Sigmoid Colon Intraluminal Obstruction by a Detached Recurrent Ascending Colon Liposarcoma.

Primary liposarcoma of the colon is extremely rare in the literature. We present a case of a 51-year-old male patient with recurrent ascending colon liposarcoma, which caused obstructive ileus, just a few days prior to his scheduled elective operation and led us to expedite his surgery. The procedure was scheduled to be a robotic right colectomy. After finishing the operation and extracting the specimen, the tumour could not be detected; hence, an exploratory laparotomy was performed. Findings were a large tumour in the sigmoid colon, causing complete obstruction. Sigmoidectomy was performed, in order to remove the tumour. To our knowledge, this is the first case published in the literature, reporting a colonic tumour detachment, displacement and causing distal bowel occlusion. This event highlights the importance of careful intraoperative inspection in patients with known intraluminal bowel malignancies that present with signs and symptoms of obstruction and emphasises the need for further research on the risk factors for tumour detachment and subsequent bowel occlusion.

Chronic constipation in Parkinson's disease: clinical features and molecular insights on the intestinal epithelial barrier.

Background: Chronic constipation (CC) is a severe symptom in Parkinson's disease (PD), with an unclear pathogenesis. Abnormalities of the enteric nervous system (ENS) and/or intestinal epithelial barrier (IEB) may be pathophysiologically relevant in PD patients with CC. We investigated possible molecular changes of the IEB in PD/CCs compared with CCs and controls. Methods: Twelve PD/CCs (2 female, age range 51-80 years), 20 CCs (15 female, age range 27-78 years), and 23 controls (11 female, age range 32-74 years) were enrolled. Ten PD/CCs and 10 CCs were functionally characterized by anorectal manometry (AM) and transit time (TT). Colon biopsies were obtained and assessed for gene and protein expression, and localization of IEB tight junction markers claudin-4 (CLDN4), occludin-1 (OCCL-1), and zonula occludens-1 (ZO-1) by RT-qPCR, immunoblot and immunofluorescence labeling. Results: PD/CCs were clustered in 2 functional categories: patients with delayed TT and altered AM (60%), and a second group showing only modifications in AM pattern (40%). Gene expression of CLDN4, OCCL-1 and ZO-1 was higher in PD/CCs than controls (P<0.05). Conversely, PD/CCs showed a trend to decrease (P>0.05) in CLDN4 and OCCL-1 protein levels than controls, whereas ZO-1 protein was comparable. In PD/CCs compared with controls, decreasing tendency of vasoactive intestinal polypeptide mRNA, protein and immunoreactive fiber density were observed, although the difference was not statistically significant. Conclusion: Transit and anorectal dysfunctions in PD/CCs are associated with difference in ZO-1, OCCL-1 and CLDN4 expression, thus supporting the role of an altered IEB as a contributory mechanism to possible neuronal abnormalities.

An Automated Prognostic Model for Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) constitutes a leading cause of cancer-related mortality despite advances in detection and treatment methods. While computed tomography (CT) serves as the current gold standard for initial evaluation of PDAC, its prognostic value remains limited, as it relies on diagnostic stage parameters encompassing tumor size, lymph node involvement, and metastasis. Radiomics have recently shown promise in predicting postoperative survival of PDAC patients; however, they rely on manual pancreas and tumor delineation by clinicians. In this study, we collected a dataset of pre-operative CT scans from a cohort of 40 PDAC patients to evaluate a fully automated pipeline for survival prediction. Employing nnU-Net trained on an external dataset, we generated automated pancreas and tumor segmentations. Subsequently, we extracted 854 radiomic features from each segmentation, which we narrowed down to 29 via feature selection. We then combined these features with the Tumor, Node, Metastasis (TNM) system staging parameters, as well as the patient's age. We trained a random survival forest model to perform an overall survival prediction over time, as well as a random forest classifier for the binary classification of two-year survival, using repeated cross-validation for evaluation. Our results exhibited promise, with a mean C-index of 0.731 for survival modeling and a mean accuracy of 0.76 in two-year survival prediction, providing evidence of the feasibility and potential efficacy of a fully automated pipeline for PDAC prognostication. By eliminating the labor-intensive manual segmentation process, our streamlined pipeline demonstrates an efficient and accurate prognostication process, laying the foundation for future research endeavors.

Tumor Diagnosis against Other Brain Diseases Using T2 MRI Brain Images and CNN Binary Classifier and DWT.

PURPOSE: Brain tumors are diagnosed and classified manually and noninvasively by radiologists using Magnetic Resonance Imaging (MRI) data. The risk of misdiagnosis may exist due to human factors such as lack of time, fatigue, and relatively low experience. Deep learning methods have become increasingly important in MRI classification. To improve diagnostic accuracy, researchers emphasize the need to develop Computer-Aided Diagnosis (CAD) computational diagnostics based on artificial intelligence (AI) systems by using deep learning methods such as convolutional neural networks (CNN) and improving the performance of CNN by combining it with other data analysis tools such as wavelet transform. In this study, a novel diagnostic framework based on CNN and DWT data analysis is developed for the diagnosis of glioma tumors in the brain, among other tumors and other diseases, with T2-SWI MRI scans. It is a binary CNN classifier that treats the disease "glioma tumor" as positive and the other pathologies as negative, resulting in a very unbalanced binary problem. The study includes a comparative analysis of a CNN trained with wavelet transform data of MRIs instead of their pixel intensity values in order to demonstrate the increased performance of the CNN and DWT analysis in diagnosing brain gliomas. The results of the proposed CNN architecture are also compared with a deep CNN pre-trained on VGG16 transfer learning network and with the SVM machine learning method using DWT knowledge. METHODS: To improve the accuracy of the CNN classifier, the proposed CNN model uses as knowledge the spatial and temporal features extracted by converting the original MRI images to the frequency domain by performing Discrete Wavelet Transformation (DWT), instead of the traditionally used original scans in the form of pixel intensities. Moreover, no pre-processing was applied to the original images. The images used are MRIs of type T2-SWI sequences parallel to the axial plane. Firstly, a compression step is applied for each MRI scan applying DWT up to three levels of decomposition. These data are used to train a 2D CNN in order to classify the scans as showing glioma or not. The proposed CNN model is trained on MRI slices originated from 382 various male and female adult patients, showing healthy and pathological images from a selection of diseases (showing glioma, meningioma, pituitary, necrosis, edema, non-enchasing tumor, hemorrhagic foci, edema, ischemic changes, cystic areas, etc.). The images are provided by the database of the Medical Image Computing and Computer-Assisted Intervention (MICCAI) and the Ischemic Stroke Lesion Segmentation (ISLES) challenges on Brain Tumor Segmentation (BraTS) challenges 2016 and 2017, as well as by the numerous records kept in the public general hospital of Chania, Crete, "Saint George". RESULTS: The proposed frameworks are experimentally evaluated by examining MRI slices originating from 190 different patients (not included in the training set), of which 56% are showing gliomas by the longest two axes less than 2 cm and 44% are showing other pathological effects or healthy cases. Results show convincing performance when using as information the spatial and temporal features extracted by the original scans. With the proposed CNN model and with data in DWT format, we achieved the following statistic percentages: accuracy 0.97, sensitivity (recall) 1, specificity 0.93, precision 0.95, FNR 0, and FPR 0.07. These numbers are higher for this data format (respectively: accuracy by 6% higher, recall by 11%, specificity by 7%, precision by 5%, FNR by 0.1%, and FPR is the same) than it would be, had we used as input data the intensity values of the MRIs (instead of the DWT analysis of the MRIs). Additionally, our study showed that when our CNN takes into account the TL of the existing network VGG, the performance values are lower, as follows: accuracy 0.87, sensitivity (recall) 0.91, specificity 0.84, precision 0.86, FNR of 0.08, and FPR 0.14. CONCLUSIONS: The experimental results show the outperformance of the CNN, which is not based on transfer learning, but is using as information the MRI brain scans decomposed into DWT information instead of the pixel intensity of the original scans. The results are promising for the proposed CNN based on DWT knowledge to serve for binary diagnosis of glioma tumors among other tumors and diseases. Moreover, the SVM learning model using DWT data analysis performs with higher accuracy and sensitivity than using pixel values.

Bilateral palsy of the hypoglossal nerve following general anesthesia for emergency surgery. A case report.

INTRODUCTION AND IMPORTANCE: Hypoglossal nerve palsy is a rare condition usually associated with tumors, trauma, stroke or multiple sclerosis. It can be associated with other cranial nerve palsies while injury to this nerve typically affects a patient's articulation by causing lingual motility disturbance and swallowing difficulty. Bilateral isolated hypoglossal nerve palsy is an even more infrequent condition, which can occasionally be due to airway manipulation. CASE PRESENTATION: We describe a case of bilateral hypoglossal nerve damage following general anesthesia for emergency surgery, presenting with dysarthria, immobility of the tongue and dysphagia after extubation. The patient had a gradual recovery of all lost functions during the next four months. CLINICAL DISCUSSION: Bilateral hypoglossal nerve palsy is a very rare entity and tracheal tube malposition or prolonged but unnoticed tracheal cuff pressure especially in the face of low blood pressure, should be considered as possible causative mechanisms for this condition. This underlines the importance of careful positioning of the patient's head and neck during surgery as well as the meticulous and correct performance of routine maneuvers of airway management. CONCLUSION: Bilateral hypoglossal nerve palsy is a very rare entity. Diagnosis and management of twelfth nerve palsy require a multidisciplinary approach to achieve the best patient outcome.

The contribution of oncovascular surgery in a young patient with idiopathic retroperitoneal fibrosis.

Surgical resection remains the cornerstone for the treatment of oncological disease. When a critical arterial or venous structure is involved in a tumor mass, successful relief of symptoms and long-term oncological control are achieved through careful preoperative planning by an interdisciplinary team that necessarily includes a vascular surgeon. We describe the involvement of a vascular surgeon in the oncology of a 22-year-old woman, who is diagnosed with idiopathic retroperitoneal fibrosis.

Severity of Pancreatic Leak in Relation to Gut Restoration After Pancreaticoduodenectomy: The Role of the Roux-en-Y Configuration.

Background: Pancreatic leak after pancreaticoduodenectomy and gut restoration via a single jejunal loop remains the crucial predictor of patients' outcome. Our reasoning that active pancreatic enzymes may be more disruptive to the pancreatojejunostomy prompted us to explore a Roux-en-Y configuration for the gut restoration, anticipating diversion of bile salts away from the pancreatic stump. Our study aims at comparing two techniques regarding the severity of postoperative pancreatic fistula (POPF) and patients' outcome. Methods: The files of 415 pancreaticoduodenectomy patients were retrospectively reviewed. Based on gut restoration, the patients were divided into: cohort A (n = 105), with gut restoration via a single jejunal loop, cohort B (n = 140) via a Roux-en-Y technique assigning the draining of pancreatic stump to the short limb and gastrojejunostomy and bile (hepaticojejunostomy) flow to long limb, and cohort C (n = 170) granting the short limb to the gastric and pancreatic anastomosis, whereas hepaticojejunostomy was performed to the long limp. The POPF-related morbidity and mortality were analyzed. Results: Overall POPF in cohort A versus cohorts B and C was 19% versus 12.1% and 9.4%, respectively (P = 0.01 A vs B + C). POPF-related morbidity in cohort A versus cohorts B and C was 10.5% versus 7.3% and 6.3%, respectively (P = 0.03 A vs B+C). POPF-related total hospital mortality in cohorts A versus B and C was 1.9% versus 0.8% and 0.59%, respectively (P = 0.02 A vs B+C). Conclusion: Roux-en-Y configuration showed lower incidence and severity of POPF. Irrespective of technical skill, creating a gastrojejunostomy close to pancreatojejunostomy renders the pancreatic enzymes less active by leaping the bile salts away from the pancreatic duct and providing a lower pH.

Two Needle Passes Achieve Similar Diagnostic Yield Compared to Three Passes Regarding Diagnosis of Solid Pancreatic Lesions in Endoscopic Ultrasound-Guided Fine Needle Aspiration.

Current guidelines advocate 3-4 passes with a fine-needle aspiration (FNA) to achieve high rates of diagnostic samples for malignancy when performing endoscopic ultrasound (EUS)-guided sampling of solid pancreatic lesions, in the absence of on-site cytologic evaluation. The aim of this study is to compare 2 vs. 3 needle passes in EUS-FNA for solid pancreatic lesions in terms of incremental diagnostic yield and to identify factors associated with the procedure's outcome. In this retrospective study, 2 passes of EUS-FNA were found to have similar diagnostic yield compared to 3 passes for the diagnosis of solid pancreatic masses, suggesting that there might be no significant incremental tissue yield when 3 passes are performed.

Solid Pseudopapillary Tumor of the Pancreas in a 25-Year-Old Female: A Rare Entity of Pancreatic Tumors.

Solid pseudopapillary neoplasms (SPMs) of the pancreas are extremely rare tumors of the pancreas that typically affect young women and have a favorable prognosis. Herein, we report a 25-year-old female with solid pseudopapillary tumor of the pancreas who presented with atypical epigastric pain. The patient underwent pancreatoduodenectomy (Whipple procedure). She remained asymptomatic and showed no signs of disease after one year of follow-up. This type of pancreatic tumors is amenable to cure after complete surgical resection, even in cases with capsular invasion, unlike any other malignant tumors of the pancreas.

Distal pancreatectomy after pancreatic injury, in two pediatric patients.

INTRODUCTION: Although serious trauma is rare in pediatric patients, the management of blunt force trauma to the abdomen remains a challenge for Child Surgery Departments. Pancreatic injury comprises the fourth most common injury among the solid organs and cases accompanied by rupture of the main pancreatic duct (MPD) present a further challenge for physicians (Fayza Haider et al.; Wood et al., 2010; Jobst et al., 1999; Grosfeld et al., 2006). CASE PRESENTATION: Two adolescents, both 13 years old, where referred to our Pediatric Hospital, due to blunt force abdominal trauma. During admission, both patients were hemodynamically stable, in good general condition but suffering from abdominal pain and vomiting. After a full diagnostic check-up, grade IV pancreatic injury was diagnosed in both patients and they were taken to the operation room 3 and 6 days post-injury. Intra-operatively a distal pancreatectomy along with splenectomy was performed in both cases, with catheterization and ligation of the main pancreatic duct. Both patients were admitted to the pediatric ICU for 2 and 4 days. Both made an uneventful recovery and remain well 6 months postoperatively. CONCLUSION: While hemodynamically stable, patients with Grade IV pancreatic injury, benefit from sub-acute management, allowing for planning of the surgical intervention. Distal pancreatectomy with splenectomy, along with catheterization and ligation of the main pancreatic duct, has excellent post-operative results. The chief of the Pediatric Hospital, said that in 35 years at pediatric surgery, is the first time with the need of operative management, in pancreatic injury. The hepatobiliary surgical expert in adults, who was consulted in both cases, said that without the surgeries, both children were going to die.

Does vascular occlusion in liver resections predispose to recurrence of malignancy in the liver remnant due to ischemia/reperfusion injury? A comparative retrospective cohort study.

BACKGROUND: Severe ischemic changes of the liver remnant after hepatectomy could expedite tumor recurrence on the residual liver. Our study aimed at assessing the effect of warm ischemic/reperfusion (I/R) injuries on surgery-to-local recurrence interval and patient overall survival, during major hepatectomies under inflow and outflow vascular control. METHODS: One hundred and eighteen patients were subjected to liver resection under total inflow and outflow vascular clamping and were assigned as study group. These individuals were retrospectively matched to 112 counterparts, who underwent liver surgery applying inflow and outflow vascular clamping only of the segment harboring the tumor, sparing the liver remnant from any I/R injury (control group). The two cohorts were compared regarding recurrence-free survival and overall survival. RESULTS: Reversible I/R injuries of the liver remnant subjected to vascular clamping were manifested, with increase of AST values at postoperative day 2 in the study group, as compared to the control group (603 ± 270 U/L vs. 450 ± 290 U/L, p < 0.001), reversing to normal by day 7. Recurrence-free survival and overall survival were no significantly different between the two groups (log rank statistic p = 0.298 and 0.639, respectively). CONCLUSION: Reversible I/R injuries of the liver remnant do not seem to be implicated in the precipitation of local malignant recurrence or in shorter long-term survival, in comparison to a technique sparing the residual liver of I/R injury. This retrospective cohort study was registered at clinicaltrials.gov under unique identifying number: NCT04257240.

Pancreatic intraductal papillary mucinous neoplasm masquerading as ampullary adenoma: a diagnostic puzzle.

Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cystic lesion, remaining mostly asymptomatic. An atypical presentation of such a lesion, initially thought to be an ampullary adenoma, is presented herein. A 78-year-old white male with painless jaundice was treated in a tertiary hospital. Imaging and endoscopic investigations pointed towards an ampullary adenoma obstructing and causing dilatation of both bile and pancreatic ducts. Endoscopic papillectomy was carried out and histology revealed tubulovillous adenoma. Follow-up duodenoscopy 3 months later showed a recurrent lesion with mucous leaking from the pancreatic duct. Cytology revealed mucin-rich atypical cells, consistent with main-duct IPMN. Pancreatoduodenectomy was performed, finally revealing main-duct IPMN protruding through Vater's ampulla. Cystic pancreatic lesions are increasingly found and IPMN is the most common of these. On the other hand, the management of ampullary adenomas has been revolutionized by endoscopic treatment and the advent of endoscopic papillectomy, with expanding indications. Meticulous clinical and imaging work up of these patients is essential to avoid suboptimal treatment. IPMN should be included in the differential diagnosis of ampullary adenomas, especially in the presence of a grossly dilated pancreatic duct.

A Duplicated Gallbladder in a Patient Presenting with Acute Cholangitis. A Case Study and a Literature Review.

Gallbladder duplication can present a clinical challenge primarily due to difficulties with diagnosis and identification. Recognition of this anomaly and its various types is important since it can complicate a gallbladder disease or a simple hepatobiliary surgical procedure. The case report of a 63-year-old woman who presented with cholangitis and underwent a successful laparoscopic management of symptomatic gallbladder duplication is described, emphasizing several important considerations. Using ERCP, MRCP and 3D reconstructions the two cystic ducts with one common bile duct were identified. A review of the literature in referral of this variant, its anatomical classifications and significance to clinical and surgical practice is included. In conclusion, gallbladder anomalies should be anticipated in the presence of a cystic lesion reported around the gallbladder when evaluating radiologic studies. In case of surgery, preoperative diagnosis is essential to prevent possible biliary injuries or reoperation if accessory gallbladder has been overlooked during initial surgery. Laparoscopic cholecystectomy remains feasible for intervention can be safely done and awareness is necessary to avoid complications or multiple procedures.

Immune-related intestinal pseudo-obstruction associated with nivolumab treatment in a lung cancer patient.

Immune checkpoint inhibition therapy using targeted monoclonal antibodies is a new therapeutic approach with significant survival benefit for patients with several cancer types. However, their use can be associated with unique immune-related adverse effects as a consequence of impaired self-tolerance due to loss of T-cell inhibition via a nonselective activation of the immune system. Nivolumab is an anti-PD-1 immune checkpoint inhibitor that was recently developed for cancer immunotherapy with remarkable responses in nonsmall cell lung cancer patients. We present a 62-year-old Caucasian male with recurrent lung adenocarcinoma and currently under third-line therapy with nivolumab, who was admitted in our hospital with abdominal distension. Radiologic findings were consistent with small bowel ileus. After four days of conservative treatment, the patient underwent exploratory laparotomy where no cause of ileus was discovered. Postoperative the ileus persisted and considering that an adverse effect of the immune checkpoint inhibition therapy occurred, the patient received high-dose prednisone resulting in gradual improvement of symptoms. Immune checkpoint inhibitors may induce adverse effects to unaffected organ systems and tissues including the skin, gastrointestinal, hepatic, pulmonary, and endocrine system. The mainstay treatment consists of immunosuppression with corticosteroids in the majority of cases. As the clinical use of immune checkpoint inhibitors is expanding rapidly, there is an emergence of unique immune-related adverse effects in a growing patient population. Gaining early awareness is essential in these patients in order to ensure prompt diagnosis and management.

Pelvic Exenteration Put into Therapeutical and Palliative Perspective: It Is Worth to Try.

Pelvic exenteration (PE) is one of the most drastic operations in surgical oncology, associated with severe morbidity and mortality. The objective of our study was to review our experience of PE in terms of surgical characteristics, complications, and overall survival. All patients who had PE surgery between January 1999 and December 2015 were identified. Patients with verified distant metastatic disease were excluded. Patients with advanced pelvic tumors experiencing incapacitating postradiation severe damages were included. The following parameters were recorded: age, sex, indication for surgery, tumor histology, type of exenteration, urinary tract and colon reconstruction methods, operative time, blood transfusion, intensive care unit admissions, length of hospital stay and readmissions, and characteristics of perioperative morbidity and mortality. A total of 25 patients were submitted to PE by our surgical team. Most of the patients suffered from cervical cancer followed by bowel cancer. There was no perioperative mortality. Early postoperative complications ensued in 56% of the patients. Most complications involved the urinary system. Five years survival was estimated at 38%. Most patients (n = 9, 36%) died due to their primary disease, 5 (20%) died because of complications following operation, and 2 (8%) died because they denied oral feeding, which was associated with depression. Patients with a variety of malignancies can benefit from PE. Meticulous surgical technique, perioperative care, counseling, and nutritional support play an important role.

Biliary Mucinous Cystic Neoplasm of the Liver with Ovarian Stroma and Elevated Serum and Cystic Fluid Cancer Antigen 19-9 Levels.

Biliary mucinous cystic neoplasms of the liver are rare cystic tumors comprising less than 5% of the liver cystic neoplasms. These tumors demonstrate a female predominance and entail a risk of malignant transformation. We present a 56-year-old female patient with a multiloculated liver cystic lesion measuring 22 cm who underwent a cystectomy with en bloc resection of the liver segments II, III, and cholecystectomy. Serum cancer antigen 19.9 was 4,122.00 U/ml, supporting the diagnosis of a biliary cystic tumor. The cytology of the cystic fluid was negative for malignancy and intracystic fluid cancer antigen 19.9 level was measured over 12,000.00 U/l. The patient is free of recurrence at one-year follow up. Although a rare entity, the biliary mucinous cystic neoplasms should be considered in the differential diagnosis in the patients with liver cystic tumors. The appropriate management with complete surgical resection with negative margins is recommended given the risk of recurrence and malignant transformation.

Granuloma Mimicking Local Recurrence on PET/CT after Liver Resection of Colorectal Liver Metastasis: A Case Report.

Positron emission tomography-computed tomography (PET/CT) improves the diagnostic interpretation of fluorine-18 fluorodeoxyglucose (18F-FDG ) PET and CT in oncologic patients and has an impact on both diagnostic and therapeutic aspects of patient management. However, false positive findings from the PET/CT imaging should be taken into consideration as they mislead physicians into improper therapeutic actions. We present a 48-year-old female patient with a history of left colectomy for colorectal cancer and subsequent liver metastasectomy. After one year of follow-up, she presented with a highly suspicious lesion in the liver, which was confirmed on PET/CT as a metastatic liver tumor. Consequently, the patient underwent surgical excision of the tumor, and the definitive histological diagnosis showed a granulomatous tissue with giant cells and foreign body tissue reaction. Based on this report, we briefly review the dangerous pitfalls from radiological and PET/CT imaging concerning the preoperative diagnostic workup examination, as they may significantly alter the treatment plan in oncologic patients.

Effects of Lornoxicam on Anastomotic Healing: A Randomized, Blinded, Placebo-Control Experimental Study.

Introduction and Aim. With the implementation of multimodal analgesia regimens, Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) are often administered for optimal pain control and reduction of opioid use. The aim of the study was to examine the effects of lornoxicam, a NSAID, on anastomotic healing employing an animal model. Materials and Methods. A total of 28 Wistar rats were randomly assigned in two groups. All animals underwent ascending colonic transection followed by an end-to-end hand sewn anastomosis. Group 1 received intraperitoneally lornoxicam before and daily after surgery. Group 2 received intraperitoneally an equal volume of placebo. Half of the animals in each group were euthanized on the 3rd pod and the remaining on the 7th pod. Macro- and microscopic indicators of anastomotic healing were compared using a two-tailed Fisher exact test. Results. The lornoxicam group significantly decreased fibroblast in growth and reepithelization of the mucosa at the anastomotic site on the 3rd pod and significantly increased occurrence of deep reaching defects, necrosis, and microabscess on the 7th pod. Conclusion. Lornoxicam administration during the perioperative period adversely affects histologic parameters of intestinal anastomotic healing. These effects of lornoxicam administration were not found to induce significant increase of anastomotic dehiscence in the rat model.