Incisional hernia recurrence through genomic profiling: a pilot study.

PURPOSE: Although situational risk factors for incisional hernia formation are known, the methods used to determine who would be most susceptible to develop one are unreliable. We hypothesized that patients with recurrent incisional hernias may possess unique gene expression profiles. METHODS: Skin and intact fascia were collected from 15 normal control (NC) patients with no hernia history and 18 patients presenting for recurrent incisional hernia (RH) repair. Microarray analysis was performed using whole genome microarray chips on NC (n = 8) and RH (n = 9). These samples were further investigated using a pathway-specific PCR array containing fibrosis-related genes. RESULTS: Microarray data revealed distinct differences in the gene expression profiles between RH and NC patients. One hundred and sixty-seven genes in the skin and 7 genes in the fascia were differentially expressed, including 8 directly involved in collagen synthesis. In particular, GREMLIN1, or bone morphogenetic protein antagonist 1, was under expressed in skin (fold = 0.49, p < 10(-7), q = 0.0009) and fascia (fold = 0.23, p < 10(-4), q = 0.095) of RH patients compared with NC. The PCR array data supported previous reports of decreased collagen I/III ratios in skin of RH versus NC (mean = 1.51 ± 0.73 vs. mean = 2.26 ± 0.99; one-sided t test, p = 0.058). CONCLUSION: To our knowledge, this is the first microarray-based analysis to show distinct gene expression profiles between the skin and fascia of RH and NC patients and the first report of an association between GREMLIN1 and incisional hernia formation. Our results suggest that gene expression profiles may act as surrogate markers that stratify patients into different groups at risk for hernia development prior to their initial surgery.

Method of preparing a decellularized porcine tendon using tributyl phosphate.

Extracellular matrix (ECM) materials are currently utilized for soft tissue repair applications such as vascular grafts, tendon reconstruction, and hernia repair. These materials are derived from tissues such as human dermis and porcine small intestine submucosa, which must be rendered acellular to prevent disease transmission and decrease the risk of an immune response. The ideal decellularization technique removes cells and cellular remnants, but leaves the original collagen architecture intact. The tissue utilized in this study was the central tendon of the porcine diaphragm, which had not been previously investigated for soft tissue repair. Several treatments were investigated during this study including peracetic acid, TritonX-100, sodium dodecyl sulfate, and tri(n-butyl) phosphate (TnBP). Of the decellularization treatments investigated, only 1% TnBP was effective in removing cell nuclei while leaving the structure and composition of the tissue intact. Overall, the resulting acellular tissue scaffold retained the ECM composition, strength, resistance to enzymatic degradation, and biocompatibility of the original tissue, making 1% TnBP an acceptable decellularization treatment for porcine diaphragm tendon.

Evaluation of a novel endoluminal stapling procedure to restrict the lower esophageal sphincter and reduce reflux.

BACKGROUND AND STUDY AIMS: An effective, safe, and long-lasting endoluminal treatment for gastroesophageal reflux disease (GERD) would be an attractive prospect. We developed an endoluminal technique to restrict and tighten the lower esophageal sphincter (LES), by using a transoral endoscopic stapling device in a porcine model. PATIENTS AND METHODS: Pre-interventional evaluation comprised endoscopy, manometry, and 48-hour pH measurement of the distal esophagus using the catheterless BRAVO pH capsule. By placing the endoluminal stapling device at the LES and firing a 2.5-cm staple line, a vertical plication was created. In five pilot pigs (phase 1), plications were placed in various locations at the LES. In another five pigs (phase 2), plications were placed uniformly at the mid level of the LES on the lesser curvature side. Measurements were repeated 2 weeks after the procedure. Necropsy and histological analysis were performed. RESULTS: Endoluminal stapling was successfully completed in all animals. In phase 2, the median procedure time was 15 minutes (range 10-55 minutes). LES pressure increased from 10.5 mmHg (+/- 2.5 mmHg) to 14.3 mmHg (+/- 3.8 mmHg) (P = 0.038). Median percentage of time with pH below 4 decreased from 6.6% (range 2.9%-48.8%) to 2.2% (range 0%-10.4%) (P = 0.043). Histology showed the staple line involving the muscular layer in all pigs. A gap was present in the central part of the staple line in three pigs resulting in a mucosa-muscular bridge of tissue. This bridge did not influence the results. CONCLUSION: This novel endoluminal technique is feasible and safe in a porcine model over 2 weeks. It is appealing due to its simplicity and ease of application. Further studies aimed at eliminating the gap in the staple line and investigating more animals over longer survival periods are needed.

Endoscopic colotomy closure after full thickness excision: comparison of T fastener with multiclip applier.

BACKGROUND AND STUDY AIMS: Safe, reliable, and efficient endoscopic closure of a colotomy is paramount for endoscopic full thickness excision of the colon. Two newly developed devices, the Tissue Apposition System (TAS) and the InScope Multi-Clip Applier (IMCA), may help to achieve this. The aim of this study was to determine the feasibility of using each device to close colotomies after full thickness wall excisions. MATERIAL AND METHODS: 12 pigs were used in the study. After laparoscopic full thickness excision of the colonic wall, the defect was closed using either the TAS or the IMCA. Closure was performed under laparoscopic vision. Success of colotomy closure, time taken for colotomy closure, postoperative infections, and complication rates were recorded. RESULTS: Complete closure was achieved in 6/6 pigs in the TAS group. In 5/6 pigs in the IMCA group closure was successful; in one pig laparoscopic assistance was used. Median closure time (range) was significantly lower in the TAS group at 48 minutes (15 - 51) vs. 76 minutes (43 - 145) in the IMCA group. There were no postoperative infections or complications. CONCLUSIONS: Endoscopic closure after full thickness colonic wall excision is feasible with both the TAS and the IMCA. Closure times are significantly shorter and handling is easier with the TAS. Combined use of both systems might be beneficial.

Characterization of heavyweight and lightweight polypropylene prosthetic mesh explants from a single patient.

Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the body's effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.

Use of porcine dermal collagen as a prosthetic mesh in a contaminated field for ventral hernia repair: a case report.

Chronic infection of a prosthetic mesh implant is a severe complication of ventral hernia repair, and mesh explantation is usually required in these cases. Biologic mesh implants have a possible role in ventral hernia repair in this setting. Here we present a case of chronic mesh infection following ventral hernia repair and the use of a biologic mesh to repair the existing defect following explantation of the infected mesh. Analysis of the explant material demonstrated possible oxidative degradation of the original polypropylene. A review of the literature follows.

Ruptured intrahepatic aneurysm as the initial manifestation of polyarteritis nodosa.

polyarteritis nodosa (PAN) is characterized by panarteritis involving all layers of the vessel wall of medium and small arteries and adjacent veins leading to thrombosis and aneurysmal dilatation. We present the case of a 21-year-old Caucasian man with an acute abdomen with a massive gastrointestinal (GI) hemorrhage caused by a large intrahepatic aneurysmal rupture needing surgery. This was the initial manifestation of underlying PAN, which had not been diagnosed before the event. This patient's postoperative course was complicated by continued hemorrhage prompting further diagnostic abdominal arteriography, which revealed multiple art-eurysms along the superior mesenteric artery. The aneurysmal wall biopsy revealed lymphocytic infiltrates, scattered giant cells, and minimal necrosis. A diagnosis of PAN was entertained based on arteriographic findings, although no pathognomonic demonstration of multiple visceral aneu-rysms is a characteristic finding of PAN, The patient survived the catastrophic event, and treatment with corticosteroids was initiated, which led to an uncomplicated hospital stay. Furthermore, outpatient follow ups showed continued clinical improvement with corticosteroid therapy and a repeat angiogram performed elsewhere demonstrated resolution of most of the aneurysms. Our case represents an unusual initial clinical manifestation of PAN and is one of the few cases reported with a torrential (GI) hemorrhage resulting from a rupture of an intrahepatic aneurysm, which is associated with increased mortality. The clinical significance of abdominal pain is not always apparent. It may occur in the absence of any gross intra-abdominal lesions, or, as in our patient, may herald an acute abdominal catastrophe. The clinician should consider PAN in the differential diagnosis of a massive GI hemorrhage. It is also important to note that early diagnosis followed by aggressive treatment can be lifesaving.

Cytokeratin immunostaining in differentiating primary ovarian carcinoma from metastatic colonic adenocarcinoma.

The differentiation of ovarian metastases from colonic carcinoma and primary ovarian carcinoma can be difficult. To assess the utility of cytokeratin 7 and cytokeratin 20 immunostains in this setting, we studied routinely processed, formalin-fixed tissue from 165 ovarian tumors, including 45 serous carcinomas, 40 mucinous carcinomas, 64 endometrioid carcinomas, and 16 metastatic colonic adenocarcinomas with an avidin-biotin immunohistochemical technique. A cytokeratin 7+/cytokeratin 20- immunophenotype was seen in 86% of the endometrioid carcinomas, 27% of the mucinous carcinomas, 40% of the serous carcinomas, and none of the metastatic colorectal carcinomas. Conversely, a cytokeratin 7-/cytokeratin 20+ immunophenotype was seen in 94% of the metastatic colonic tumors, 5% of the mucinous carcinomas, and none of the endometrioid or serous tumors. We concluded that cytokeratin immunostains can be helpful in distinguishing metastatic colonic adenocarcinoma from primary ovarian carcinomas, particularly endometrioid carcinomas. Rare ovarian mucinous carcinomas may show the same immunophenotype as metastatic colonic carcinomas.

B72.3 immunoreactivity in benign abdominal lymph nodes associated with gastrointestinal disease.

PURPOSE: Immunolocalization of the tumor-associated glycoprotein 72 antigen with the monoclonal antibody B72.3 has been used as a "cancer marker" in radioimmunoscintigraphy and radioimmunoguided surgery (RIGS). Radioimmunoscintigraphy and RIGS have been used to detect occult metastatic deposits from colorectal adenocarcinoma. It has been suggested that RIGS is superior to histologic examination in detecting lymph node metastases from colorectal cancer. To determine the specificity of immunodetection of the tumor-associated glycoprotein-72 antigen as a marker for metastatic adenocarcinoma, we studied benign intra-abdominal lymph nodes with B72.3 and an immunohistochemical technique. METHODS: Formaldehyde-fixed, paraffin-embedded sections of 276 benign abdominal lymph nodes, resected with 35 cases of colonic adenocarcinoma and 33 cases of benign gastrointestinal disorders, were evaluated for B72.3 immunoreactivity using an avidin-biotin complex immunohistochemical technique. Lymph nodes from cases of colonic carcinoma were also studied with cytokeratin immunostaining to help eliminate occult micrometastases. RESULTS: B72.3 immunoreactivity was seen in the germinal centers of benign lymph nodes associated with 49 percent of the cases of colonic adenocarcinoma and 12 percent of the cases of benign gastrointestinal disease. CONCLUSIONS: B72.3 immunoreactivity can be seen in benign abdominal lymph nodes associated with gastrointestinal disease. We advise caution in the use of diagnostic techniques that equate B72.3 immunoreactivity with the presence of adenocarcinoma.

Lewis X antigen immunostaining in the diagnosis of transitional cell carcinoma.

Immunodetection of the Lewis X antigen has been suggested as a useful adjunct in the diagnosis of transitional cell carcinoma. To determine the specificity of Lewis X antigen immunostaining in this setting, we studied routinely processed, formalin-fixed tissue from 38 transitional cell carcinomas and 42 nonneoplastic urothelial lesions using the P12 monoclonal antibody to Lewis X antigen and an avidin-biotin immunohistochemical technique. Because Lewis X immunostaining of occasional umbrella cells has previously been noted in normal urothelium, staining of umbrella cells was not considered sufficient for a positive reaction in our study. Immunoreactivity for Lewis X antigen was seen in 34 of 38 (89%) cases of transitional cell carcinoma, in three of three cases of urothelial dysplasia, and in 20 of 39 (51%) of the reactive urothelial lesions. We conclude that immunostaining for the Lewis X antigen is not specific in the diagnosis of transitional cell carcinoma.

Neodymium:yttrium-aluminum-garnet laser fusion of endarterectomy flaps.

PURPOSE: This study evaluated the efficacy of neodymium:yttrium-aluminum-garnet laser welding of flaps in canine arteries and in securing the distal flap during human carotid endarterectomy. METHODS: Endarterectomy flaps were created in both common carotid and both common femoral arteries in 12 dogs. The flaps were repaired with either the neodymium:yttrium-aluminum-garnet laser or with 6-0 polypropylene sutures. The arteries were removed after duplex scanning at either 7 or 28 days. Eighteen high carotid endarterectomy flaps in 16 patients have been subsequently secured with the laser welding technique. RESULTS: Laser repairs (125 +/- 19 joule) of the canine arteries were completed more quickly than suture repairs (mean 25 seconds vs 135 seconds, respectively; p < 0.04). Duplex ultrasonography revealed no discernable differences between the two groups of arteries. Arteries studied at 7 days revealed three microscopic flaps (two suture, one laser), more subintimal fibroblastic proliferation in suture than laser-repaired carotid arteries (3: 1, p = 0.0530), and similar amounts of inflammation in suture- and laser-repaired arteries. Arteries studied at 28 days revealed one microscopic intimal flap (suture-repaired); equal fibroblastic and inflammatory responses in suture- and laser-repaired vessels; and no evidence of laser thermal injury. Eighteen carotid endarterectomy flaps have been successfully fused with no immediate or long-term complications in 16 patients (follow-up of 0 to 24 months). CONCLUSION: Laser fusion appears to be a safe and effective method for securing distal carotid endarterectomy flaps.

Immunostaining in the diagnosis of pulmonary neuroendocrine carcinomas. An immunohistochemical study with ultrastructural correlations.

To determine the specificity of immunostaining in the diagnosis of pulmonary neuroendocrine carcinomas, we studied 66 ultrastructurally characterized lung cancers with a panel of markers considered to be selective for neuroendocrine tumors (neuron-specific enolase, chromogranin A, Leu 7, synaptophysin) and B72.3, which is reported to be selective for non-small-cell carcinomas. Neuroendocrine tumors studied included 13 small-cell carcinomas, four low-grade neuroendocrine carcinomas, and two large-cell carcinomas with neuroendocrine differentiation. Non-neuroendocrine tumors included 26 adenocarcinomas, 10 squamous cell carcinomas, and 11 large-cell undifferentiated carcinomas. The following percentages of neuroendocrine carcinomas showing immunoreactivity for the various "neuroendocrine markers" were found: synaptophysin, 100%; neuron-specific enolase, 74%; chromogranin A, 37%; and Leu 7, 5%. However, carcinomas without morphologic features of neuroendocrine differentiation showed the following immunoreactivity: synaptophysin, 62%; neuron-specific enolase, 60%; chromogranin A, 17%; and Leu 7, 9%. B72.3 immunostaining was seen in 81% of the carcinomas without neuroendocrine features and in 31% of the small-cell carcinomas. We conclude that many of the commercially available antibodies used as neuroendocrine markers are nonspecific in the diagnosis of pulmonary neuroendocrine carcinomas.

Lung cancer in nonsmoking women. Histology and survival patterns.

BACKGROUND: Despite the widespread view that important clinical and etiologic differences exist between histologic categories of lung cancer, few studies have examined the accuracy of hospital-reported pathologic diagnoses of lung cancer. METHODS: A review of pathologic material and an assessment of survival patterns were conducted in conjunction with a recently completed case-control study of lung cancer among nonsmoking women in Missouri. Using established protocols, tissue slides from tumors of 482 patients were reviewed by 3 pathologists. RESULTS: Adenocarcinoma was the most common histologic type among former smokers and lifetime nonsmokers. The overall agreement rate between the original and review diagnoses was 65.6%. The positive predictive value ranged from 0.33 for bronchioalveolar carcinomas to 0.84 for adenocarcinomas. Agreement rates for small, medium, and large hospitals were 63.1, 66.6, and 66.2%, respectively. Survival rates were highest for bronchioalveolar carcinoma and lowest for small cell carcinoma. CONCLUSION: Given the importance of lung cancer to public health and the need to examine risk by histologic type, these data indicate that pathologic review of registry-reported lung cancer cases may be an important component of large scale studies of etiology.

Utility of cytokeratin immunostaining in separating pulmonary adenocarcinomas from colonic adenocarcinomas.

Adenocarcinomas of uncertain origin are a frequent problem for surgical pathologists. To determine the utility of immunostaining for cytokeratin 7 and cytokeratin 20 in the separation of pulmonary adenocarcinomas from colonic adenocarcinomas, we studied routinely processed, formalin-fixed tissue from 151 of these tumors using commercially available monoclonal antibodies and an avidin-biotin immunohistochemical technique. Used alone, neither cytokeratin 7 immunostaining or cytokeratin 20 immunostaining reliably separated these tumors. However, the immunophenotype of cytokeratin 7 positive/cytokeratin 20 negative was seen in 86% of the pulmonary adenocarcinomas, and in 0% of the colonic adenocarcinomas. Conversely, the cytokeratin 7-negative/cytokeratin 20-positive immunophenotype was seen in 77% of the colonic carcinomas, and in 0% of the pulmonary tumors. In conclusion, cytokeratin 7/cytokeratin 20 immunostaining patterns may be helpful in separating pulmonary adenocarcinomas from colonic adenocarcinomas.

Reactive hemophagocytic syndrome simulating acute hepatitis. A case due to hepatic peripheral T-cell lymphoma.

The reactive hemophagocytic syndrome may mimic acute hepatitis, as we report here. It should be considered when hepatitis is accompanied by high fever, progressive cytopenias, and weight loss, with or without adenopathy and striking lactate dehydrogenase elevation. Bone marrow, lymph node, or liver biopsy are necessary to confirm the diagnosis. Recognition is important, because the syndrome has multiple potential causes amenable to therapy. Preliminary reports suggest that high-dose corticosteroid therapy is useful in suppressing cytokine-stimulated fever and hemophagocytosis, whatever the underlying cause.

Immunostaining for Leu-7 in the diagnosis of thyroid carcinoma.

The morphologic distinction between benign and malignant thyroid lesions can be difficult. Immunostaining for the Leu-7 antigen has been reported to be useful in the diagnosis of thyroid carcinoma. To test the specificity of immunostaining for Leu-7 in the diagnosis of thyroid carcinoma, we studied formalin-fixed, paraffin-embedded tissue specimens obtained from 66 thyroid lesions using the HNK-1 monoclonal antibody to Leu-7 and an avidin-biotin-complex technique. Positive reactivity for Leu-7 was seen in 11 (33%) of 33 benign thyroid conditions and in 27 (82%) of 33 thyroid carcinomas. We conclude that immunostaining for Leu-7 is not specific in the diagnosis of thyroid carcinoma.

Utility of BER-EP4 in the diagnosis of adenocarcinoma in effusions: an immunocytochemical study of 232 cases.

The usefulness of a new commercially available monoclonal antibody (MoAb) BER-EP4 was evaluated. This MoAb is directed against a cell surface glycoprotein reported to be present in most epithelial cells and epithelial tumors but not in mesothelial cells. Cell block sections from 103 adenocarcinomatous and 129 benign effusions were studied. Positive staining was seen in 85 of the 103 (83%) malignant effusions. Immunoreactivity was seen in 73-93% of adenocarcinomas from the ovary, gastrointestinal tract, lung, and breast. Mesothelial cells from 3 of the 129 (2%) benign effusions showed positive staining. It is concluded that immunocytochemical staining with MoAb BER-EP4 is a sensitive and specific aid in distinguishing reactive mesothelial cells from adenocarcinoma cells in body fluids.

Reactivity of B72.3 with adenocarcinomas. An immunohistochemical study of 476 cases.

BACKGROUND: The monoclonal antibody B72.3 has been shown to react with several common types of adenocarcinoma. However, the distribution of B72.3 reactivity in adenocarcinomas has not been well-enough defined to determine whether B72.3 immunostaining would be helpful in the diagnosis of adenocarcinoma of unknown origin. METHODS: Formaldehyde fixed, paraffin-embedded tissue from 476 adenocarcinomas from a variety of primary sites were studied using B72.3 and an avidin-biotin complex immunohistochemical technique. RESULTS: B72.3 immunoreactivity was seen in 75-100% of the adenocarcinomas from the ovary, endocervix, endometrium, distal esophagus/stomach, colon, lung, breast, prostate, pancreas, and bile ducts. Positive reactions were unusual in thyroid carcinomas (7%) and renal cell carcinomas (11%). B72.3 reactivity was not seen in the 20 hepatocellular carcinomas or 4 adrenal cortical carcinomas studied. CONCLUSIONS: B72.3 reacts with a wide variety of adenocarcinomas. Immunostaining with B72.3 may be helpful in excluding hepatocellular carcinoma in certain clinical settings.