Pathophysiology of acute pancreatitis

Local parenchymal damage in acute pancreatitis has been well recognized for many years. This damage leads to a considerable leak of extracellular fluid and so to gross hypovolemia. It also produces the pain that is a major clinical feature of the disease. More recently, the autodigestive process has been recognized to generate, within and around the gland, a broth of many components that is vasoactive and tissue destructive and which, in turn, produces systemic changes. These changes affect the whole body and may lead to multiorgan damage. The coagulation mechanism, heart action, peripheral resistance, liver function, as well as the lungs, kidneys, brain, and endocrine homeostatic mechanism are all affected; these patterns and their clinical implications are reviewed. When this multisystem failure occurs in its severest form, the patient may best be described as in a state of enzymic shock. This hypothesis is not just of academic interest; it provides a working concept upon which to base a more scientific treatment of acute pancreatitis.

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Résumé On connait bien, et depuis de nombreuses années, les lésions parenchymateuses locales de la pancréatite aigüe. Elles entraînent une perte considérable de liquide extracellulaire et donc une hypovolémie importante. Elles produisent également la douleur qui est un des symptomes capitaux de la maladie. On a découvert, plus récemment, que le processus d'autodigestion libère, dans la glande et autour d'elle, un bouillon contenant divers produits vaso-actifs et destructeurs de tissus. Ces produits peuvent, a leur tour, entraîner des perturbations de tout l'organisme et conduire à des défaillances multisystémiques. Les mécanismes de la coagulation, le travail cardiaque, la résistance périphérique, les fonctions hépatique, pulmonaire, rénale et cérébrale, l'homéostase endocrinienne sont tous perturbés: ces atteintes et leurs implications cliniques sont revues. Lorsque les défaillances multisystémiques atteignent leur forme la plus grave, on peut dire que le malade est en état de choc enzymatique. Ce concept n'est pas d'un intérêt purement académique. Il nous fournit une hypothèse de travail qui doit conduire à un traitement plus scientifique de la pancréatite aigüe.

     

Pathophysiology of pain in chronic pancreatitis: clinical implications from a surgical perspective

Pain is the main symptom and the major indication for surgery in a large proportion of patients with chronic pancreatitis. Since the characters of pain (including frequency, severity, duration and cause) differ among the patients with chronic pancreatitis, their management remains a difficult and challenging problem. Initial treatment is always conservative and may require a multidisciplinary approach involving gastroenterologist, anesthesiologist, psychologist for chemical addiction (alcohol and/or narcotics), and surgeon. When non-operative management fails to achieve pain relief and pain markedly alters quality of life, surgery should be considered. A thorough knowledge of the pathophysiology of pain offers the theoretical basis for both conservative and surgical treatment of chronic pancreatitis. The selection of the surgical procedure should be based on the structural changes of the pancreas.     

Pathophysiology and treatment of severe pancreatitis

The current study was designed to characterize toxic substances in hemorrhagic ascitic fluid by using in vivo dogs model and to examine the toxicity of hemorrhagic ascitic fluid by using an in vivo mice model injecting the fluid intraperitoneally. Our experiment showed that high levels of bradykinin, histamine and prostaglandin E were found in serum and in hemorrhagic ascitic fluid which reported as toxic substances during severe pancreatitis. A similar finding was also obtained clinically in four patients with severe acute pancreatitis. The mortality rate on 72 hours following the intraperitoneal injection of 2.0 and 3.0 ml of ascitic fluid were 66.0% and 89.7% respectively. Mice which died following the injection of ascitic fluid showed shock lung at autopsy. These results indicate that peritoneal lavage might be an effective method for the treatment of severe pancreatitis. We evaluated 25 patients with severe acute pancreatitis clinically. Laparotomy and drainage operations were performed in 16 patients of these patients. Twelve among 16 patient had good results. The cause of death were multiorgan failures.     

Complications of chronic pancreatitis

The most common complication of chronic pancreatitis is pain, which in many cases seems related to pancreatic ductal obstruction with ductal hypertension. Longitudinal pancreaticojejunostomy is indicated in patients with a dilated (larger than 7 mm) duct and pain that requires narcotic analgesics for relief. Chronic pseudocysts may be corrected surgically without the usual 6-week wait, and asymptomatic pseudocysts less than 4 cm in diameter may not require surgery at all. The relative efficacy and risks of percutaneous drainage of pseudocysts versus the standard surgical approaches need to be studied. Pancreatic fistulas may be external or internal, where pancreatic ascites or hydrothorax can be the clinical manifestation. The pharmacologic suppression of pancreatic secretion (e.g., with somatostatin) may be useful in their management, but surgery may be required. Pancreatic resection or internal drainage is usually effective. Persistent jaundice should be relieved surgically by choledochoduodenostomy to avoid the development of secondary biliary cirrhosis. Obstruction at various levels of the gastrointestinal tract (duodenum, small bowel, colon) may require bypass (gastrojejunostomy) or resection. Hemorrhage from major arteries is an infrequent but often lethal complication of chronic pancreatitis, especially associated with pseudocysts. Angiography is invaluable for diagnosis and occasionally for treatment (embolization). Surgery is preferred in good-risk patients, with suture ligation (resection) of the bleeding source. Chronic pancreatitis is the most common cause of splenic vein thrombosis. The resultant hemorrhage from gastric varices is managed effectively by splenectomy.     

慢性胰腺炎的分期探讨

目的 建立一种慢性胰腺炎分期系统并据此分析临床病例.方法 分析国内外慢性胰腺炎分期方式,提出临床实用的分期系统,据此对连续89例病人病情进行归纳分析.结果 该系统对形态学改变、疼痛、并发症及功能异常进行组合,构成四个阶段:Ⅰ、Ⅱ、Ⅲ和Ⅳ期各占1.1%、39.3%、44.9%和14.6%,疼痛发生率87.6%,并发症发生率46.1%.结论 该系统评价指标客观、实用,并可据分期选择治疗方式.