Timing and outcome of right- vs left-sided colonic anastomotic leaks: Is there a difference?

BACKGROUND: Anastomotic leaks (AL) contribute to postoperative mortality, prolonged hospitalization, and increased health care costs. While left-sided AL (LAL) are well described in the literature, there is a paucity of studies on outcomes and management of right-sided AL (RAL). This study aimed to compare the timing of RAL versus LAL, and the variable diagnosis, management and outcomes of RAL versus LAL. We hypothesized that the timing of RAL may be later compared to LAL and may result in worse overall outcomes. METHODS: Patients who underwent curative intent surgery for neoplastic disease from January 1995 to December 2015 were included. Patients that underwent an anastomosis below the peritoneal reflection, neoadjuvant treatment, fecal diversion, previous colectomy/anastomosis, multiple anastomoses, and patients with inflammatory bowel disease or hereditary colorectal cancer syndromes were excluded. Patient demographics, neoplastic data, operative data, time to AL, methods utilized for diagnosis of AL, and management of AL were collected. The primary endpoint was timing of AL, and secondary endpoints were management and outcome based on RAL versus LAL. RAL and LAL were analyzed and compared using Chi-squared and categorical variables were expressed as number (percentage) and continuous variables expressed as median (interquartile range). RESULTS: A total of 2223 patients underwent oncologic resection for colonic neoplasia (1457 right sided and 766 left sided anastomoses). 67% of patients were male and median age was 69 years (range, 34-91). There were 48 total AL events (2.16%): 26 RAL (1.78%) and 22 LAL (2.87%). There was no statistical difference in leak rates between RAL and LAL and no difference in time to diagnosis or management (Table 1). RAL had significantly decreased operative time (p = 0.016), decreased intraoperative blood loss (p = 0.002), and increased diagnosis by CT/plain radiograph (p = 0.04). All patients that underwent surgery for leak had some form of fecal diversion performed. Morbidity and mortality were comparable between groups (p = 0.70; p = 1.0). CONCLUSIONS: This study found overall very low AL rates with comparable timing of RAL and LAL, and no difference in management or outcome of RAL vs. LAL. These findings are informative for patient and surgeon expectations before and after surgery and when AL is suspected.

Use of Fluorescein Isothiocyanate-Inulin as a Marker for Intestinal Ischemic Injury.

BACKGROUND: Intestinal ischemia is observed in conditions such as mesenteric ischemia, or during traumatic events such as intestinal transplantation. Intestinal ischemia leads to pathophysiologic disruptions that present as increased fluid secretion into the intestinal lumen. We propose a novel method to detect real-time ischemic injury that is used in an in vitro model applicable to intestinal transplantation. STUDY DESIGN: Small intestine segments from rats were procured. The segments were attached to customized perfusion chambers. Both intestines were perfused on the vascular side with a Ringer buffer solution. The experimental buffer solution was bubbled with 100% nitrogen to mimic ischemia. Both lumens were perfused with 3 mL HEPES-Ringer solution containing 50 µM fluorescein isothiocyanate (FITC)-inulin. Intraluminal samples were collected at 15-minute intervals to measure FITC-inulin concentration using a nanofluorospectrophotometer. Intestinal tissue samples were processed and evaluated by a blinded pathologist using the Park/Chiu scoring system for grading intestinal ischemia. RESULTS: Samples collected from the ischemic intestine showed a significant decrease in FITC-inulin fluorescence compared with the control intestine, indicating enhanced fluid secretion. Histopathologic samples from the experimental arm exhibited higher scores of ischemic injury in comparison with the control arm, confirming the FITC-inulin as a correlation to ischemia. CONCLUSIONS: Fluorescein isothiocyanate-inulin can be used as a real-time volume marker to monitor the ischemic state of intestinal tissue. A positive correlation between the degree of fluid shift and presence of ischemic injury. The changes in fluorescence signal provide a potential selective method to measure real-time fluid changes inside an intestinal graft to evaluate viability.

Extracorporeal Hypothermic Perfusion Device for Intestinal Graft Preservation to Decrease Ischemic Injury During Transportation.

INTRODUCTION: The small intestine is one of the most ischemia-sensitive organs used in transplantation. To better preserve the intestinal graft viability and decrease ischemia-reperfusion injury, a device for extracorporeal perfusion was developed. We present the results for the first series of perfused human intestine with an intestinal perfusion unit (IPU). METHODS: Five human intestines were procured for the protocol. (1) An experimental segment was perfused by the IPU delivering cold preservation solution to the vascular and luminal side continually at 4 ºC for 8 h. (2) Control (jejunum and ileum) segments were preserved in static cold preservation. Tissue samples were obtained for histopathologic grading according to the Park/Chiu scoring system (0 = normal, 8 = transmural infarction). RESULTS: Jejunal experimental segments scored 2.2 with the Park/Chiu system compared to the control segments, which averaged 3.2. Overall scoring for ileum experimental and control segments was equal with 1.6. CONCLUSION: This data presents proof of concept that extracorporeal intestinal perfusion is feasible. The evidence shows that the IPU can preserve the viability of human intestine, and histopathologic evaluation of perfused intestine is favorable. Our early results can eventually lead to expanding the possibilities of intestinal preservation.

A new method to measure intestinal secretion using fluorescein isothiocyanate-inulin in small bowel of rats.

BACKGROUND: Small intestine ischemia can be seen in various conditions such as intestinal transplantation. To further understand the pathologic disruption in ischemia-reperfusion injury, we have developed a method to measure fluid changes in the intestinal lumen of rats. METHODS: Two 10-cm rat intestine segments were procured, connected to the terminal apertures of a perfusion device, and continuously infused with 3 mL of HEPES solution (control solution) containing 50 µM of fluorescein isothiocyanate (FITC)-inulin. The perfusion device consists of concentric chambers that contain the perfused bowel segments, which are maintained at 37°C via H2O bath. The individual chamber has four apertures as follows: two fill and/or drain the surrounding HEPES solution on the blood side of the tissue. The others provide flow of HEPES solution containing FITC-inulin through the lumens. The experimental intestine was infused with the same solution with 100 µM of Forskolin. A pump continuously circulated solutions at 6 mL/min. Samples were collected at 15-min intervals until 150 min and were measured by the nanoflourospectrometer. RESULTS: A mean of 6-µM decrease in the FITC-inulin concentration in the Forskolin-treated experimental intestine was observed in comparison with that in the control intestine. The FITC-inulin count dilution in the experimental intestine is a result of an increase of fluid secretion produced by the effect of Forskolin, with P values <0.0001. CONCLUSIONS: We demonstrate that it is possible to measure luminal fluid changes over time using our new modified perfusion system along with FITC-inulin to allow real-time determinations of fluid and/or electrolyte movement along the small intestine.