RI) in a porcine model of ventral hernia repair. METHODS: Bilateral abdominal wall defects were created in 12 Yucatan minipigs and repaired with a preperitoneal or intraperitoneal technique 21 days after hernia creation. Animals were randomized to fenestrated or non-fenestrated CPDM for n = 6 pieces of each graft in the preperitoneal or intraperitoneal location. All animals were sacrificed at 1 month. Adhesion characteristics and graft contraction/growth were measured by the Garrard adhesion grading scale and transparent grid overlay. Histological analysis of hematoxylin and eosin (H&E)-stained slides was performed to assess graft incorporation. Tissue incorporation strength was measured by a T-peel tensile test. The strength of explanted CPDM alone and de novo CPDM was measured by a uniaxial tensile test using a tensiometer (Instron, Norwood, MA) at a displacement rate of 0.42 mm/s. Statistical significance (P < 0.05) was determined for histological analysis using a Kruskal-Wallis non-parametric test with a Bonferroni correction, and for all other analyses using a two-way analysis of variance (ANOVA) with a Bonferroni post-test or a Kruskal-Wallis non-parametric test with a Dunn's post-test. RESULTS: Intraperitoneal placement of fenestrated CPDM resulted in a significantly higher area of adhesions and adhesion score compared to the preperitoneal placement of fenestrated CPDM (P < 0.05). For both preperitoneal and intraperitoneal placement, histological findings demonstrated greater incorporation of the graft due to the fenestrations. No significant differences were detected in the uniaxial tensile strengths of the graft materials alone, either due to the graft type (non-fenestrated vs. fenestrated) or due to the placement location (preperitoneal vs. intraperitoneal). The incorporation strength (T-peel force) was significantly greater for fenestrated compared to non-fenestrated CPDM when placed in the preperitoneal location (P < 0.01). The incorporation strength was also significantly greater for fenestrated CPDM placed in the preperitoneal location compared to fenestrated CPDM placed in the intraperitoneal location (P < 0.05). CONCLUSIONS: Fenestrations in CPDM result in greater tissue incorporation strength and lower adhesion area and score when placed in the preperitoneal location. Fenestrations in CPDM allow for greater tissue incorporation without accelerating graft degradation. Fenestrations may be placed in CPDM while still allowing adequate graft strength for intraperitoneal and preperitoneal hernia repairs at 1 month in a porcine model.

Genetic testing and early thyroidectomy for inherited medullary thyroid carcinoma.

The recent identification of mutations in the RET proto-oncogene that are associated with multiple endocrine neoplasia type 2 (MEN 2) syndromes has allowed therapeutic intervention in affected individuals on the basis of direct genetic testing. The principal endocrine neoplasm that occurs in patients with the MEN 2 syndromes is medullary thyroid carcinoma. This thyroid neoplasm is the only consistently malignant feature of the MEN 2 syndromes and it is the most common cause of death in affected patients. Kindred members at risk for one of the MEN 2 syndromes can be studied by direct DNA analysis to determine whether they have inherited a RET mutation. Those with a positive test can be treated by early thyroidectomy and cured when the disease is microscopic and localized to the thyroid gland. Total thyroidectomy is performed as early as 5 years of age and is associated with minimal morbidity and virtually no mortality. Residual or persistent medullary thyroid carcinoma following thyroidectomy can best be determined by detecting increased levels of calcitonin following the administration of intravenous calcium gluconate and pentagastrin.

Lethality of multiple endocrine neoplasia type I.

The lethality of the endocrine tumors associated with multiple endocrine neoplasia type I (MEN-I), particularly the pancreatic islet cell tumors, has been controversial. We evaluated the cause and age of death in MEN-I kindreds. Our database contains 34 distinct kindreds with 1838 members. Reliable death data are available for 103 people (excluding accidents and age < 18 years). We compared survival curves of MEN-I patients who died from causes related to MEN-I with those from MEN-I carriers who died from a nonendocrine cause and unaffected kindred members. We also compared ages of death between affected and unaffected members of MEN-I kindreds. Of 59 MEN-I-affected patients, 27 died directly of MEN-I-specific illness and 32 of non-MEN-I causes. The MEN-I-specific deaths occurred at a younger age (median 47 years) than either MEN-I patients whose death was from some nonendocrine cause (median 60 years, p < 0.02) or than all kindred members who did not die of MEN-I disease (median 55 years, p < 0.05). The causes of death of the MEN-I patients included islet cell tumor (n = 12), ulcer disease (n = 6), hypercalcemia/uremia (n = 3), carcinoid tumor (n = 6), and nonendocrine malignancies (n = 9). There was no difference in survival between MEN-I carriers and unaffected kindred members. Of our MEN-I patients, 46% died from causes related to their endocrine tumors after a median age of 47 years, which was younger than family members who did not die from these tumors. Pancreatic islet cell tumors were the most common cause of death of MEN-I patients. Management of kindreds with MEN-I should include an aggressive screening program with early therapeutic intervention when a tumor is identified.