Spezielle Gesichtspunkte postoperativer Komplikationen in der Viszeralchirurgie

Increased mortality and altered local immune response in secondary peritonitis after previous visceral operations in mice

Postoperative peritonitis is characterized by a more severe clinical course than other forms of secondary peritonitis. The pathophysiological mechanisms behind this phenomenon are incompletely understood. This study used an innovative model to investigate these mechanisms, combining the models of murine Colon Ascendens Stent Peritonitis (CASP) and Surgically induced Immune Dysfunction (SID). Moreover, the influence of the previously described anti-inflammatory reflex transmitted by the vagal nerve was characterized. SID alone, or 3 days before CASP were performed in female C57BL/6 N mice. Subdiaphragmatic vagotomy was performed six days before SID with following CASP. The immune status was assessed by FACS analysis and measurement of cytokines. Local intestinal inflammatory changes were characterized by immunohistochemistry. Mortality was increased in CASP animals previously subjected to SID. Subclinical bacteremia occurred after SID, and an immunosuppressive milieu occurred secondary to SID just before the induction of CASP. Previous SID modified the pattern of intestinal inflammation induced by CASP. Subdiaphragmatic vagotomy had no influence on sepsis mortality in our model of postoperative peritonitis. Our results indicate a surgery-induced inflammation of the small intestine and the peritoneal cavity with bacterial translocation, which led to immune dysfunction and consequently to a more severe peritonitis.

McKittrick Wheelock Syndrome Treated by Transanal Minimally Invasive Surgery: A Single-Center Experience and Review of the Literature

INTRODUCTION

McKittrick Wheelock Syndrome (MKWS) is a rare syndrome characterized by secretory diarrhea, dehydration, prerenal acute kidney injury, and severe electrolyte abnormalities caused by a large hypersecretory villous adenoma located in the rectum or rectosigmoid junction. Transabdominal (laparoscopic) procedures are the most described procedures in the treatment of MKWS. We report an alternative surgical approach, transanal minimally invasive surgery (TAMIS), to solve this syndrome.

MATERIALS AND METHODS

All patients who underwent transanal endoscopic microsurgery or TAMIS were included in a prospectively collected database in our center. Between 1996 and 2015, 3 patients were found to have MKWS and treated by TAMIS. Demographics, characteristics of the adenoma, surgery-related data, and outcome were analyzed.

RESULTS

The first patient had a villous adenoma 0-12 cm from the anal verge. After TAMIS, she complained of a stenosis that was successfully treated by dilatation. The second patient had an impressive bulky tumor in the rectum. An endoscopic mucosal resection was attempted twice, but incompletely. Pathology analysis showed villous adenoma with high-grade dysplasia and intramucosal carcinoma. One year after TAMIS, a recurrence was detected and treated by an abdominal-perineal resection. A TAMIS was performed in the third patient because of a giant villous circular adenoma, but because of high mucus and fluid production, no proper overview could be obtained. Together with opening of the peritoneum, this prompted us to convert to a laparoscopic Hartmann procedure. Besides this technical difficulty, the patient recovered uneventful.

CONCLUSIONS

MKWS is a rare syndrome and missed diagnosis could result in life-threatening situations. Different endoscopic and surgical treatments are described to solve this syndrome. TAMIS should be considered as a rectum-preserving surgical treatment option for such extensive adenomas.

[Characteristics of postoperative peritonitis]

Postoperative peritonitis is still a life-threatening complication after abdominal surgery and approximately 10,000 patients annually develop postoperative peritonitis in Germany. Early recognition and diagnosis before the onset of sepsis has remained a clinical challenge as no single specific screening test is available. The aim of therapy is a rapid and effective control of the source of infection and antimicrobial therapy. After diagnosis of diffuse postoperative peritonitis surgical revision is usually inevitable after intestinal interventions. Peritonitis after liver, biliary or pancreatic surgery is managed as a rule by means of differentiated therapy approaches depending on the severity.

Electrolyte depletion syndrome (McKittrick-Wheelock syndrome) successfully treated by endoscopic submucosal dissection

A 66-year-old woman presented to us with malaise, anorexia and rectal mucous discharge, and her laboratory data showed severe hyponatremia, hypokalemia, hypochloremia and renal failure. Computed tomography revealed massive occupation of the rectum by a large tumor. Colonoscopy revealed a mucus-rich villous tumor in the rectum. As there were no other factors that could cause an electrolyte disorder, she was diagnosed with McKittrick-Wheelock syndrome (MWS). The current standard treatment for MWS is partial surgical colectomy. However, surgeries are invasive and postoperative complications sometimes become an issue. After confirming no signs of submucosal invasion of the tumor by magnifying chromoendoscopic examination, endoscopic submucosal dissection (ESD) was indicated. The tumor was completely removed en bloc without adverse events. The histology showed a mucosal adenocarcinoma containing a villous component, 24.5 x 17.0 cm in size. This removal dramatically improved the patient's symptoms and the electrolyte abnormalities without medication. Although several sessions of endoscopic balloon dilation were required to treat postoperative stricture, she has been symptom-free and had no recurrence for 4 years after treatment. We experienced a case of MWS treated by ESD instead of surgery. ESD should be feasible and beneficial for the treatment of MWS.

Balancing zinc deficiency leads to an improved healing of colon anastomosis in rats

BACKGROUND

In colorectal surgery, anastomotic leakage is a relevant complication. The aim of this study was to investigate whether intraperitoneally (i.p.) administered zinc improves the healing of colon anastomosis in rats.

MATERIALS AND METHODS

Male Wistar rats (66) received zinc-deficient diet for 21 days. To determine the effective dose of zinc which is necessary to compensate this deficiency, preliminary analysis in 30 rats were performed. In these rats, analysis by atom-absorption spectrophotometry revealed a dose of 1.0 mg zinc aspartate/kg body weight to be the compensatory dosage. In the remaining zinc-deficient rats (n= 36), a transverse colonic anastomosis was performed. Eighteen rats received either a zinc supplementation i.p. or 0.9% NaCl i.p. (n = 18; control group). On postoperative days 3, 5, and 14, the surface of the mucosal villi, expression of MMP 2, MMP 8, MMP 13, TIMP 1, as well as the collagen types I/III ratio were analyzed.

RESULTS

Protein expression of MMP 2 and MMP 8 was significantly higher in the anastomosis of the zinc group on day 3 and on day 5. The collagen types I/III ratio was significantly increased in the zinc group on days 5 and 14.

CONCLUSION

Balancing zinc deficiency benefits wound healing of colonic anastomosis qualitatively due to an increased collagen type I/III ratio. Surprisingly, these zinc supplements, however, increased the expression of MMP 2 and MMP 8 that are supposed to impair wound healing in case of an over-expression. Thus, further investigations are needed to elucidate the influence of zinc supplementation on regulation of MMPs.