Faculty Bibliography

BACKGROUND:Delayed gastric emptying (DGE) occurs in 14% to 61% of patients after pylorus-preserving pancreaticoduodenectomy, but its pathogenesis is unclear. We hypothesized that DGE may be due to pylorospasm secondary to vagal injuries at operation and may be preventable by the addition of pyloromyotomy. METHODS:Patients operated on consecutively between April 2000 and August 2003 were studied. Pyloromyotomy was of the Fredet-Ramstedt type combined with antroplasty. DGE-free recovery was defined as tolerance of a diet for three successive days by postoperative day 8. The symptom of nausea was used as a basis for nasogastric tube removal and diet resumption. A gastric emptying test (GET) with solid food was obtained. Patients with difficulty swallowing were fed via a feeding tube. RESULTS:There were 47 patients. Two patients were excluded because of death (n = 1) and ileus with pancreatic fistula (n = 1). Diagnoses were pancreatic cancer (n = 23), chronic pancreatitis (n = 11), ampullary cancer (n = 5), mucinous cystic neoplasm (n = 5), and duodenal villous adenoma (n = 3). Median times to nasogastric tube removal, start of liquid diet, and start of solid diet were postoperative days 2, 3, and 5, respectively. Two patients had tube feedings. Preoperative GET was abnormal in 51%, and postoperative GET was abnormal in 37%. The average length of stay was 9.5 days (median, 7 days). DGE occurred in only one patient (2.2%). There were no late complications during a 6-month follow-up. CONCLUSIONS:The addition of pyloromyotomy to pylorus-preserving pancreaticoduodenectomy is effective in preventing DGE. Results are supportive of the hypothesis that DGE may be caused by operative injuries of the vagus innervating the pyloric region.

A number of genetic mutations have recently been identified that appear to be important in the development of pancreatitis. Point mutations in the cationic trypsinogen gene are capable of initiating pancreatitis. These mutations also provide important insights into the pathophysiology of acute pancreatitis and into potential connections between acute and chronic pancreatitis. Mutations in the genes encoding for the pancreatic secretory trypsin inhibitor and the cystic fibrosis transmembrane conductance regulator more likely work in concert with other genes and environmental factors in affecting disease susceptibility. Although the subject so far has received only a limited amount of study, genetic polymorphisms in a wide range of genes relating to pancreatic function and to regulation of inflammation are likely to play major roles in determining each individual's susceptibility to developing pancreatitis, and its severity if it does develop.

BACKGROUND:EUS-guided fine-needle aspiration is rapidly becoming the procedure of choice for the diagnostic evaluation of pancreatic masses. Acute pancreatitis has been reported after EUS-guided fine-needle aspiration of the pancreas. This study evaluated the effect of EUS-guided fine-needle aspiration on the pancreas by serial measurement of amylase and lipase levels and determining the frequency of acute pancreatitis after EUS-guided fine-needle aspiration of pancreatic masses. METHODS:In 100 consecutive patients referred for EUS-guided fine-needle aspiration of a pancreatic mass, amylase and lipase levels were determined immediately before and within 2 hours after the procedure. Additionally, patients were questioned as to the occurrence of symptoms of acute pancreatitis within 48 hours after EUS-guided fine-needle aspiration. RESULTS:For 2 of 100 patients (2%) there was clinical and biochemical evidence of acute pancreatitis after EUS-guided fine-needle aspiration. Both patients had a history of recent pancreatitis. In addition, there was a significant increase in postprocedure lipase levels (p = 0.40) compared with amylase levels in this patient subset. CONCLUSION/CONCLUSIONS:The frequency of acute pancreatitis after EUS-guided fine-needle aspiration of the pancreas was 2% in this study. A history of recent pancreatitis appears to be a potential risk factor. Amylase and lipase levels can be elevated after EUS-guided fine-needle aspiration and in most cases have no clinical significance.

Acute HIV-1 infection depletes CD4(+) T cells in gut-associated lymphoid tissue (GALT). The failure of containment of local viral replication, and consequent CD4(+) T cell depletion, might be due to delayed mobilization of effector CD8(+) T cells or absence of functioning HIV-1-specific CD8(+) T cell effectors within GALT. No studies have addressed human intestinal HIV-1-specific CD8(+) T cell functions. We sought to determine whether functional HIV-1-specific CTL were present in GALT and whether the repertoire differed from HIV-1-specific CTL isolated from peripheral blood mononuclear cells. From three HIV-1-infected subjects, we isolated HIV-1-specific CD8(+) T cells expressing the mucosal lymphocyte integrin CD103 from GALT. These antigen-specific effector cells could be expanded in vitro and lysed target cells in an MHC class I-restricted manner. HIV-1-specific CTL could be isolated from both duodenal and rectal GALT sites, indicating that CD8(+) effectors were widespread through GALT tissue. The breadth and antigenic specificities of GALT CTL appeared to differ from those in peripheral blood in some cases. In summary, we found HIV-1-specific CD8(+) effector T cells in GALT, despite HIV-1-induced CD4(+) T cell lymphopenia. This suggests that HIV-1-specific CTL in gut tissue can be maintained with limited CD4(+) T cell help