Altered microperfusion at the rectal stump is predictive for rectal anastomotic leak

Evaluation of intestinal perfusion by ICG fluorescence imaging in laparoscopic colorectal surgery with DST anastomosis

BACKGROUND

Decreased blood perfusion is an important risk factor for postoperative anastomotic leakage (AL). Fluorescence imaging with indocyanine green (ICG) provides a real-time assessment of intestinal perfusion. This study evaluated the utility of ICG fluorescence imaging in determining the transection line of the proximal colon during laparoscopic colorectal surgery with double stapling technique (DST) anastomosis.

METHODS

This was a prospective single-institution study of 68 patients with left-sided colorectal cancers who underwent laparoscopic colorectal surgery between August 2013 and December 2014. After distal transection of the bowel, the specimen was extracted extracorporeally and then the mesentery was divided along the planned transection line determined by the surgeons' judgement under normal q. After ICG was injected intravenously, intestinal perfusion of the proximal colon was assessed in the fluorescent imaging mode. Intestinal perfusion was examined in relation to the patient-, tumor- and surgery-related variables using univariate and multivariate analyses.

RESULTS

ICG fluorescence imaging showed that intestinal perfusion was present at 3 mm (median) distal to the initially planned transection line. ICG fluorescence imaging resulted in a proximal change of the transection line by more than 5 mm in 18 patients (26.5 %) and, particularly, by more than 50 mm in 3 patients (4.4 %), compared with the initially planned transection line. Univariate analysis revealed that diabetes mellitus, anticoagulation therapy, preoperative chemotherapy and operative time were significantly associated with poor intestinal perfusion. Multivariate analysis identified anticoagulation therapy (P = 0.021) and preoperative chemotherapy (P = 0.019) as independent risk factors for poor intestinal perfusion. Three patients (4.5 %) with a change of transection line developed AL.

CONCLUSIONS

ICG fluorescence imaging is useful for determining the transection line in laparoscopic colorectal surgery with DST anastomosis. Anticoagulation therapy and preoperative chemotherapy are important risk factors for poor intestinal perfusion.

Colorectal anastomotic leakage can be predicted by abdominal aortic calcification on preoperative CT scans: A pilot study

BACKGROUND

There have been no solid data regarding whether patients with aortic calcification (AC) who have undergone colorectal surgery are at increased risk for anastomotic leakage. Our study aim to investigate the impact of AC on anastomotic leakage (AL) and postoperative morbidity after colorectal resection.

METHODS

This was a cohort study of 60 patients who were prospectively registered in a database. We evaluated the relationship between an aortic calcification score (ACS), measured on preoperative computed tomography (CT) imaging, and surgical complications in patients undergoing colorectal surgery.

RESULTS

ACS was strongly correlated with mortality rate. All three of the deceased patients were in the ACS-2 group (5%; P=0.021). The rate of AL was positively correlated with ACS; no leakage was found cases of ACS-0, with a rate of 18% in cases of ACS-1 and 44% in cases of ACS-2 (P=0.022). The consequences of AL were more serious according to the grade of ACS.

DISCUSSION

This study suggested that aortic calcification score is correlated with surgical outcomes, particularly anastomosis leakage, after colorectal surgery. These findings could provide useful tools for adapting surgical strategies by delaying colorectal anastomosis in high-risk patients.

Sidestream dark field imaging of the serosal microcirculation during gastrointestinal surgery

AIM

The study aimed to describe the serosal microcirculation of the human bowel using sidestream dark field imaging, a microscopic technique using polarized light to visualize erythrocytes through capillaries. We also compared its feasibility to the current practice of sublingual microcirculatory assessment.

METHOD

In 17 patients sidestream dark field measurements were performed during gastrointestinal surgery. Microcirculatory parameters like microvascular flow index (MFI), proportion of perfused vessels (PPV), perfused vessel density (PVD) and total vessel density (TVD) were determined for every patient, sublingually and on the bowel serosa.

RESULTS

Sixty measurements were done on the bowel of which eight (13%) were excluded, five owing to too much bowel peristalsis and three because of pressure artefacts. Image stability was in favour of sublingual measurements [pixel loss per image, bowel 145 (95% CI 126-164) vs sublingual 55 (95% CI 41-68); P < 0.001] and time to acquire a stable image [bowel 96 s (95% CI 63-129) vs. sublingual 46 s (95% CI 29-64); P = 0.013]. No difference in the MFI was observed [bowel 2.9 (interquartile range 2.87-2.95) vs sublingual 3.0 (interquartile range 2.91-3.0); P = 0.081]. There was a difference in the PPV [bowel 95% (95% CI 94-96) vs sublingual 97% (95% CI 97-99); P < 0.001], PVD [bowel 12.9 mm/mm2 (95% CI 11.1-14.8) vs sublingual 17.4 mm/mm2 (95% CI 15.6-19.1); P = 0.003] and the TVD [bowel 13.6 mm/mm2 (95% CI 11.6-15.6) vs sublingual 17.7 mm/mm2 (95% CI 16.0-19.4); P = 0.008].

CONCLUSION

Sidestream dark field imaging is a very promising technique for bowel microcirculatory visualization and assessment. It is comparable to sublingual assessment and the analysis produces a similar outcome with slightly differing anatomical features.

Hyperbaric oxygen therapy improves colorectal anastomotic healing

PURPOSE

Hyperbaric oxygen treatment (HBOT) has been found to improve the healing of poorly oxygenated tissues. This study aimed to investigate the influence of HBOT on the healing in ischemic colorectal anastomosis.

METHODS

Forty Wistar rats were randomly divided into a treatment group that received HBOT for 10 consecutive days (7 days before and 3 days after surgery), or in a control group, which did not receive the therapy. Colectomy with an ischemic anastomosis was performed in all rats. In each group, the rats were followed for 3 or 7 days after surgery to determine the influence of HBOT on anastomotic healing.

RESULTS

Five rats from each group died during follow-up. No anastomotic dehiscence was seen in the HBOT group, compared to 37.5 % and 28.6 % dehiscence in the control group on postoperative day (POD) 3 and 7, respectively. The HBOT group had a significantly higher bursting pressure (130.9 ± 17.0 mmHg) than the control group (88.4 ± 46.7 mmHg; p = 0.03) on POD 3. On POD 3 and POD 7, the adhesion severity was significantly higher in the control groups than in the HBOT groups (p < 0.005). Kidney function (creatinine level) of the HBOT group was significantly better than of the control group on POD 7 (p = 0.001). Interestingly, a significantly higher number of CD206+ cells (marker for type 2 macrophages) was observed in the HBOT group at the anastomotic area on POD 3.

CONCLUSION

Hyperbaric oxygen enhanced the healing of ischemic anastomoses in rats and improved the postoperative kidney function.

Is the intraoperative air leak test effective in the prevention of colorectal anastomotic leakage? A systematic review and meta-analysis

OBJECTIVE

The intra-operative air leak test (ALT) is a common intraoperative test used to identify mechanically insufficient anastomosis. This meta-analysis aims to determine whether ALT aids to the reduction of postoperative colorectal anastomotic leakage (CAL).

METHODS

A literature search was performed to select studies in acknowledged databases. Full text articles targeting ALT during colorectal surgery were included. Quality assessment, risk of bias, and the level-of-evidence of the inclusions were evaluated. ALT methodology, ALT(+) (i.e., leak observed during the test) rate, and postoperative CAL rate of the included studies were subsequently analyzed.

RESULTS

Twenty studies were included for analysis, in which we found substantial risks of bias. A lower CAL rate was observed in patients who underwent ALT than those did not; however, the difference was not significant (p = 0.15). The intraoperative ALT(+) rate greatly varied among the included studies from 1.5 to 24.7 %. ALT(+) patients possessed a significantly higher CAL rate than the ALT(-) patients (11.4 vs. 4.2 %, p < 0.001).

CONCLUSIONS

Based on the available evidence, performing an ALT with the reported methodology has not significantly reduced the clinical CAL rate but remains necessary due to a higher risk of CAL in ALT(+) cases. Unfortunately, additional repairs under current methods may not effectively decrease this risk. Results of this review urge a standardization of ALT methodology and effective methods to repair ALT(+) anastomoses.

Anastomotic leakage in rectal cancer surgery: The role of blood perfusion

Anastomotic leakage after anterior resection for rectal cancer remains a common and often devastating complication. Preoperative risk factors for anastomotic leakage have been studied extensively and are used for patient selection, especially whether to perform a diverting stoma or not. From the current literature, data suggest that perfusion in the rectal stump rather than in the colonic limb may be more important for the integrity of the colorectal anastomosis. Moreover, available research suggests that the mid and upper rectum is considerably more vascularized than the lower part, in which the posterior compartment seems most vulnerable. These data fit neatly with the observation that anastomotic leaks are far more frequent in patients undergoing total compared to partial mesorectal excision, and also that most leaks occur dorsally. Clinical judgment has been shown to ineffectively assess anastomotic viability, while promising methods to measure blood perfusion are evolving. Much interest has recently been turned to near-infrared light technology, enhanced with fluorescent agents, which enables intraoperative perfusion assessment. Preliminary data are promising, but large-scale controlled trials are lacking. With maturation of such technology, perfusion measurements may in the future inform the surgeon whether anastomoses are at risk. In high colorectal anastomoses, anastomotic revision might be feasible, while a diverting stoma could be fashioned selectively instead of routinely for low anastomoses.

Postoperative Hemodynamic Index Measurement With Miniaturized Dynamic Light Scattering Predicts Colorectal Anastomotic Healing

INTRODUCTION

Perioperative bowel perfusion (local hemodynamic index [LHI]) was measured with a miniaturized dynamic light scattering (mDLS) device, aiming to determine whether anastomotic perfusion correlates with the anastomotic healing process and whether LHI measurement assists in the detection of anastomotic leakage (AL) in colorectal surgery.

METHODS

A partial colectomy was performed in 21 male Wistar rats. Colonic and anastomotic LHIs were recorded during operation. On postoperative day (POD) 3, the rats were examined for AL manifestations. Anastomotic LHI was recorded before determining the anastomotic bursting pressure (ABP). The postoperative LHI measurements were repeated in 15 other rats with experimental colitis. Clinical manifestations and anastomotic LHI were also determined on POD3. Diagnostic value of LHI measurement was analyzed with the combined data from both experiments.

RESULTS

Intraoperative LHI measurement showed no correlation with the ABP on POD3. Postoperative anastomotic LHI on POD3 was significantly correlated with ABP in the normal rats (R(2) = 0.52; P < .001) and in the rats with colitis (R(2) = 0.63; P = .0012). Anastomotic LHI on POD3 had high accuracy for identifying ABP <50 mm Hg (Area under the curve = 0.86; standard error = 0.065; P < .001). A cutoff point of 1236 yielded a sensitivity of 100% and a specificity of 65%. On POD3, rats with LHIs <1236 had significantly higher dehiscence rates (40% vs 0%), more weight loss, higher abscess severity, and lower ABPs (P < .05); worse anastomotic inflammation and collagen deposition were also found in the histological examination.

CONCLUSION

Our data suggest that postoperative evaluation of anastomotic microcirculation with the mDLS device assists in the detection of AL in colorectal surgery.

Risk Factors for Dehiscence of Stapled Functional End-to-End Intestinal Anastomoses in Dogs: 53 Cases (2001-2012)

OBJECTIVE

To identify risk factors for dehiscence in stapled functional end-to-end anastomoses (SFEEA) in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 53) requiring an enterectomy.

METHODS

Medical records from a single institution for all dogs undergoing an enterectomy (2001-2012) were reviewed. Surgeries were included when gastrointestinal (GIA) and thoracoabdominal (TA) stapling equipment was used to create a functional end-to-end anastomosis between segments of small intestine or small and large intestine in dogs. Information regarding preoperative, surgical, and postoperative factors was recorded.

RESULTS

Anastomotic dehiscence was noted in 6 of 53 cases (11%), with a mortality rate of 83%. The only preoperative factor significantly associated with dehiscence was the presence of inflammatory bowel disease (IBD). Surgical factors significantly associated with dehiscence included the presence, duration, and number of intraoperative hypotensive periods, and location of anastomosis, with greater odds of dehiscence in anastomoses involving the large intestine.

CONCLUSION

IBD, location of anastomosis, and intraoperative hypotension are risk factors for intestinal anastomotic dehiscence after SFEEA in dogs. Previously suggested risk factors (low serum albumin concentration, preoperative septic peritonitis, and intestinal foreign body) were not confirmed in this study.

High arterial ligation and risk of anastomotic leakage in anterior resection for rectal cancer in patients with increased cardiovascular risk

AIM

Controversy still exists as to whether division of the inferior mesenteric artery close to the aorta influences the risk of anastomotic leakage after anterior resection for rectal cancer. This population-based study was carried out to evaluate the independent association between high arterial ligation and anastomotic leakage in patients with increased cardiovascular risk.

METHOD

All 2673 cases of registered anterior resection for rectal cancer from 2007 to 2010 were identified from the Swedish Colorectal Cancer Registry and cross-referenced with the Prescribed Drugs Registry, rendering a cohort of all patients with increased cardiovascular risk. Operative charts and registered data were reviewed for 722 patients. The association between high tie and anastomotic leakage, as quantified by ORs and 95% CIs, was evaluated in a logistic regression model, with adjustment for confounding, including assessment of interaction.

RESULTS

Symptomatic anastomotic leakage occurred in 12.3% (41/334) of patients in the high tie group and in 10.6% (41/388) in the low tie group. The use of high tie was not independently associated with a higher risk of anastomotic leakage (OR = 1.05; 95% CI: 0.61-1.84). In a post-hoc analysis, patients with a history of manifest cardiovascular disease and American Society of Anesthesiologists (ASA) score III-IV seemed to be at greater risk (OR = 3.66; 95% CI: 1.04-12.85).

CONCLUSION

In the present population-based, observational setting, high tie was not independently associated with an increased risk of symptomatic anastomotic leakage after anterior resection for rectal cancer. However, this conclusion may not hold for patients with severe cardiovascular disease.

Enhanced Reality and Intraoperative Imaging in Colorectal Surgery

Colorectal surgery is one of the most common procedures performed around the world with more than 600,000 operations each year in the United States, and more than a million worldwide. In the past two decades, there has been a clear trend toward minimal access and surgeons have embraced this evolution. Widespread adoption of advanced minimally invasive procedures is often limited by procedural complexity and the need for specific technical skills. Furthermore, the loss of 3D vision, limited overview of the surgical field, and diminished tactile sensation make major colorectal procedures more challenging and have an impact on the surgeons' learning curves. New technologies are emerging that can compensate for some of the sensory losses associated with laparoscopy. High-definition picture acquisition, 3D camera systems, and the use of biomarkers will allow improved identification of the target structures and help differentiate them from surrounding tissues. In this article, we describe some of the new technologies available and, in particular, focus on the possible implications of biomarkers and fluorescent laparoscopic imaging.

Indocyanine green-enhanced fluorescence to assess bowel perfusion during laparoscopic colorectal resection

Aims

Anastomotic leakage after colorectal surgery is a severe complication. One possible cause of anastomotic leakage is insufficient vascular supply. The aim of this study was to evaluate the feasibility and the usefulness of intraoperative assessment of vascular anastomotic perfusion in colorectal surgery using indocyanine green (ICG)-enhanced fluorescence.

Methods

Between May 2013 and October 2014, all anastomosis and resection margins in colorectal surgery were investigated using fluorescence angiography (KARL STORZ GmbH & Co. KG, Tuttlingen, Germany) intraoperatively to assess colonic perfusion prior to and after completion of the anastomosis, both in right and left colectomies.

Results

A total of 107 patients undergoing colorectal laparoscopic resections were enrolled: 40 right colectomies, 10 splenic flexure segmental resections, 35 left colectomies, and 22 anterior resections. In 90 % of cases, the indication for surgery was cancer and high ligation of vessels was performed. Based on the fluorescence intensity, the surgical team judged the distal part of the proximal bowel to be anastomosed insufficiently perfused in 4/107 patients (two anterior, one sigmoid and one segmental splenic flexure resections for cancer), and consequently, further proximal “re-resection” up to a “fluorescent” portion was performed. None of these patients had a clinical leak. The overall morbidity rate was 30 %; one patient undergoing right colectomy had an anastomotic leakage, apparently unrelated to ischemia; there were no clinical evident anastomotic leakages in colorectal resections including all low anterior resections.

Conclusions

ICG-enhanced fluorescent angiography provides useful intraoperative information about the vascular perfusion during colorectal surgery and may lead to change the site of resection and/or anastomosis, possibly affecting the anastomotic leak rate. Larger further randomized prospective trials are needed to validate this new technique.

Anterior Resection for Rectal Cancer and Visceral Blood Flow: An Explorative Study

BACKGROUND AND AIMS

Impaired blood perfusion may be implicated in anastomotic leakage after anterior resection for rectal cancer. We investigated whether high ligation of the inferior mesenteric artery or total mesorectal excision compromises visceral blood flow in the colonic limb and the rectal stump, respectively.

MATERIAL AND METHODS

A prospective cohort study was conducted in a university hospital setting. We used Laser Doppler flowmetry to evaluate the impact of level of tie on colonic limb perfusion and the extent of the mesorectal excision on the rectal blood flow. In the rectum, different quadrants were also assessed. The Mann-Whitney U test was used to compare mean blood flow ratios between groups.

RESULTS

Some 23 patients were recruited in a convenience sample during a period in 2012-2013. The mean blood flow ratio was not decreased after high tie compared to low tie surgery (1.71 vs 1.19; p = 0.28). Total mesorectal excision reduced the mean blood flow ratio in the rectum, as compared with partial mesorectal excision (0.76 vs 1.28; p = 0.14). This was especially pronounced in the posterior aspect of the rectum (0.66 vs 1.68; p = 0.02).

CONCLUSION

High tie ligation did not seem to decrease colonic limb perfusion, while total mesorectal excision may decrease rectal blood flow. The posterior quadrant of the rectum might be particularly vulnerable to the dissection involved in total mesorectal excision.

A Clinical Parameters-Based Model Predicts Anastomotic Leakage After a Laparoscopic Total Mesorectal Excision: A Large Study With Data From China

Anastomotic leakage after colorectal surgery is a major and life-threatening complication that occurs more frequently than expected. Intraoperative judgment in predicting potential leakage has shown extremely low sensitivity and specificity. The lack of a model for predicting anastomotic leakage might explain this insufficient judgment. We aimed to propose a clinical parameters-based model to predict anastomotic leakage after laparoscopic total mesorectal excision (TME).This study was a retrospective analysis of a prospectively designed colorectal cancer dataset. In total, 1968 patients with a laparoscopic TME were enrolled from November 1, 2010, to March 20, 2014. The independent risk factors for anastomotic leakage were identified, from which the parameters-based model for leakage was developed.Anastomotic leakage was noted in 63 patients (3.2%). Male sex, a low level of anastomosis, intraoperative blood loss, diabetes, the duration time of the surgery, and low temperature were significantly associated by the bivariate analysis and the Cochran-Mantel-Haenszel test with an increased risk. From these factors, the logistic regression model identified the following 4 independent predictors: male sex (risk ratio [RR] = 1.85, 95% confidence interval [CI]: 1.13-4.87), diabetes (RR = 2.08, 95% CI: 1.19-5.8), a lower anastomosis level (RR = 3.41, 95% CI: 1.17-6.71), and a high volume of blood loss (RR = 1.03, 95% CI: 1.01-1.05). The locally weighted scatterplot smoothing regression showed an anastomosis within 5 cm from the anus and intraoperative blood loss of >100 mL as the cutoff values for a significantly increased risk of leakage. Based on these independent factors, a parameters-based model was established by the regression coefficients. The high and low-risk groups were classified according to scores of 3-5 and 0-2, with leakage rates of 8.57% and 1.66%, respectively (P < 0.001).This parameters-based model could predict the risk of anastomotic leakage following laparoscopic rectal cancer. After further validation, this model might facilitate the intraoperative recognition of high-risk patients to perform defunctional stomas.

Vascular anatomy of the small intestine-a comparative anatomic study on humans and pigs

BACKGROUND

Porcine models are well established for studying intestinal anastomotic healing. In this study, we aimed to clarify the anatomic differences between human and porcine small intestines. Additionally, we investigated the influences of longitudinal and circular sutures on human small intestine perfusion.

METHODS

Intestines were obtained from human cadavers (n = 8; small intestine, n = 51) and from pigs (n = 10; small intestine, n = 60). Vascularization was visualized with mennige gelatin perfusion and high-resolution mammography. Endothelial cell density was analyzed with immunohistochemistry and factor VIII antibodies. We also investigated the influence of suture techniques (circular anastomoses, n = 19; longitudinal sutures, n = 15) on vascular perfusion.

RESULTS

Only human samples showed branching of mesenteric vessels. Compared to the pig, human vessels showed closer connections at the entrance to the bowel wall (p = 0.045) and higher numbers of intramural anastomoses (p < 0.001). Porcine main vessels formed in multifilament-like vessel bundles and displayed few intramural vessel anastomoses. Circular anastomoses induced a circular perfusion defect at the bowel wall; longitudinal anastomoses induced significantly smaller perfusion defects (p < 0.001). Both species showed higher vascular density in the jejunum than in the ileum (p < 0.001). Human samples showed similar vascular density within the jejunum (p = 0.583) and higher density in the ileum (p < 0.001) compared to pig samples.

CONCLUSION

The results showed significant differences between human and porcine intestines. The porcine model remains the standard for studies on anastomotic healing because it is currently the only viable model for studying anastomosis and wound healing. Nevertheless, scientific interpretations must consider the anatomic differences between humans and porcine intestines.

Application of fluorescence in robotic general surgery: review of the literature and state of the art

The initial use of the indocyanine green fluorescence imaging system was for sentinel lymph node biopsy in patients with breast or colorectal cancer. Since then, application of this method has received wide acceptance in various fields of surgical oncology, and it has become a valid diagnostic tool for guiding cancer treatment. It has also been employed in numerous conventional surgical procedures with much success and benefit to the patient. The advent of minimally invasive surgery brought with it a new use for fluorescence in helping to improve the safety of these procedures, particularly for single-site procedures. In 2010, a near-infrared camera was integrated into the da Vinci Si System, creating a combination of technical and minimally invasive advantages that have been embraced by several experienced surgeons. The use of fluorescence, although useful, is considered challenging. Only a few studies are currently available on the use of fluorescence in robotic general surgery, whereas many articles have focused on its application in open and laparoscopic surgery. Many of these reports describe promising and satisfactory results, although with some shortcomings. The purpose of this article is to review the current status of the use of fluorescence in general surgery and particularly its role in robotic surgery. We also review potential uses in the future.

Evaluation of the intestinal blood flow near the rectosigmoid junction using the indocyanine green fluorescence method in a colorectal cancer surgery

PURPOSE

It has been reported that some patients do not have an anastomosis of a marginal artery near the rectosigmoid junction, but the frequency of this condition and its clinical significance so far remain unclear. The aim of this study was to evaluate the blood flow at the marginal artery near the rectosigmoid junction.

METHODS

From January 2013 to January 2014, we enrolled consecutive patients with a preoperative diagnosis of left-sided colon cancer or rectal cancer who underwent surgery with lymph node dissection. During the operation, the blood flow through the point of origin of the last sigmoid arterial branch, originating from the inferior mesenteric artery, was interrupted, and the rectosigmoid junction was supplied by only the marginal artery. We injected indocyanine green intravenously and observed the blood flow using a near-infrared camera system.

RESULTS

A total of 119 consecutive patients were enrolled in this study. Sixty-eight patients (57.1 %) had a good anastomosis of the marginal artery near the rectosigmoid junction (type A). In 27 patients (22.7 %), a fluorescence border was recognized, but the fluorescence border diminished within 60 s (Type B). In 18 patients (15.1 %), delayed fluorescence was recognized over 60 s (type C), and 6 patients (5.0 %) had no fluorescence at all (type D). A mean length of 14.8 cm was found from the peritoneal reflection to fluorescence border of blood flow.

CONCLUSIONS

This study proves that cases without the anastomosis of the marginal artery of the rectosigmoid junction truly exist, using studies in living humans (UMIN000011186).

Functional outcome of autologous anorectal transplantation in an experimental model

BACKGROUND

Although anorectal transplantation is a challenging procedure, it is a promising option for patients who have completely lost anorectal function or in whom it failed to develop, as in congenital malformations. The paucity of animal models with which to test functional outcomes was addressed in this study of anorectal manometry in rats.

METHODS

Wistar rats were assigned randomly to four groups: orthotopic anorectal transplantation, heterotopic transplantation, sham operation, or normal control. Bodyweight and anal pressure were measured immediately before and after operation, and on postoperative days 7 and 14. ANOVA and Tukey's test were used to compare results for bodyweight, anal manometry and length of procedure.

RESULTS

Immediately after the procedure, mean(s.d.) anal pressure in the orthotopic group (n = 13) dropped from 31·4(13·1) to 1·6(13·1) cmH2 O (P < 0·001 versus both sham operation (n = 13) and normal control (n = 15)), with partial recovery on postoperative day 7 (14·9(13·9) cmH2 O) (P = 0·009 versus normal control) and complete recovery on day 14 (23·7(12·2) cmH2 O). Heterotopic rats (n = 14) demonstrated partial functional recovery: mean(s.d.) anal pressure was 26·9(10·9) cmH2 O before operation and 8·6(6·8) cmH2 O on postoperative day 14 (P < 0·001 versus both sham and normal control).

CONCLUSION

Orthotopic anorectal transplantation may result in better functional outcomes than heterotopic procedures. Surgical relevance Patients with a permanent colostomy have limited continence. Treatment options are available, but anorectal transplantation may offer hope. Some experimental studies have been conducted, but available data are currently insufficient to translate into a clinical option. This paper details functional outcomes in a rat model of anorectal autotransplantation. It represents a step in the translational research that may lead to restoration of anorectal function in patients who have lost or have failed to develop it.

Perfusion assessment in laparoscopic left-sided/anterior resection (PILLAR II): a multi-institutional study

BACKGROUND

Our primary objective was to demonstrate the utility and feasibility of the intraoperative assessment of colon and rectal perfusion using fluorescence angiography (FA) during left-sided colectomy and anterior resection. Anastomotic leak (AL) after colorectal resection increases morbidity, mortality, and, in cancer cases, recurrence rates. Inadequate perfusion may contribute to AL. The PINPOINT Endoscopic Fluorescence Imaging System allows for intraoperative assessment of anastomotic perfusion.

STUDY DESIGN

This is a prospective, multicenter, open-label, clinical trial that assessed the feasibility and utility of FA for intraoperative perfusion assessment during left-sided colectomy and anterior resection at 11 centers in the United States.

RESULTS

A total of 147 patients were enrolled, of whom 139 were eligible for analysis. Diverticulitis (44%), rectal cancer (25%), and colon cancer (21%) were the most prevalent indications for surgery. The mean level of anastomosis was 10 ± 4 cm from the anal verge. Splenic-flexure mobilization was performed in 81% and high ligation of the inferior mesenteric artery in 61.9% of patients. There was a 99% success rate for FA, and FA changed surgical plans in 11 (8%) patients, with the majority of changes occurring at the time of transection of the proximal margin (7%). Overall morbidity rates were 17%. The anastomotic leak rate was 1.4% (n = 2). There were no anastomotic leaks in the 11 patients who had a change in surgical plan based on intraoperative perfusion assessment with FA.

CONCLUSIONS

PINPOINT is a safe and feasible tool for intraoperative assessment of tissue perfusion during colorectal resection. There were no anastomotic leaks in patients in whom the anastomosis was revised based on inadequate perfusion with FA.

Intraoperative assessment of colorectal anastomotic integrity: a systematic review

BACKGROUND

Surgeons have attempted to minimize postoperative anastomotic complications by employing intraoperative tests and manoeuvres to assess colorectal anastomotic integrity. These have evolved over time with improvement in operative technology and techniques. This systematic review aims to examine the impact of such intraoperative assessments.

METHODS

A systematic review of studies assessing intraoperative anastomotic assessments and their impact on postoperative anastomotic complications was performed. Intraoperative measures undertaken as a result of intraoperative assessments and postoperative anastomotic complications were analysed.

RESULTS

37 Studies were identified. 13 studies evaluated basic mechanical patency tests, ten studies evaluated endoscopic visualisation techniques and 14 studies evaluated microperfusion techniques. Postoperative anastomotic complications were significantly lower in patients tested with basic mechanical patency tests compared to those untested (non-RCT: 4.1 vs. 8.1 %, p = 0.03, RCTs: 5.8 vs. 16.0 %, p = 0.024). There were no differences in postoperative anastomotic complications between tested and non-tested cohorts in non-randomised cohort studies evaluating endoscopic visualisation techniques. However, intraoperative measures taken after abnormal intraoperative tests may have reduced the number of postoperative complications. Perfusion analysis techniques are not in routine widespread clinical practice as yet, but newer techniques such as fluorescent dyes and imaging under near infrared light show technical feasibility.

CONCLUSIONS

Intraoperative colorectal anastomotic assessment has evolved together with advancement of technology in the surgical setting. Moderate benefit in terms of lower postoperative anastomotic complications has been shown with basic mechanical patency testing and more recently with intraoperative endoscopic visualisation of colorectal anastomoses. The next advance and possible introduction into routine practice may include the use of microperfusion techniques. The latest in this group of techniques, which utilise autofluorescent dyes such as Indocyanine green, hold great potential. Well-planned controlled studies or ideally, randomised controlled trials need to be conducted to further assess the benefit of these latest techniques.

Near-infrared (NIR) perfusion angiography in minimally invasive colorectal surgery

BACKGROUND

Anastomotic leakage is a devastating complication of colorectal surgery. However, there is no technology indicative of in situ perfusion of a laparoscopic colorectal anastomosis.

METHODS

We detail the use of near-infrared (NIR) laparoscopy (PinPoint System, NOVADAQ, Canada) in association with fluorophore [indocyanine green (ICG), 2.5 mg/ml] injection in 30 consecutive patients who underwent elective minimally invasive colorectal resection using the simultaneous appearance of the cecum or distal ileum as positive control.

RESULTS

The median (range) age of the patients was 64 (40-81) years with a median (range) BMI of 26.7 (20-35.5) kg/m(2). Twenty-four patients had left-sided resections (including six low anterior resections) and six had right-sided resections. Of the total, 25 operations were cancer resections and five were for benign disease [either diverticular strictures (n = 3) or Crohn's disease (n = 2)]. A high-quality intraoperative ICG angiogram was achieved in 29/30 patients. After ICG injection, median (range) time to perfusion fluorescence was 35 (15-45) s. Median (range) added time for the technique was 5 (3-9) min. Anastomotic perfusion was documented as satisfactory in every successful case and encouraged avoidance of defunctioning stomas in three patients with low anastomoses. There were no postoperative anastomotic leaks.

CONCLUSION

Perfusion angiography of colorectal anastomosis at the time of their laparoscopic construction is feasible and readily achievable with minimal added intraoperative time. Further work is required to determine optimum sensitivity and threshold levels for assessment of perfusion sufficiency, in particular with regard to anastomotic viability.

Optimizing perioperative hemodynamics: what is new?

PURPOSE OF REVIEW

Using perioperative goal-directed therapy (GDT) or peroperative hemodynamic optimization significantly reduces postoperative complications and risk of death in patients undergoing noncardiac major surgeries. In this review, we discuss the main changes in the field of perioperative optimization over the last few years.

RECENT FINDINGS

One of the key aspects that has changed in the last decade is the shift from invasive monitoring with pulmonary artery catheters (PACs) to less or minimally invasive monitoring systems. The evaluation of intravascular fluid volume deficits has also changed dramatically from the use of static indices to the assessment of fluid responsiveness using either dynamic indices or functional hemodynamic. Finally, attention has been directed toward more restrictive strategies of crystalloids as maintenance fluids.

SUMMARY

GDT is safe and more likely to tailor the amount of fluids given to the amount of fluids actually needed. This approach includes assessment of fluid responsiveness and, if necessary, the use of inotropes; moreover, this approach can be coupled with a restrictive strategy for maintenance fluids. These strategies have been increasingly incorporated into protocols for perioperative hemodynamic optimization in high-risk patients undergoing major surgery, resulting in more appropriate use of fluids, vasopressors, and inotropes.

The influence of fluorescence imaging on the location of bowel transection during robotic left-sided colorectal surgery

BACKGROUND

Hypoperfusion is an important risk factor for anastomotic leakage in colorectal surgery. This study was designed to evaluate the impact of fluorescence imaging on visualization of perfusion and subsequent change of transection line during left-sided robotic colorectal resections.

METHODS

Patients scheduled for robotic left-sided colon or rectal resections were enrolled in this prospective, multicenter study. Resections were performed as per each surgeon's preference. After complete colorectal mobilization, ligation of blood vessels, and distal transection of the bowel, the mesocolon was completely divided to the planned proximal or distal transection line, which was marked in white light. Indocyanine green was injected intravenously and the transection location(s) and/or distal rectal stump, if applicable, were re-assessed in fluorescent imaging mode. Imaging information, perioperative, and early postoperative outcomes were recorded. An independent video review of the surgeries was performed.

RESULTS

Data for 40 patients (20 female/20 male) with a mean age of 63.9 years and a mean body mass index of 27.6 kg/m(2) were analyzed. Fluorescence imaging resulted in a change of the proximal transection location in 40 % (16/40) of patients. There was one change in the distal transection location in a patient with benign disease. The use of fluorescence imaging took an average of 5.1 min of the mean overall operative room time of 232 min. Two patients (5 %) with a change in transection line developed an anastomotic leak at postoperative days 15 and 40.

CONCLUSION

Fluorescence imaging provides additional information during determination of transection location in left-sided colorectal procedures. This results in a significant change of transection location, particularly at the proximal transection site. Further research needs to be conducted with larger patient cohorts and in comparative design to determine actual effect on anastomotic leak rate.

Predictors of septic shock following anastomotic leak after major gastrointestinal surgery: An audit from a tertiary care institute

Background:

Anastomotic leak is a serious complication after major gastrointestinal surgery and majority of deaths occur due to septic shock. Therefore, the early identification of risk factors of septic shock may help reduce the adverse outcomes.

Objective:

The aim of this audit was to determine the predictors of septic shock in patients with anastomotic leak after major gastrointestinal surgery.

Design:

Retrospective, audit.

Materials and Methods:

The patients admitted in the gastrosurgical intensive care unit ICU) of our institute between September 2009 and April 2012 with anastomotic leakage after surgery were identified. The ICU charts were retrieved from the database to identify the patients progressing to septic shock. A comparison of risk factors was made between the patients who developed septic shock (septic shock group) against the patients who did not (non-septic shock group).

Results:

The study sample comprised of 103 patients with anastomotic leak, of which 72 patients developed septic shock. The septic shock group had a higher APACHE II score, lower MAP, and higher HR at the time of ICU admission. They received greater transfusion of packed red blood cells during their ICU stay. Septic shock was more common after pancreaticojejunostomy and hepaticojejunostomy leaks.

Conclusion:

Presence of malignancy, chronic obstructive pulmonary disease (COPD), packed red blood cell transfusion, bacteremia, and hepaticojejunostomy or pancreaticojejunostomy leaks were independent predictors of mortality and length of ICU stay. To the best of our knowledge there are no available studies in the literature on the predictors of risk factors of septic shock in patients with anastomotic leakage.

Compromised visceral circulation does not affect the outcome of colorectal surgery

PURPOSE

Anastomotic leakage is a serious complication after colorectal surgery, and many risk factors for this problem have so far been identified. The aim of this study was to assess the association between visceral arterial occlusive disease and anastomotic leakage.

METHODS

The preoperative abdominal computed tomography scans from all consecutive patients who underwent colorectal surgery with anastomosis in 2010 were retrospectively analyzed.

RESULTS

A total of 242 patients were included, with a median age of 65 years (interquartile range 55-74). Anastomotic leakage occurred in 14 % of cases (n = 34). The mortality rate was 3 % (n = 8). There was no association between atherosclerosis of the visceral or iliac arteries and anastomotic leakage. There was also no association between right-sided or left-sided resections and total occlusion of the superior or inferior mesenteric artery, respectively.

CONCLUSION

Asymptomatic visceral artery occlusive disease is not a risk factor for anastomotic leakage after colorectal surgery, and additional radiological imaging or percutaneous transluminal angioplasty for occluded visceral vessels is not indicated prior to colorectal surgery.

Do we really know why colorectal anastomoses leak?

INTRODUCTION

Colorectal anastomotic leak, a feared complication, results in significantly increased patient morbidity, mortality, and hospital resource utilization. The overall incidence of colorectal anastomotic leak is approximately 11% with increasing rate the closer the anastomosis is to the anal verge. Because surgeons are unable to reliably predict which anastomosis would fail, most will construct a diverting ileostomy for low colorectal anastomosis to circumvent the devastating complications of anastomotic failure. Despite extensive investigations on technical considerations of anastomosis construction, anastomotic leaks continue to occur at an unacceptably high rate.

DISCUSSION

In this review, we examine the major known risk factors and technical considerations that have been implicated as factors in leakage. Although surgical technique has evolved over the past several decades with the advent of newer surgical staplers, laparoscopy, and robotics, we have not witnessed a decrease in the incidence of colorectal anastomotic leaks suggesting that the fundamental pathogenesis of anastomotic leak remains unknown. Among the factors contributing to anastomotic healing, intestinal bacteria remains largely overlooked even though compelling evidence exist that intraluminal microbes could play a major role in pathogenesis of anastomotic leak. Further investigation focusing on intestinal microbes could be one such avenue for uncovering the elusive cause of colorectal anastomotic leak.

Anastomotic stability and wound healing of colorectal anastomoses sealed and sutured with a collagen fleece in a rat peritonitis model

BACKGROUND/OBJECTIVE

Anastomotic insufficiency is associated with increased morbidity and mortality. A collagen fleece that supports anastomosis is effective for preventing anastomosis insufficiency. The objective of this study was to compare between the stability of sutured anastomoses and that of anastomoses sealed with a thrombin/fibrinogen-coated collagen fleece in a rat peritonitis model.

METHODS

In 72 male Wistar rats, peritonitis was induced with a specially prepared human fecal solution. Surgery at the rectosigmoid junction was performed 24-36 hours later. The different anastomotic techniques used were circular sutured anastomoses, semicircular sutured anastomosis and closure of the anterior wall with collagen patch, and complete closure with a collagen fleece. Bursting pressure, histology of anastomosis, mRNA expression of collagen types I and III, matrix metalloproteinase-13, and vascular endothelial growth factor (VEGF) were investigated after 24 hours, 72 hours, and 120 hours.

RESULTS

All animals developed peritonitis of comparable severity. There were no differences in bursting pressures between the three suture techniques after 24 hours, 72 hours, or 120 hours. Anastomoses sealed with a collagen fleece appeared to be slightly less stable only at 24 hours, whereas they appeared to be more stable than semisutured or fully sutured anastomoses at 72 hours and 120 hours. Sealing with a collagen fleece was associated with an increase in granulation tissue, higher mRNA levels for collagen types I and III, and higher VEGF compared to sutured anastomoses.

CONCLUSION

The use of a thrombin/fibrinogen-coated collagen fleece showed similar efficacy to conventional sutures in colorectal anastomoses in the presence of peritonitis inflammation, and may provide additional benefits due to an increase in mature granulation tissue.

Identifying important predictors for anastomotic leak after colon and rectal resection: prospective study on 616 patients

OBJECTIVE

The purpose of this study was to identify patient, clinical, and surgical factors that may predispose patients to anastomotic leak (AL) after large bowel surgery.

BACKGROUND

Anastomotic leak is still one of the most devastating complications following colorectal surgery. Knowledge about factors predisposing patients to AL is vital to its early detection, decision making for surgical time, managing preoperative risk factors, and postoperative complications.

METHODS

This was a prospective observational, quality improvement study in a cohort of 616 patients undergoing colorectal resection in a single institution with the main outcome being AL within 30 days postoperatively. Some of the predictor variables were age, sex, Charlson Comorbidity Index (CCI), radiation and chemotherapy, immunomodulator medications, albumin, preoperative diagnoses, surgical procedure(s), surgical technique (laparoscopic vs open), anastomotic technique (staple vs handsewn), number of major arteries ligated at surgery, surgeon's experience, presence of infectious condition at surgery, intraoperative adverse events, and functional status using 36-Item Short Form General Health Survey.

RESULTS

Of the 616 patients, 53.4% were female. The median age of the patients was 63 years and the mean body mass index was 25.9 kg/m. Of them, 80.3% patients had laparoscopic surgery and 19.5% had open surgery. AL occurred in 5.7% (35) patients. In multivariate analysis, significant independent predictors for leak were anastomoses less than 10 cm from the anal verge, CCI of 3 or more, high inferior mesenteric artery ligation (above left colic artery), intraoperative complications, and being of the male sex.

CONCLUSIONS

Multiple risk factors exist that predispose patients to ALs. These risk factors should be considered before and during the surgical care of colorectal patients.

Risk factors for anastomotic leakage following anterior resection for colorectal cancer: the effect of epidural analgesia on occurrence

PURPOSE

The effect of thoracic epidural analgesia (TEA) on anastomotic leakage (AL) after anterior resection for colorectal cancer is controversial. The aim of this study was to evaluate the risk factors including TEA for the occurrence of AL after anterior resection for colorectal cancer.

METHODS

This retrospective study included 1,312 patients with colorectal cancer who underwent anterior resection between 2000 and 2011 at the Cancer Center, Sun Yat-sen University. Univariate and multivariate logistics analyses were performed to determine the risk factors, including TEA, for AL. Additionally, we evaluated the effect of TEA on outcome parameters.

RESULTS

AL occurred in 118 (9 %) of the 1,312 patients. In univariate analysis, the American Society of Anesthesiologists (ASA) score, history of hypertension, episodes of hypotension, anastomosis technique, tumor localization, anesthesia duration, and perioperative blood transfusion were significant risk factors for AL. Multivariate analysis showed that ASA (P = 0.001), perioperative blood transfusion (P < 0.001), anastomosis technique (P = 0.019), anesthesia duration (P = 0.033), and tumor localization (P = 0.009) were independent factors affecting AL. TEA had no effect on the occurrence of AL (P = 0.451) in multivariate analysis. However, the length of hospital stay was shortened by the use of TEA (P < 0.001).

CONCLUSIONS

The results of this retrospective study suggest that TEA has no effect on the occurrence of AL. However, TEA may be recommended to shorten the length of hospital stay.

Procalcitonin and C-reactive protein as early predictors of anastomotic leak in colorectal surgery: a prospective observational study

BACKGROUND

Although the early diagnosis of anastomotic leak is a key point in reducing its clinical consequences, in daily practice, anastomotic leak diagnosis is often late.

OBJECTIVE

The aim of this study was to determine whether procalcitonin and C-reactive protein are good predictors of anastomotic leak in colorectal surgery.

DESIGN

This is a prospective observational study.

SETTINGS

This study was conducted by a specialized colorectal multidisciplinary team of a tertiary teaching hospital.

PATIENTS

A series of 205 consecutive patients who underwent elective colorectal surgery in a specialized unit was prospectively analyzed. The following data were collected: demographic, surgical, ASA class, POSSUM, and morbidity. During the first 5 postoperative days, procalcitonin, C-reactive protein, leukocytes, platelets, and vital signs were evaluated daily.

INTERVENTIONS

Daily assessment of clinical variable and serological data were conducted in the first 5 postoperative days.

MAIN OUTCOME MEASURES

The primary outcome measure was the area under the curve at receiving operating characteristic curve analysis of the different variables in relation to the anastomotic leak.

RESULTS

Anastomotic leak was detected in 17 (8.3%) patients; 11(5.4%) of the patients had a major anastomotic leak (need for drainage or reoperation). None of the variables evaluated were shown to be reliable in the early detection of anastomotic leak, considering both minor and major (maximum area under the curve <0.80). In contrast, when considering only major anastomotic leaks, procalcitonin and C-reactive protein were reliable predictors on postoperative days 3 to 5 (p < 0.0001, area under the curve >0.80). The best combination was procalcitonin at postoperative day 5 (area under the curve = 0.86), with a cutoff of 0.31 ng/mL, resulting in a 100% sensitivity, 72% specificity, 100% negative predictive value, and 17% positive predictive value.

LIMITATIONS

Only symptomatic patients were investigated to rule out anastomotic leakage.

CONCLUSIONS

Procalcitonin and C-reactive protein are both reliable predictors of major anastomotic leak after colorectal resection, although procalcitonin is more accurate. Raised procalcitonin and C-reactive protein serum concentration on postoperative days 3 to 5 renders necessary a careful evaluation of the patient before discharge.

Local ischaemia does not influence anastomotic healing: an experimental study

The role of local ischaemia in the pathogenesis of colorectal anastomotic leakage (AL) is not known. This study investigates the role of local ischaemia caused by sutures in an experimental colonic anastomosis model. 36 mice were assigned to three types of anastomosis, all using running sutures; in the first group 5 stitches were used, in the second group 12 stitches were used, and in the third group at least 30 stitches were used. After 7 days the mice were re-operated, signs of AL were scored, and coronal sections of the anastomosis were histologically analyzed. The distribution of weight was not significantly different between the three groups. Mortality was 44% and not significantly different between the groups (group 1: 5/12, group 2: 4/12, and group 3: 7/12, p = 0.72). Faecal and purulent AL were observed in 6 animals in group 1, 2 in group 2, and 3 in group 3 (group 1: 50%, group 2: 17%, and group 3: 25%, p = 0.19). The distance between the two colonic edges (group 1: 0.51 μm, group 2: 1.34 μm, and group 3: 0.53 μm, p = 0.18), the diameter of the lumen at the site of the anastomosis (group 1: 2.92 μm, group 2: 4.06 μm, and group 3: 3.2 μm, p = 0.9), and the largest diameter of the lumen proximally to the anastomosis (group 1: 2.05 μm, group 2: 3.1 μm, and group 3: 2.6 μm, p = 0.25) were not different between the groups. Histological parameters of wound healing were not significantly different for the three groups. In this study no macroscopic and microscopic differences were observed between colon anastomosis with 5 stitches versus 12 and >30 stitches. This might indicate that local ischaemia does not negatively influence colonic wound healing.

The use of indocyanine green fluorescence to assess anastomotic perfusion during robotic assisted laparoscopic rectal surgery

BACKGROUND

Decreased blood perfusion at an intestinal anastomosis may contribute to postoperative anastomotic leak (AL) resulting in substantial morbidity and mortality. Near-infrared (NIR) laparoscopy in conjunction with indocyanine green (ICG) allows for visualization of the microcirculation before formation of the anastomosis, thereby allowing the surgeon to choose the point of transection at an optimally perfused area.

METHODS

This is a retrospective case-control analysis examining the effectiveness of NIR + ICG in reducing the rate of AL after low anterior resection (LAR) for rectal cancer. Records of patients undergoing robot-assisted LAR for rectal cancer with and without ICG were analyzed for the years 2011 and 2012.

RESULTS

Among the 40 patients who underwent robotic LAR, NIR + ICG was used in 16 cases (41 %). Male patients accounted for the majority of cases in both groups (74 %). The median level of the anastomosis was 3.5 cm in the NIR + ICG group and 5.5 cm in the control group. There was no difference in the use of diverting ileostomy. In 3 patients (19 %), the use of NIR + ICG resulted in revision of the proximal bowel (colonic) transection point before formation of the anastomosis. The distal transection point was never revised. The rate of AL in the NIR + ICG group was 6 % versus 18 % in control group.

CONCLUSIONS

ICG fluorescence may play a role in anastomotic tissue perfusion assessment and affect the AL rate. Larger prospective studies are needed to further validate this novel technology.

Intra-operative transanal near infrared imaging of colorectal anastomotic perfusion: a feasibility study

AIM

Anastomotic dehiscence is a devastating complication. Inadequate blood supply is felt to be the prevailing cause. This study describes the use of near infrared imaging to evaluate transanally anastomotic tissue perfusion following low anterior resection.

METHOD

Twenty patients undergoing low anterior resection for benign and malignant disease were studied. After completing the anastomosis, indocyanine green (ICG) was injected via a peripheral intravenous catheter. An endoscopic near infrared imaging system (Pinpoint, Novadaq, Canada) was then used transanally to visualize mucosal perfusion of the colon, rectum and the anastomotic staple line.

RESULTS

All patients underwent a technically successful ICG angiogram. The angiogram was abnormal in four patients. Two of these had a protective loop ileostomy and showed no sign of anastomotic breakdown. The other two patients were found on CT scan to have a peri-anastomotic collection consistent with anastomotic leakage. Both were managed conservatively with resolution.

CONCLUSION

This study confirms that transanal ICG angiography is feasible and provides imaging of mucosal and anastomotic blood flow. The technique warrants further study in a larger group of patients to assess its ability to identify defects in tissue perfusion that may lead to anastomotic breakdown.

The C-seal trial: colorectal anastomosis protected by a biodegradable drain fixed to the anastomosis by a circular stapler, a multi-center randomized controlled trial

Background

Anastomotic leakage is a major complication in colorectal surgery and with an incidence of 11% the most common cause of morbidity and mortality. In order to reduce the incidence of anastomotic leakage the C-seal is developed. This intraluminal biodegradable drain is stapled to the anastomosis with a circular stapler and prevents extravasation of intracolonic content in case of an anastomotic dehiscence.

The aim of this study is to evaluate the efficacy of the C-seal in reducing anastomotic leakage in stapled colorectal anastomoses, as assessed by anastomotic leakage leading to invasive treatment within 30 days postoperative.

Methods

The C-seal trial is a prospective multi-center randomized controlled trial with primary endpoint, anastomotic leakage leading to re-intervention within 30 days after operation. In this trial 616 patients will be randomized to the C-seal or control group (1:1), stratified by center, anastomotic height (proximal or distal of peritoneal reflection) and the intention to create a temporary deviating ostomy. Interim analyses are planned after 50% and 75% of patient inclusion. Eligible patients are at least 18 years of age, have any colorectal disease requiring a colorectal anastomosis to be made with a circular stapler in an elective setting, with an ASA-classification < 4. Oral mechanical bowel preparation is mandatory and patients with signs of peritonitis are excluded. The C-seal student team will perform the randomization procedure, supports the operating surgeon during the C-seal application and achieves the monitoring of the trial. Patients are followed for one year after randomization en will be analyzed on an intention to treat basis.

Discussion

This Randomized Clinical trial is designed to evaluate the effectiveness of the C-seal in preventing clinical anastomotic leakage.

Trial registration

NTR3080

Complications of colorectal anastomoses: leaks, strictures, and bleeding

Intestinal anastomosis is an essential part of surgical practice, and with it comes the inherent risk of complications including leaks, strictures, and bleeding, which result in significant morbidity and occasional mortality. Understanding the myriad of risk factors and the strength of the data helps guide a surgeon as to the safety of undertaking an operation in which a primary anastomosis is to be considered. This article reviews the risk factors, management, and outcomes associated with anastomotic complications.

Effects of low cardiopulmonary reserve on pancreatic leak following pancreaticoduodenectomy

Background

Postoperative complications are increased in patients with reduced cardiopulmonary reserve undergoing major surgery. Pancreatic leak is an important contributor to postoperative complications and death following pancreaticoduodenectomy. The aim of this study was to determine whether reduced cardiopulmonary reserve was a risk factor for pancreatic leak.

Methods

All patients who underwent pancreaticoduodenectomy between January 2006 and July 2010 were identified from a prospectively held database. Data analysis was restricted to those who underwent cardiopulmonary exercise testing during preoperative assessment. Pancreatic leak was defined as grade A, B or C according to the International Study Group on Pancreatic Fistula definition. An anaerobic threshold (AT) cut-off value of 10·1 ml per kg per min was used to identify patients with reduced cardiopulmonary reserve. Univariable and multivariable analyses were performed to identify other risk factors for pancreatic leak.

Results

Some 67 men and 57 women with a median age of 66 (range 37–82) years were identified. Low AT was significantly associated with pancreatic leak (45 versus 19·2 per cent in patients with greater cardiopulmonary reserve; P = 0·020), postoperative complications (70 versus 38·5 per cent; P = 0·013) and prolonged hospital stay (29·4 versus 17·5 days; P = 0·001). On multivariable analysis, an AT of 10·1 ml per kg per min or less was the only independent factor associated with pancreatic leak.

Conclusion

Low cardiopulmonary reserve was associated with pancreatic leak following pancreaticoduodenectomy. AT seems a useful tool for stratifying the risk of postoperative complications.

Smoking is a major risk factor for anastomotic leak in patients undergoing low anterior resection

AIM

To examine modifiable risk factors for anastomotic leak in patients undergoing low anterior resection.

METHOD

In total 233 patients undergoing low anterior resection for benign and malignant disease over a 10-year period at a single surgical unit were identified from a prospective database. The relationships between anastomotic leak and 17 variables were examined, including patient demographics, operative technique, tumour pathology, preoperative physiological function and smoking status.

RESULTS

The majority (91%) of operations were carried out for rectal cancers, and 24 procedures (10%) were performed with laparoscopic assistance. The overall anastomotic leak rate was 14% (33/233). Patients with anastomotic leak had higher 30-day mortality (6%vs 1%, P<0.05) and stayed significantly longer in hospital (median 23 vs 10 days, P<0.001). On multivariate analysis, current smokers (OR 3.68, 95% CI 1.38-9.82, P=0.009) and patients with evidence of metastatic malignant disease (OR 3.43, 95% CI 1.29-9.13, P=.013) were at increased risk of anastomotic leak.

CONCLUSION

Smoking and the presence of metastatic disease are major risk factors for the development of anastomotic leak following low anterior resection.

Intraoperative blood pressure changes as a risk factor for anastomotic leakage in colorectal surgery

PURPOSE

Anastomotic leakage is a serious complication after colorectal surgery. Pre- and intraoperative factors may contribute to failure of colorectal anastomosis. In this study we have tried to determine risk factors for anastomotic leakage, with special emphasis on intraoperative blood pressure changes.

METHODS

During a 24-month period, patients receiving a colorectal anastomosis were prospectively evaluated. For each patient preoperative characteristics, intraoperative adverse events and surgical outcome data were collected. Blood pressure changes were calculated as a relative decrease (>25% and >40%) from preoperative baseline values.

RESULTS

During the study period, 285 patients underwent colorectal surgery with an anastomosis. Fifteen patients developed an anastomotic leakage (5.3%). All patients who developed a leakage had a left-sided procedure (P < 0.001). When blood loss was more than 250 mL (P = 0.003) or an intraoperative adverse event occurred (P = 0.050), the risk for developing an anastomotic leakage was significantly increased. A preoperative high diastolic blood pressure of ≥90 mmHg (P = 0.008) and severe intraoperative hypotension [>40% decrease in diastolic blood pressure (P = 0.049)] were identified as univariate risk factors for anastomotic leakage.

CONCLUSIONS

The development of an anastomotic leakage after colorectal surgery is related to surgical, patient and anaesthetic risk factors. A high preoperative diastolic blood pressure and profound intraoperative hypotension combined with complex surgery, marked by a blood loss of ≥250 mL and the occurrence of intraoperative adverse events, is associated with an increased risk of developing anastomotic leakage.

Intraoperative contrast-enhanced sonography of bowel blood flow: preliminary experience

OBJECTIVES

The potential to predict, and therefore avoid, anastomotic failure has eluded generations of colon and rectal surgeons to date. A reliable, reproducible method of assessing bowel blood flow therefore would be of enormous potential clinical relevance. To our knowledge, intraoperative contrast-enhanced sonography of the bowel has not been performed previously. We present our study assessing the feasibility of using contrast-enhanced sonography to study bowel perfusion intraoperatively.

METHODS

We studied 8 patients (4 male and 4 female) with an age range of 52 to 81 years who underwent colorectal surgery (right hemicolectomies, n = 3; Hartmann procedure, n = 1; anterior resections, n = 2; and bowel resections with ileocolic anastomoses, n = 2). A 5-mL bolus of a sulfur hexafluoride contrast agent solution was injected before and after vascular ligation with simultaneous noncompression ultrasound scanning directly over the large bowel. The patients were followed clinically to assess for leaks. Contrast-enhanced sonographic time-intensity curves were generated for the time to peak and maximum amplitude.

RESULTS

Moderate interobserver agreement was shown for the time to peak (κ = 0.50) and maximum amplitude (κ = 0.42), and moderate intraobserver agreement was shown for the time to peak (κ= 0.53) and maximum amplitude (κ= 0.53). No significant differences were shown between the time to peak (P = .28) and maximum amplitude (P = .49) for the preligation and postligation scans.

CONCLUSIONS

To our knowledge, intraoperative contrast-enhanced sonography of the bowel has not been performed previously. We have shown the technique to be feasible with good intraobserver and interobserver agreement. Further work is ongoing to optimize the technique and assess its use in predicting anastomotic breakdown.

Elevated serum C-reactive protein as a predictive factor for anastomotic leakage in colorectal surgery

BACKGROUND

C-reactive protein (CRP) has been used as an indicator of postoperative complications in abdominal surgery. Its short half-life makes it a reliable marker of the systemic inflammatory response secondary to a surgical procedure or to the appearance of complications, rapidly returning to normal values with the recovery of the patient.

AIM

To demonstrate the value of sequential serum determinations of postoperative C-reactive protein (CRP) and white blood cell counts (WBC) in the identification of increased risk of anastomotic leakage after colorectal surgery.

METHODS

We reviewed the daily postoperative serum CRP and white blood cell counts in 173 patients who underwent surgery for colorectal disease with anastomosis, between January 2008 and October 2009. Patients with anastomotic leakage (Group A, n = 24) were compared to patients without leakage (Group B, n = 149). Patients with ongoing infections before surgery or with acquired postoperative infections other than leakage were excluded. Mean pre- and postoperative values of CRP and WBC were compared.

RESULTS

The diagnosis of anastomotic leakage was made between the 4th and 11th postoperative day (POD; mean 7th POD). The daily average values of serum CRP were significantly higher in group A starting at the 2nd POD and remained significantly elevated until the diagnosis of leakage (p = 0.003). The cut-off value of 140 mg/L on the 3rd POD maximized the sensitivity (78%) and specificity (86%) of serum CRP in assessing the risk of leakage. Comparison of postoperative serum WBC values did not show any significant differences between the two groups until the 6th POD.

CONCLUSION

According to these results, an early and persistent elevation of CRP after colorectal surgery with anastomosis, is a marker of anastomotic leakage. A cut-off value > 140 mg/L on POD3 maximizes sensitivity and specificity.

The influence of fecal diversion and anastomotic leakage on survival after resection of rectal cancer

BACKGROUND

We analyzed factors associated with the occurrence of anastomotic leakage (AL) and its impact on long-term survival in patients who have undergone resection for rectal cancer. We also investigated the effect of fecal diversion on survival.

METHOD

Clinical data of patients who received surgery for rectal cancer were reviewed. The difference in AL incidence among different groups was compared and survival rates were calculated. Cox's proportional hazards model was used to compare survival in patients who developed AL or received diversion stoma with those who did not.

RESULTS

Of 999 patients who received resection and anastomosis, 53 patients experienced AL. Multivariate analysis revealed advanced age (P = 0.009) and operative method (P = 0.002) were independent risk factors for AL. Anastomotic leakage was an independent risk factor for overall recurrence (HR 2.30; 95% CI 1.12-4.73). Anastomotic leakage and fecal diversion were independent prognostic factors of overall survival (P = 0.002 and P < 0.001, respectively), cancer-specific survival (P = 0.002 and P < 0.001, respectively), and disease-free survival (P < 0.001, respectively).

CONCLUSIONS

Patients who are older and have anastomosis at the anorectal junction or dentate line have an increased risk of AL. A diversion stoma does not appear to decrease the incidence of anastomotic leakage, but may decrease the need of reoperation when leakage occurred. Anastomotic leakage and fecal diversion are independent prognostic factors of overall, cancer-specific, and disease-free survival.

High tie in anterior resection for rectal cancer confers no increased risk of anastomotic leakage

BACKGROUND

It is controversial whether division of the inferior mesenteric artery close to the aorta influences the risk of anastomotic leakage, especially in the elderly and unfit. This population-based study was carried out to evaluate the independent association between a high arterial ligation and anastomotic leakage in anterior resection for rectal cancer.

METHODS

All patients who had anterior resection for rectal cancer from 2007 to 2009 inclusive were identified in the Swedish Colorectal Cancer Registry. The association between high tie and anastomotic leakage was evaluated in a logistic regression model, with adjustment for confounders. Stratification was performed for co-morbidity as judged by the American Society of Anesthesiologists (ASA) classification.

RESULTS

Symptomatic anastomotic leakage occurred in 81 (9·9 per cent) of 818 patients with a high tie and 108 (9·8 per cent) of 1101 without. Overall, the use of a high tie was not associated with a higher risk of anastomotic leakage (odds ratio (OR) 1·00, 95 per cent confidence interval 0·72 to 1·39). There was no increased risk in patients classifed as ASA grade I or II (OR 0·97, 0·69 to 1·35), or in those graded ASA III or IV (OR 1·26, 0·58 to 2·75).

CONCLUSION

In the present population-based setting, use of a high tie was not associated with an increased rate of symptomatic anastomotic leakage.

Effects of oxidative stress on mitochondrial content and integrity of human anastomotic colorectal dehiscence: a preliminary DNA study

BACKGROUND

Anastomotic dehiscence is one of the most severe complications of colorectal surgery. Gaining insight into the molecular mechanisms responsible for the development of anastomotic dehiscence following colorectal surgery is important for the reduction of postoperative complications.

OBJECTIVE

Based on the close relationship between surgical stress and oxidative stress, the present study aimed to determine whether a correlation exists between increased levels of reactive oxygen species and colorectal anastomotic dehiscence.

METHODS

Patients who underwent surgical resection for colorectal cancer were divided into three groups: patients with anastomotic dehiscence (group 1); patients without dehiscence who underwent neoadjuvant radiochemotherapy (group 2); and patients without anastomotic dehiscence who did not undergo neoadjuvant radiochemotherapy (group 3). Quantitative polymerase chain reaction and real-time polymerase chain reaction assays were performed to measure nuclear DNA and mitochondrial DNA (mtDNA) content, and possible oxidative damage to nonmalignant colon and rectal tissues adjacent to the anastomoses.

RESULTS

mtDNA content was reduced in the colon tissue of patients in groups 1 and 2. Rectal mtDNA was found to be more damaged than colonic mtDNAs in all groups. The 4977 bp common deletion was observed in the mtDNA of tissues from both the colon and rectum of all patients.

DISCUSSION

Patients in groups 1 and 2 were more similar to one another than to group 3, probably due to higher levels of reactive oxygen species in the mitochondria; the greater damage found in the rectum suggests that dehiscence originates primarily from the rectal area.

CONCLUSIONS

The present study of mtDNA analyses of normal human colon and rectal tissues from patients with colorectal cancer is among the first of its kind.

How to assess intestinal viability during surgery: A review of techniques

Objective and quantitative intraoperative methods of bowel viability assessment are essential in gastrointestinal surgery. Exact determination of the borderline of the viable bowel with the help of an objective test could result in a decrease of postoperative ischemic complications. An accurate, reproducible and cost effective method is desirable in every operating theater dealing with abdominal operations. Numerous techniques assessing various parameters of intestinal viability are described by the studies. However, there is no consensus about their clinical use. To evaluate the available methods, a systematic search of the English literature was performed. Virtues and drawbacks of the techniques and possibilities of clinical application are reviewed. Valuable parameters related to postoperative intestinal anastomotic or stoma complications are analyzed. Important issues in the measurement and interpretation of bowel viability are discussed. To date, only a few methods are applicable in surgical practice. Further studies are needed to determine the limiting values of intestinal tissue oxygenation and flow indicative of ischemic complications and to standardize the methods.