Matthias Stelzner

Percutaneous cholecystostomy for acute cholecystitis in veteran patients

BACKGROUND Surgical cholecystostomy has been shown to carry a significantly higher mortality rate at Veterans Administration (VA) hospitals than at non-federal hospitals in the past. METHODS A retrospective outcomes study was undertaken at a large VA medical center with a policy favoring radiologic over surgical cholecystostomy over the past 9 years. Records of 24 consecutive patients with acute cholecystitis were reviewed to evaluate the effectiveness of the procedure. RESULTS Cholecystostomy was performed radiologically in 22 patients and surgically in 2 patients. Most (78%) of patients improved within 48 hours. The periprocedural mortality was 25%. The majority of these patients died from unrelated illnesses. Four patients developed complications, none of which required operative intervention. CONCLUSIONS Comorbidities are the most important mortality factor for cholecystostomies in VA patients. Radiologic tube placement is effective and uncomplicated in most cases.

The utility of routine preoperative computed tomography scanning in the management of veterans with colon cancer

BACKGROUND The aim of this study is to assess the clinical utility of routine preoperative computed tomography (CT) scanning in patients with cancer of the intraperitoneal colon. METHODS From November 1997 to June 2001, all patients at VA Puget Sound Healthcare System with a diagnosis of colon cancer were referred for a preoperative CT scan. Medical records and operative notes were reviewed to determine the influence of preoperative CT on clinical management. RESULTS Seventy patients received a CT per protocol. Preoperative CT provided information that was used in treatment planning and management in 26 (37%) cases. However, if preoperative scans had not been performed, the clinical management would have been definitively altered in only 13 (19%) patients. CONCLUSIONS Although these data suggest potential benefit for routine preoperative CT scanning, we believe additional study, including cost analysis, should precede the adoption of CT scanning as a routine preoperative study in patients with colon cancer.

The prevalence and natural history of gallstones in spinal cord injured patients

BACKGROUND Individuals with a spinal cord injury are at increased risk for the development of gallstones. Because these patients cannot reliably manifest classic symptoms of biliary colic, they may be more likely to present with advanced biliary complications than patients with intact abdominal innervation. The natural history of gallstones in spinal cord injured patients has not been described. STUDY DESIGN All spinal cord injured patients seen at the Seattle Veterans Affairs Medical Center from January 1, 1993, to December 31, 1997 were included in the study. For each patient, the presence or absence of gallstones had been determined previously through screening abdominal ultrasonographic evaluations. Pertinent demographic information was obtained from medical records and patient interviews. Patients with gallstones were followed until death, cholecystectomy, or the conclusion of the study, and the annual incidence of biliary complications and patients requiring a cholecystectomy were determined. The prevalence of gallstones was established by studying the subset of patients seen at the Seattle Spinal Cord Injury Unit from January 1, 1995 to December 31, 1997. RESULTS Among the spinal cord injured patients, 31% either had gallstones or had undergone a cholecystectomy at some point after their injury. Increasing age, female gender, and greater severity of injury were risk factors for the formation of gallstones. Over the first 5 years after the diagnosis of gallstones, the annual incidence of cholecystectomy or biliary complications was 6.3% and 2.2%, respectively. CONCLUSIONS Spinal cord injured patients are at increased risk for the development of gallstones. Patients with gallstones are at an increased risk for the development of biliary complications compared with neurologically intact patients, but the magnitude of this risk does not warrant prophylactic cholecystectomy.

Comparison of Polyester Scaffolds for Bioengineered Intestinal Mucosa

Introduction: Biodegradable polyester scaffolds have proven useful for growing neointestinal tissue equivalents both in vitro and in vivo. These scaffolds allow cells to attach and grow in a 3-dimensional space while nutrient flow is maintained throughout the matrix. The purpose of this study was to evaluate different biopolymer constructs and to determine mucosal engraftment rates and mucosal morphology. Hypothesis: We hypothesized that different biopolymer constructs may vary in their ability to provide a good scaffolding onto which intestinal stem cell organoids may be engrafted. Study Design: Eight different microporous biodegradable polymer tubes composed of polyglycolic acid (PGA), polylactic acid, or a combination of both, using different fabrication techniques were seeded with intestinal stem cell clusters obtained from neonatal rats. Three different seeded polymer constructs were subsequently placed into the omentum of syngeneic adult recipient rats (n = 8). Neointestinal grafts were harvested 4 weeks after implantation. Polymers were microscopically evaluated for the presence of mucosal growth, morphology, scar formation and residual polymer. Results: Mucosal engraftment was observed in 7 out of 8 of the polymer constructs. A maximal surface area engraftment of 36% (range 5–36%) was seen on nonwoven, randomly entangled, small fiber PGA mesh coated with aerosolized 5% poly-L-lactic acid. Villous and crypt development, morphology and created surface area were best on PGA nonwoven mesh constructs treated with poly-L-lactic acid. Electrospun microfiber PGA had poor overall engraftment with little or no crypt or villous formation. Conclusion: Intestinal organoids can be engrafted onto biodegradable polyester scaffoldings with restitution of an intestinal mucosal layer. Variability in polymer composition, processing techniques and material properties (fiber size, luminal dimensions and pore size) affect engraftment success. Future material refinements should lead to improvements in the development of a tissue-engineered intestine.

A simple method for measuring of intestinal solute transport in mucosal biopsy specimens

Accurate in vitro measurements of intestinal mucosal solute uptake in humans are often difficult because only small amounts of tissue material are available. We describe a miniaturized everted sleeve method of measuring intestinal solute uptake in endoscopy biopsy samples that combines simplicity, good tissue viability and reproducibility. Biopsies were mounted on a dressmaker needle head stationed immediately over a stirring bar rotating at 1200 rpm. This approach was used to measure taurocholate uptake in sheep and human endoscopy biopsies. Comparison was made to conventional standardized everted sleeve preparations. Na+-dependent uptake rates correlated well among individual sheep (R2 = 0.88, P < 0.05). There was excellent correlation between conventional and biopsy preparations in humans (R2 = 0.98; P < 0.05). The biopsy method overestimated diffusional uptake rates in sheep and humans by two to three fold when compared to conventional everted sleeve preparations. We conclude that this method is valuable to measure Na+-dependent solute uptake rates in biopsy samples from human intestine.

Ileal mucosal bile acid absorption is increased in Cftr knockout mice

BackgroundExcessive loss of bile acids in stool has been reported in patients with cystic fibrosis. Some data suggest that a defect in mucosal bile acid transport may be the mechanism of bile acid malabsorption in these individuals. However, the molecular basis of this defect is unknown. This study examines the expression of the ileal bile acid transporter protein (IBAT) and rates of diffusional (sodium independent) and active (sodium dependent) uptake of the radiolabeled bile acid taurocholate in mice with targeted disruption of the cftr gene.MethodsWild-type, heterozygous cftr (+/-) and homozygous cftr (-/-) mice were studied. Five one-cm segments of terminal ileum were excised, everted and mounted onto thin stainless steel rods and incubated in buffer containing tracer 3H-taurocholate. Simultaneously, adjacent segments of terminal ileum were taken and processed for immunohistochemistry and Western blots using an antibody against the IBAT protein.ResultsIn all ileal segments, taurocholate uptake rates were fourfold higher in cftr (-/-) and two-fold higher in cftr (+/-) mice compared to wild-type mice. Passive uptake was not significantly higher in cftr (-/-) mice than in controls. IBAT protein was comparably increased. Immuno-staining revealed that the greatest increases occurred in the crypts of cftr (-/-) animals.ConclusionsIn the ileum, IBAT protein densities and taurocholate uptake rates are elevated in cftr (-/-) mice > cftr (+/-) > wild-type mice. These findings indicate that bile acid malabsorption in cystic fibrosis is not caused by a decrease in IBAT activity at the brush border. Alternative mechanisms are proposed, such as impaired bile acid uptake caused by the thick mucus barrier in the distal small bowel, coupled with a direct negative regulatory role for cftr in IBAT function.