Clinical review: Healing in gastrointestinal anastomoses, Part I

Postoperative non-steroidal anti-inflammatory drug use and oncological outcomes of rectal cancer

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to suppress the inflammatory response after surgery and are often used for pain control. This study aimed to investigate NSAID use after radical surgical resection for rectal cancer and long-term oncological outcomes.

METHODS

A cohort of patients who underwent anterior resection for rectal cancer between 2007 and 2013 in 15 hospitals in Sweden was investigated retrospectively. Data were obtained from the Swedish Colorectal Cancer Registry and medical records; follow-up was undertaken until July 2019. Patients who received NSAID treatment for at least 2 days after surgery were compared with controls who did not, and the primary outcome was recurrence-free survival. Cox regression modelling with confounder adjustment, propensity score matching, and an instrumental variables approach were used; missing data were handled by multiple imputation.

RESULTS

The cohort included 1341 patients, 362 (27.0 per cent) of whom received NSAIDs after operation. In analyses using conventional regression and propensity score matching, there was no significant association between postoperative NSAID use and recurrence-free survival (adjusted hazard ratio (HR) 1.02, 0.79 to 1.33). The instrumental variables approach, including individual hospital as the instrumental variable and clinicopathological variables as co-variables, suggested a potential improvement in the NSAID group (HR 0.61, 0.38 to 0.99).

CONCLUSION

conventional modelling did not demonstrate an association between postoperative NSAID use and recurrence-free survival in patients with rectal cancer, although an instrumental variables approach suggested a potential benefit.

The incidence, risk factors, and new prediction score for fluorescence abnormalities of near-infrared imaging using indocyanine green in laparoscopic low anterior resection for rectal cancer

PURPOSE

Several studies have reported the efficacy of near-infrared imaging using indocyanine green in laparoscopic low anterior resection (LAR), but a detailed examination of its fluorescence abnormalities is still insufficient. The purpose of this study was to clarify the incidence of fluorescence abnormalities and to create a new prediction score in laparoscopic LAR.

METHODS

This was a retrospective, multicenter study that included patients with rectal cancer who underwent laparoscopic LAR from September 2014 to November 2018.

RESULTS

A total of 336 patients were included. The transection line was changed due to fluorescence abnormalities in 5.4% (18/336) of cases, and the median length of additional resection was 70 mm. Anastomotic leakage of Clavien-Dindo grade ≥ II occurred in 6.0% (20/336). The gender and the intraoperative pre-planned proximal margin (IpPM) were significant factors for fluorescence abnormalities. We devised the fluorescence abnormality prediction score (FAPS) derived from the gender, IpPM, and tumor height from the anal verge (TumorAV). The area under the curve of the FAPS was 0.784 (95% CI: 0.677-0.891). When the cutoff was 4, the sensitivity was 0.833, and the specificity was 0.626. The preoperative pre-planned proximal margin (PpPM) was calculated as follows: PpPM (mm) = 189 (mm) - TumorAV (mm) + 61 × Male (1/0). The proximal margin should be set to be larger than the PpPM to avoid fluorescence abnormalities.

CONCLUSION

The incidence of fluorescence abnormalities in laparoscopic LAR was 5.4%. If the FAPS is used, the PpPM may be set from the viewpoint of the blood perfusion.

TRIAL REGISTRATION

Japanese Clinical Trials Registry: UMIN000032654 ( http://www.umin.ac.jp/ctr/index.htm ).

The assessment of perioperative risk factors of anastomotic leakage after intestinal surgeries; a prospective study

Background

Anastomotic leaks (AL) are among the most serious complications due to the substantial impact on the quality of life and mortality. Inspite of the advance in diagnostic tools such as laboratory tests and radiological adjuncts, only moderate improvement has been recorded in the rate of detected leaks. The purpose of the research was to assess the perioperative risk factors for AL.

Methods

This study was achieved at MUH and MIH/Egypt within the period between January 2016 and January 2019 for the candidates who underwent bowel anastomosis for small intestinal (except duodenal one) and colorectal pathology. The collected data were analyzed using SPSS of V-26.

Results

This study included 315 cases, among them, 27 cases (8.57%) developed AL. The percentage of covering stoma was significantly higher in the non-leakage group vs leakage one (24.3% vs 11.1% respectively). lower albumin, operative timing, perforation, and covering stoma were shown as significant risk factors for leakage, but with multivariate analysis for these factors, the emergency operation, and serum albumin level was the only independent risk factors that revealed the significance consequently (p = 0.043, p = 0.015). The analysis of different predictors of AL on the third day showed that the cut-off point in RR was 29 with 83% sensitivity and 92% specificity in prediction of leakage, the cut-off point in RR was 118 with 74% sensitivity and 87% specificity in prediction of leakage and the cut-off point in CRP was 184.7 with 82% sensitivity and 88% specificity in prediction of AL and all had statistically significant value.

Conclusions

The preoperative serum albumin level and the emergency operations are independent risk factors for anastomotic leakage. Moreover, leakage should be highly suspected in cases with rising respiratory rate, heart rate, and CRP levels.

Multilayered Human Skeletal Muscle Myoblast Sheets Promote the Healing Process After Colonic Anastomosis in Rats

Colorectal anastomotic leakage is one of the most feared and fatal complications of colorectal surgery. To date, no external coating material that can prevent anastomotic leakage has been developed. As myoblasts possess anti-inflammatory capacity and improve wound healing, we developed a multilayered human skeletal muscle myoblast (HSMM) sheet by periodic exposure to supraphysiological hydrostatic pressure during repeated cell seeding. We assessed whether the application of an HSMM sheet can promote the healing process after colonic anastomosis. Partial colectomy and insufficient suturing were employed to create a high-risk colo-colonic anastomosis model in 60 nude rats. Rats were divided into a control group (n = 30) and an HSMM sheet group (n = 30). Macroscopic findings, anastomotic bursting pressure, and histology at the colonic anastomotic site were evaluated on postoperative day (POD) 3, 5, 7, 14, and 28. The application of an HSMM sheet significantly suppressed abscess formation at the anastomotic site compared to the control group on POD3 and 5. The anastomotic bursting pressure in the HSMM sheet group was higher than that in the control group on POD3 and 5. Inflammatory cell infiltration in the HSMM sheet group was significantly suppressed compared to that in the control group throughout the time course. Collagen deposition in the HSMM sheet group on POD3 was significantly abundant compared to that in the control group. Regeneration of the mucosa at the colonic anastomotic site was promoted in the HSMM sheet group compared to that in the control group on POD14 and 28. Immunohistochemical analysis demonstrated that surviving cells in the HSMM sheet gradually decreased with postoperative time and none were detected on POD14. These results suggest that the application of a multilayered HSMM sheet may prevent postoperative colonic anastomotic leakage.

Does intraoperative indocyanine green fluorescence angiography decrease the incidence of anastomotic leakage in colorectal surgery? A systematic review and meta-analysis

BACKGROUND

Colorectal anastomoses in patients with colorectal cancer carry a high risk of leakage. Indocyanine green fluorescence angiography (ICG-FA) is a new technique that allows surgeons to assess the blood perfusion of the anastomosis during operation. This meta-analysis aimed to evaluate whether ICG-FA could prevent anastomotic leakage (AL) in colorectal surgery.

METHODS

Four databases (PubMed, Embase, Web of Science, and Cochrane Library) were searched to identify suitable literatures until March 2020 that compared AL rates between intraoperative use and non-use of ICG-FA in colorectal surgery for cancer. The Review Manager 5.3 software was used to perform the statistical analysis. Evaluation of articles quality and analysis for publication bias were also conducted.

RESULTS

Thirteen studies of 4037 patients were included in the meta-analysis. The study included 1806 patients in the ICG group and 2231 patients in the control group. The pooled incidence of AL in ICG group was 3.8% compared with 7.8% in control group. There was a significant difference in AL rate with or without use of ICG-FA (OR 0.44; 95% CI 0.33-0.59; P < 0.00001). Reoperation rates were 2.6% and 6.9% in ICG and control groups, respectively. Application of intraoperative ICG-FA was associated with a lower risk of reoperation (OR 0.39; 95% CI 0.16-0.94; P = 0.04). Overall complication rate was 15.6% in the ICG group compared with 21.2% in the control group. Overall complications were significantly reduced when using ICG-FA (OR 0.62; 95% CI 0.47-0.82; P = 0.0008). Mortality rate was not statistically different with or without the use of ICG-FA (OR 1.22; 95% CI 0.20-7.30; P = 0.83).

CONCLUSION

The results revealed that ICG-FA reduced risks of AL, reoperation, and overall complications for colorectal cancer patients undergoing colorectal surgery. Well-designed RCTs are needed to confirm the usefulness of intraoperative ICG-FA for preventing surgical complications like AL and reoperation.

Intestinal anastomotic healing models during experimental colitis

BACKGROUND

Anastomotic leakage represents a major complication following resections in colorectal surgery. Among others, intestinal inflammation such as in inflammatory bowel disease is a significant risk factor for disturbed anastomotic healing. Despite technical advancements and several decades of focused research, the underlying mechanisms remain incompletely understood. Animal experiments will remain the backbone of this research in the near future. Here, instructions on a standardized and reproducible murine model of preoperative colitis and colorectal anastomosis formation are provided to amplify research on anastomotic healing during inflammatory disease.

METHODS

We demonstrate the combination of experimental colitis and colorectal anastomosis formation in a mouse model. The model allows for monitoring of anastomotic healing during inflammatory disease through functional outcomes, clinical scores, and endoscopy and histopathological examination, as well as molecular analysis.

DISCUSSION

Postoperative weight loss is used as a parameter to monitor general recovery. Functional stability can be measured by recording bursting pressure and location. Anastomotic healing can be evaluated macroscopically from the luminal side by endoscopic scoring and from the extraluminal side by assessing adhesion and abscess formation or presence of dehiscence. Histologic examination allows for detailed evaluation of the healing process.

CONCLUSION

The murine model presented in this paper combines adjustable levels of experimental colitis with a standardized method for colorectal anastomosis formation. Extensive options for sample analysis and evaluation of clinical outcomes allow for detailed research of the mechanisms behind defective anastomotic healing.

Validation of quantitative assessment of indocyanine green fluorescent imaging in a one-vessel model

Objectives

Evaluation of intestinal perfusion remains subjective and depends on the surgeon´s individual experience. Intraoperative quality assessment of tissue perfusion with indocyanine green (ICG) fluorescence using a near-infrared camera system has been described in different ways and for different indications. The aim of the present study was to evaluate fluorescent imaging (FI) in the quantitative assessment of intestinal perfusion in a gastric tube model in pigs and to compare the results to results obtained with florescent microspheres (FM), the gold standard for tissue perfusion.

Methods

Seven pigs (56.0±3.0 kg), both males and females, underwent gastric tube formation after transection and ligation of the gastric arteries, except the right gastroepiploic artery, to avoid collateral blood flow.

After baseline assessment (T0), hypotension (T1) was induced by propofol (Karampinis et al 2017) (< 60 mmHg). Then, propofol was paused to obtain normotension (T2, Mean arterial pressure (MAP) 60–90 mmHg). Finally, hypertension (T3, MAP>90 mmHg) was induced by norepinephrine.

Measurements were performed in three regions of interest (ROIs) under standardized conditions: the fundus (D1), corpus (D2), and prepyloric area (D3). Hemodynamic parameters and transit-time flow measurement (TTFM) in the right gastroepiploic artery were continuously assessed. FI, FM and the partial pressure of tissue oxygen (TpO₂) were quantified in each ROI.

Results

The study protocol could successfully be performed during stable hemodynamics. Flow in the gastroepiploic artery measured by transit time flow measurement (TTFM) was related to hemodynamic changes between the measurements, indicating improved blood flow with increasing MAP. The distal part of the gastric tube (D1) showed significantly (p<0.05) impaired perfusion compared to the proximal parts D3 and D2 using FM. ICG-FI also showed the highest values in D3 and the lowest values in D1 at all hemodynamic levels (T1-T3; p<0,05).

Conclusion

Visual and quantitative assessment of gastric tube perfusion is feasible in an experimental setting using ICG-FI. This might be a promising tool for intraoperative assessment during visceral surgery in the future.

Quantification of fluorescence angiography: Toward a reliable intraoperative assessment of tissue perfusion - A narrative review

BACKGROUND

Accurate intraoperative assessments of tissue perfusion are essential in all forms of surgery. As traditional methods of perfusion assessments are not available during minimally invasive surgery, novel methods are required. Here, fluorescence angiography with indocyanine green has shown promising results. However, to secure objective and reproducible assessments, quantification of the fluorescent signal is essential (Q-ICG). This narrative review aims to provide an overview of the current status and applicability of Q-ICG for intraoperative perfusion assessment.

RESULTS

Both commercial and custom Q-ICG software solutions are available for intraoperative use; however, most studies on Q-ICG have performed post-operative analyses. Q-ICG can be divided into inflow parameters (ttp, t0, slope, and T_1/2max) and intensity parameters (Fmax, PI, and DR). The intensity parameters appear unreliable in clinical settings. In comparison, inflow parameters, mainly slope, and T_1/2max have had superior clinical performance.

CONCLUSION

Intraoperative Q-ICG is clinically available; however, only feasibility studies have been performed, rendering an excellent usability score. Q-ICG in a post-operative setting could detect changes in perfusion following a range of interventions and reflect clinical endpoints, but only if based on inflow parameters. Thus, future studies should include the methodology outlined in this review, emphasizing the use of inflow parameters (slope or T_1/2max), a mass-adjusted ICG dosing, and a fixed camera position.

Risk of postoperative complications among ulcerative colitis patients treated preoperatively with vedolizumab: a matched case-control study

Background

Although biologic agents have revolutionized the medical management of severe ulcerative colitis (UC), there is considerable controversy regarding adverse effects of vedolizumab on surgical outcomes. We evaluated 30-day postoperative morbidity in UC patients undergoing abdominal colectomy (AC) treated with vedolizumab before surgery.

Methods

From 2007 to 2017, 285 patients were enrolled in prospectively maintained database evaluating the role of clinical, serologic markers with clinical phenotypes in UC. The patients treated with vedolizumab within 12 weeks of AC was queried, then matched 1:3:3 into 3 preoperative treatment groups based on age, gender and surgical treatment of UC; ileal pouch-anal anastomosis (IPAA) with ileostomy vs total colectomy with end stoma: a) vedolizumab (n = 25); b) anti-tumor necrosis factor (anti-TNF) (n = 74); and c) no biologics (n = 54). Thirty-day postoperative complications among patient groups were compared.

Results

The 3 patient groups were well-matched in other characteristics including disease duration, disease extent, medication history and preoperative serological data. There were no significant differences in the overall incidence of postoperative complications among patients treated preoperatively with vedolizumab, anti-TNFs, or no biologics (44% vs. 45% vs. 37%; p = 0.67). Although there was no significant difference between patient cohorts in infectious complications (p = 0.20), postoperative ileus (POI) was significantly more common among the vedolizumab group (n = 9; 36%) compared to anti-TNF (n = 12; 16%) or no biologics (n = 5; 9%) (p = 0.01). Multivariable analysis showed that vedolizumab treatment prior to surgery was an independent risk factor for POI (OR: 5.16, 95% CI; 1.71–15.52; p = .004).

Conclusion

Although preoperative vedolizumab exposure did not influence the rate of overall 30-day postoperative complications, vedolizumab tends to increase incidence of POI.

Impact of intraoperative indocyanine green fluorescence angiography on anastomotic leakage after laparoscopic sphincter-sparing surgery for malignant rectal tumors

PURPOSE

Whether indocyanine green fluorescence angiography (ICG-FA) during rectal surgery is effective in reducing anastomotic leakage remains unclear. This study aimed to investigate the effect of intraoperative ICG-FA on anastomotic leakage after sphincter-sparing surgery for malignant rectal tumors.

METHODS

This was a retrospective, single-center cohort study conducted on 852 consecutive patients who underwent laparoscopic sphincter-sparing surgery from January 2007 to June 2017 at our institution. The incidence of anastomotic leakage was compared between patients who underwent ICG-FA to determine the proximal resection margin and those in whom this technique was not performed, using logistic regression analysis, including propensity score.

RESULTS

A total of eight patients were excluded (one patient with previous low anterior resection and seven patients who underwent simultaneous resection for other primary cancers), resulting in 844 patients being analyzed. Before propensity score matching, 141 patients (16.7%) who underwent ICG-FA were compared with 703 patients (83.3%) in whom ICG-FA was not performed. The incidence of anastomotic leakage was 2.8% (4/141) in the ICG-FA group and 12.4% (87/703) in the control group (p = 0.001). After propensity score matching (n = 420), the patient characteristics between the two groups were well balanced, and the incidence of anastomotic leakage was 2.8% (4/141) in the ICG-FA group and 13.6% (38/279) in the control group (p = 0.001). Logistic regression analyses using propensity score showed that patients who underwent ICG-FA had significantly lower odds of anastomotic leakage.

CONCLUSION

Intraoperative ICG-FA is a promising method to reduce anastomotic leakage after laparoscopic rectal surgery.

Anastomotic healing in a rat model of peritonitis after non-steroidal anti-inflammatory drug administration

The tissue inflammatory response can influence the outcome of anastomotic healing. Anastomotic leakage represents a dreadful complication after gastrointestinal surgery, in particular sepsis and intra-abdominal infections impair the restorative process of colic anastomoses. It has been debated whether the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) is a risk factor for dehiscence, since many patients receive NSAIDs in the early postoperative period. Our aim was, for the first time, to analyze the morpho-functional effects of postoperative administration of two commonly used NSAIDs, Diclofenac and Ketorolac, on the healing process of colo-colic anastomoses constructed under condition of fecal peritonitis in a rat model. Sixty adult male rats underwent two surgical procedures: peritonitis induction and colo-colic anastomosis, and were divided into three groups: 20 rats received saline; 20 rats 4 mg/kg Diclofenac and 20 rats 5 mg/kg Ketorolac. We assessed anastomosis strength, morphological features of tissue wound healing, immunohistochemical metalloproteinase 9 (MMP9) expression and collagen deposition and content by Sirius red staining and hydroxyproline level. We found no significant difference in bursting pressure, collagen content and organization and morphological features between the groups, except a significantly reduced presence of inflammatory cells and MMP9 expression in the groups treated with NSAIDs. Our findings showed that Diclofenac and Ketorolac administration did not affect post-surgical healing and did not increase the leakage risk of colo-colic anastomoses during peritonitis.

Key clinical applications for indocyanine green fluorescence imaging in minimally invasive colorectal surgery

Near-infrared indocyanine green (ICG) fluorescence imaging has gained solid acceptance over the last years, and rightly so, as this technology has so much to offer, especially in the field of minimally invasive surgery. Firm evidence from ongoing and future studies will hopefully transform many of the applications of ICG fluorescence into the standard of care for our patients. This review examines the current status of ICG fluorescence for assessment of bowel perfusion, lymphatic mapping as well as intraoperative localisation of ureter in light of the published academic literature in English.

Safety and Feasibility of a Lower-Cost Stapler in Bariatric Surgery

BACKGROUND

Laparoscopic staplers are integral to bariatric surgery. Their pricing significantly impacts the overall cost of procedures. An independent device company has designed a stapler handle and single-use reloads for cross-compatibility and equivalency with existing manufacturers, at a lower cost.

OBJECTIVES

We aim to demonstrate non-inferior function and cross-compatibility of a newly introduced stapler handle and reloads compared to our institution's current stapling system in a large animal survival study.

SETTING

University-affiliated animal research facility, USA.

METHODS

Matched small bowel anastomoses were created in four pigs, one with each stapler (a total of two per animal). After 14 days, investigators blinded to stapler type evaluated the anastomoses grossly and microscopically. Each anastomosis was scored on multiple measures of healing. Individual parameters were added for a global "healing score."

RESULTS

Clinical stapler function and gross quality of anastomoses were similar between stapler groups. Individual scores for anastomotic ulceration, reepithelialization, granulation tissue, mural healing, eosinophilic infiltration, serosal inflammation, and microscopic adherences were also statistically similar. The mean "healing scores" were equal. While this study was underpowered for subtle differences, safe and reliable performance in large animals still supports the feasibility of introducing new devices into human use.

CONCLUSIONS

The new stapler system delivers a similar technical performance and is cross-compatible with currently marketed stapling devices. An equivalent quality device at a lower price point should enable case cost reduction, helping to maintain hospital case margin and procedure value in the face of potentially declining reimbursement. This device may provide a safe and functional alternative to currently used laparoscopic surgical staplers.

Reconstructive Surgery for Intestinal Failure

BACKGROUND

Intestinal failure (IF) in the adult is the result of a wide spectrum of disease. Acute mesenteric ischemia, postoperative short bowel due to a complicative course, and Crohn's disease are major causes of IF. Reconstructive surgery in the context of IF comprises a spectrum of procedures including stoma takedown, reversal of laparostomies, and closure of enteric fistulas.

METHODS

This article is based on a PubMed-based literature search and personal experience in adult patients with IF.

RESULTS

This review summarizes therapeutic options of reconstructive surgery in adult patients focusing on the main reasons of IF such as mesenteric ischemia, complicative previous surgery, and Crohn's disease. Indications and contraindications are discussed as well as the optimal time point of reconstructive surgery.

CONCLUSION

This overview summarizes surgical aspects in a special cohort of patients with a rare disease entity necessitating an interdisciplinary approach.

Hypoxia-adaptive pathways: A pharmacological target in fibrotic disease?

Wound healing responses are physiological reactions to injuries and share common characteristics and phases independently of the injured organ or tissue. A major hallmark of wound healing responses is the formation of extra-cellular matrix (ECM), mainly consisting of collagen fibers, to restore the initial organ architecture and function. Overshooting wound healing responses result in unphysiological accumulation of ECM and collagen deposition, a process called fibrosis. Importantly, hypoxia (oxygen demand exceeds supply) plays a significant role during wound healing responses and fibrotic diseases. Under hypoxic conditions, cells activate a gene program, including the stabilization of hypoxia-inducible factors (HIFs), which induces the expression of HIF target genes counteracting hypoxia. In contrast, in normoxia, so-called HIF-prolyl hydroxylases (PHDs) oxygen-dependently hydroxylate HIF-α, which marks it for proteasomal degradation. Importantly, PHDs can be pharmacologically inhibited (PHI) by so-called PHD inhibitors. There is mounting evidence that the HIF-pathway is continuously up-regulated during the development of tissue fibrosis, and that pharmacological (HIFI) or genetic inhibition of HIF can prevent organ fibrosis. By contrast, initial (short-term) activation of the HIF pathway via PHI during wound healing seems to be beneficial in several models of inflammation or acute organ injury. Thus, timing and duration of PHI and HIFI treatment seem to be crucial. In this review, we will highlight the role of hypoxia-adaptive pathways during wound healing responses and development of fibrotic disease. Moreover, we will discuss whether PHI and HIFI might be a promising treatment option in fibrotic disease, and consider putative pitfalls that might result from this approach.

Remote computer-assisted analysis of ICG fluorescence signal for evaluation of small intestinal anastomotic perfusion: a blinded, randomized, experimental trial

BACKGROUND

Indocyanine green fluorescence imaging (ICG-FI) may be used to visualize intestinal perfusion prior to anastomosis. Methods for quantification of the fluorescence signal are required to ensure an objective evaluation. The aim of this study was to evaluate a method for quantification of relative perfusion and to investigate the correlation between the perfusion level and the anastomotic strength.

METHOD

This blinded, randomized, experimental trial included twenty pigs. Each pig received three small intestinal anastomoses with 30%, 60%, or 100% perfusion, respectively. The perfusion levels were determined relative to healthy intestine using ICG-FI. Ischemia was induced by mesenteric ligation and the perfusion level of each anastomosis was determined using a software-based analysis of the fluorescence signal. On postoperative day 5, the anastomoses were subjected to tensile strength test and histopathological assessment.

RESULTS

No anastomotic leakage occurred. The tensile strength of the 30% perfusion group was 9.09 N, which was significantly lower than the 60% perfusion group (11.5 N) and the 100% perfusion group (12.9 N). The difference between the 60% perfusion group and the 100% perfusion group was not significant. The histopathological assessment showed no significant differences between perfusion groups.

CONCLUSIONS

A reduction in blood supply to 30%, as determined by ICG-FI, in small intestinal anastomoses was necessary to demonstrate a decrease in tensile strength.

Assessment of a Vacuum-Based Intra-Colonic Diverting Device: A Preclinical Study

Purpose. Anastomotic leak is the main complication after low colorectal anastomosis. Defunctioning ileostomy is therefore recommended, which carries its own morbidity. The aim of this study was to assess the technical feasibility, safety, and preliminary efficacy of a vacuum-based intra-colonic diverting device (Colovac) to reduce the impact of anastomotic leak. Methods. This prospective preclinical study was conducted on living swine. The device was surgically inserted transanally, proximal to a colorectal anastomosis, and removed endoscopically at day 14. Then, open surgery was performed to look for deep sepsis and/or anastomotic leak, and the remaining colorectal anastomosis was resected for histopathological analysis. The endpoints were successful insertion and delivery of the device, postoperative morbidity, successful maintaining of the device, and absence of feces spillage and/or abscess in the abdominal cavity. Results. The Colovac was inserted in 22 swine. Stent migration occurred in 7 of the first 8 specimens, leading to natural expulsion of the device. After diet adaptation, a subsequent group of 14 swine was undertaken, of which 13 did not show any sign of migration post-implantation. Disconnection of the suction drain occurred in 1 case, leading to device expulsion on day 10. Colovac retrieval was achieved successfully in 13 cases. The endoscopic assessment of the anchorage site showed limited mucosal injury, whereas histopathological findings revealed mild hyperplasia. One swine died prematurely of postoperative colonic ischemia. Conclusion. This new device appears to be safe in the swine model and may prevent peritonitis or abscess due to colorectal anastomotic leak.

Laser speckle contrast imaging and quantitative fluorescence angiography for perfusion assessment

PURPOSE

Indocyanine green fluorescence angiography (ICG-FA) is an established technique for assessment of intestinal perfusion during gastrointestinal surgery, whereas quantitative ICG-FA (q-ICG) and laser speckle contrast imaging (LSCI) are relatively unproven. The study aimed to investigate whether the techniques could be applied interchangeably for perfusion assessment.

METHODS

Nineteen pigs underwent laparotomy, two minor resections of the small bowel, and anastomoses. Additionally, seven pigs had parts of their stomach and small intestine de-vascularized. Data was also collected from an in vivo model (inferior caval vein measurements in two additional pigs) and an ex vivo flow model, allowing for standardization of experimental flow, distance, and angulation. Q-ICG and LSCI were performed, so that regions of interest were matched between the two modalities in the analyses, ensuring coverage of the same tissue.

RESULTS

The overall correlation of q-ICG and LSCI evaluated in the porcine model was modest (rho = 0.45, p < 0.001), but high in tissue with low perfusion (rho = 0.74, p < 0.001). Flux values obtained by LSCI from the ex vivo flow model revealed a decreasing flux with linearly increasing distance as well as angulation to the model. The Q-ICG perfusion values obtained varied slightly with increasing distance as well as angulation to the model.

CONCLUSIONS

Q-ICG and LSCI cannot be used interchangeably but may supplement each other. LSCI is profoundly affected by angulation and distance. In comparison, q-ICG is minimally affected by changing experimental conditions and is more readily applicable in minimally invasive surgery.

Quantitative perfusion assessment of intestinal anastomoses in pigs treated with glucagon-like peptide 2

PURPOSE

Despite exhaustive research and improvement of techniques, anastomotic leakage remains a frequent complication in gastrointestinal surgery. As leakage is associated with poor perfusion, reliable objective methods to assess anastomotic perfusion are highly demanded. In addition, such methods enable evaluation of interventions that may improve anastomotic perfusion. Glucagon-like peptide 2 (GLP-2) is an enteroendocrine hormone that regulates mid-gut perfusion. In the present study, we aimed to explore if quantitative perfusion assessment with indocyanine green (q-ICG) could detect an increase in porcine anastomotic perfusion after treatment with GLP-2.

METHODS

Nineteen pigs had two small bowel resections followed by anastomosis. Blinded to all investigators, animals were randomized to receive GLP-2 or placebo. Anastomotic perfusion was assessed at baseline, 30 min after injection of GLP-2/placebo, and after 5 days of treatment. Anastomotic strength and healing were evaluated by bursting pressure and histology.

RESULTS

Q-ICG detected a significantly higher increase in anastomotic perfusion (p < 0.05) in animals treated with GLP-2, compared with placebo. No significant differences in anastomotic strength or healing were found.

CONCLUSIONS

Q-ICG is a promising tool for perfusion assessment in gastrointestinal surgery and opens new opportunities in research of factors that may influence anastomotic healing, but further research is warranted to evaluate the effects of GLP-2 on anastomotic healing.

Effects of Ghrelin on the Oxidative Stress and Healing of the Colonic Anastomosis in Rats

BACKGROUND

Anastomotic leakage is the deadliest complication of colonic procedures. Ghrelin is an orexigenic hormone with potent actions on growth hormone release and functions in the processes of growth, tissue inflammation, repair, and oxidative stress. We evaluated the hypothesis that the exogenous administration of ghrelin causes beneficial effects on the healing of colonic anastomosis.

MATERIALS AND METHODS

Sixty-four male Wistar rats were randomly assigned to eight subgroups receiving postoperative intraperitoneal administration of ghrelin (23 μg/kg/d) or saline after a colonic anastomosis. The anastomotic tissue was evaluated on the third, seventh, and 14th postoperative days. Anastomotic bursting pressure, histological parameters, hydroxyproline content, and tissue oxidative stress markers were compared.

RESULTS

There was a significant increase in the mean anastomotic bursting pressure in the ghrelin subgroup on the seventh postoperative day (P = 0.035). Histological evaluation demonstrated a significant difference in the neutrophilic infiltrate (P = 0.035) on the third and 14th d and in apoptosis (P = 0.004), granulation tissue (P = 0.011) and peritoneal inflammation (P = 0.014) on the 14th postoperative day. There was a statistically significant increase in the hydroxyproline content in the ghrelin subgroup on the 14th postoperative day (P = 0.043). There were significant differences in the nitrite tissue levels (P = 0.021) on day 3 and in reactive oxygen species (P = 0.012) on day 14.

CONCLUSIONS

The administration of ghrelin had beneficial anti-inflammatory and antioxidant effects, increasing the resistance of the anastomosis and the hydroxyproline tissue content in the postoperative period.

Utilization of indocynanine green fluorescent imaging (ICG-FI) for the assessment of microperfusion in vascular medicine

Intraoperative valuation of organ and tissue microperfusion is always a current topic in different surgical situations. Although indocyanine green fluorescent imaging (ICG-FI) has turned to be a more and more common technique to evaluate organ perfusion, only few studies tried to quantitatively validate the technique for microperfusion assessment. The aim of the following manuscript is to present the results of our interdisciplinary research confirming additional quantitative assessment tools in different surgical conditions. Thus, we are implementing the background-subtracted peak fluorescent intensity (BSFI), the slope of fluorescence intensity (SFI), and the time to slope (TTS) using ICG-FI in several regions of interest (ROI).

Indocyanine green enhanced surgery; principle, clinical applications and future research directions

Over the past decade a new emergent technology has become very popular in all fields of surgery using Indocyanine green and near infrared fluorescent optical systems. This revolutionary approach overlaps conventional and near infrared images to produce highly informative intraoperative images on the anatomy and physiology of various tissues. Near infrared fluorescence is employed for perioperative angiography in vascular mapping, assessment of anastomoses, location of sentinel lymph nodes and delineation of biliary tree anatomy, highlighting tumours and metastatic deposits, improving surgical techniques and for many other uses. A lot of researchers have reported better surgical outcomes and technique innovations facilitated by this novel technology which although in its early stages, it lights up great interest worldwide. This article reviews the principle of the method, the properties of the fluorescent dye, the main clinical applications and discusses future research directions.

Risk Factors for Gastrointestinal Leak after Bariatric Surgery: MBASQIP Analysis

BACKGROUND

Gastrointestinal leak remains one of the most dreaded complications in bariatric surgery. We aimed to evaluate risk factors and the impact of common perioperative interventions on the development of leak in patients who underwent laparoscopic bariatric surgery.

STUDY DESIGN

Using the 2015 database of accredited centers, data were analyzed for patients who underwent laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass (LRYGB). Emergent, revisional, and converted cases were excluded. Multivariate logistic regression was used to analyze risk factors for leak, including provocative testing of anastomosis, surgical drain placement, and use of postoperative swallow study.

RESULTS

Data from 133,478 patients who underwent laparoscopic sleeve gastrectomy (n = 92,495 [69.3%]) and LRYGB (n = 40,983 [30.7%]) were analyzed. Overall leak rate was 0.7% (938 of 133,478). Factors associated with increased risk for leak were oxygen dependency (adjusted odds ratio [AOR] 1.97), hypoalbuminemia (AOR 1.66), sleep apnea (AOR 1.52), hypertension (AOR 1.36), and diabetes (AOR 1.18). Compared with LRYGB, laparoscopic sleeve gastrectomy was associated with a lower risk of leak (AOR 0.52; 95% CI 0.44 to 0.61; p < 0.01). Intraoperative provocative test was performed in 81.9% of cases and the leak rate was higher in patients with vs without a provocative test (0.8% vs 0.4%, respectively; p < 0.01). A surgical drain was placed in 24.5% of cases and the leak rate was higher in patients with vs without a surgical drain placed (1.6% vs 0.4%, respectively; p < 0.01). A swallow study was performed in 41% of cases and the leak rate was similar between patients with vs without swallow study (0.7% vs 0.7%; p = 0.50).

CONCLUSIONS

The overall rate of gastrointestinal leak in bariatric surgery is low. Certain preoperative factors, procedural type (LRYGB), and interventions (intraoperative provocative test and surgical drain placement) were associated with a higher risk for leaks.

Glucagon like peptide-2 and neoplasia; a systematic review

Glucagon like peptide-2 is synthesized from enteroendocrine L cells primarily located in the ileum and large intestine. GLP-2 stimulates crypt cell proliferation, increases intestinal blood flow, enhances gut barrier function, induces mucosal healing, and exerts an anti-apoptotic effect. Due to these effects GLP-2 is used in the treatment of short bowel syndrome (SBS). Areas covered: The aim of this systematic review was to provide information on the potential risk of intestinal neoplasia in patients receiving treatment with GLP-2. The literature search was performed independently by two authors in the following databases; Pubmed, Embase, Scopus, Web of Science and Cochrane. Expert commentary: This systematic review indicated that treatment with GLP-2(1-33) up to 30 months in humans without any known pre-existing cancer did not confer an increased risk of intestinal neoplasia in patients or animals. However, due to the small amount of patients studied it is premature to reach any final conclusions about GLP-2 - induced neoplasia. GLP-2(1-33) treatment in animals with a pre-induced cancer showed that GLP-2(1-33) may promote growth of existing neoplasia.

Roles of Macrophage Subtypes in Bowel Anastomotic Healing and Anastomotic Leakage

Macrophages play an important role in host defense, in addition to the powerful ability to phagocytose pathogens or foreign matters. They fulfill a variety of roles in immune regulation, wound healing, and tissue homeostasis preservation. Macrophages are characterized by high heterogeneity, which can polarize into at least two major extremes, M1-type macrophages (classical activation) which are normally derived from monocytes and M2-type macrophages (alternative activation) which are mostly those tissue-resident macrophages. Based on the wound healing process in skin, the previous studies have documented how these different subtypes of macrophages participate in tissue repair and remodeling, while the mechanism of macrophages in bowel anastomotic healing has not yet been established. This review summarizes the currently available evidence regarding the different roles of polarized macrophages in the physiological course of anastomotic healing and their pathological roles in anastomotic leakage, the most dangerous complication after gastrointestinal surgery.

Perioperative use of nonsteroidal anti-inflammatory drugs and the risk of anastomotic failure in emergency general surgery

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used analgesic and anti-inflammatory adjuncts. Nonsteroidal anti-inflammatory drug administration may potentially increase the risk of postoperative gastrointestinal anastomotic failure (AF). We aim to determine if perioperative NSAID utilization influences gastrointestinal AF in emergency general surgery (EGS) patients undergoing gastrointestinal resection and anastomosis.

METHODS

Post hoc analysis of a multi-institutional prospectively collected database was performed. Anastomotic failure was defined as the occurrence of a dehiscence/leak, fistula, or abscess. Patients using NSAIDs were compared with those without. Summary, univariate, and multivariable analyses were performed.

RESULTS

Five hundred thirty-three patients met inclusion criteria with a mean (±SD) age of 60 ± 17.5 years, 53% men. Forty-six percent (n = 244) of the patients were using perioperative NSAIDs. Gastrointestinal AF rate between NSAID and no NSAID was 13.9% versus 10.7% (p = 0.26). No differences existed between groups with respect to perioperative steroid use (16.8% vs. 13.8%; p = 0.34) or mortality (7.39% vs. 6.92%, p = 0.84). Multivariable analysis demonstrated that perioperative corticosteroid (odds ratio, 2.28; 95% confidence interval, 1.04-4.81) use and the presence of a colocolonic or colorectal anastomoses were independently associated with AF. A subset analysis of the NSAIDs cohort demonstrated an increased AF rate in colocolonic or colorectal anastomosis compared with enteroenteric or enterocolonic anastomoses (30.0% vs. 13.0%; p = 0.03).

CONCLUSION

Perioperative NSAID utilization appears to be safe in EGS patients undergoing small-bowel resection and anastomosis. Nonsteroidal anti-inflammatory drug administration should be used cautiously in EGS patients with colon or rectal anastomoses. Future randomized trials should validate the effects of perioperative NSAIDs use on AF.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Intestinal inflammatory and redox responses to the perioperative administration of teduglutide in rats

Purpose:

To investigate the inflammatory and redox responses to teduglutide on an animal model of laparotomy and intestinal anastomosis.

Methods:

Wistar rats (n=62) were allocated into four groups: "Ileal Resection and Anastomosis" vs. "Laparotomy", each one split into "Postoperative Teduglutide Administration" vs. "No Treatment"; and euthanized at the third or the seventh day. Ileal and blood samples were recovered at the baseline and at the euthanasia. Flow cytometry was used to study the inflammatory response (IL-1α, MCP-1, TNF-α, IFN-γ and IL-4 levels), oxidative stress (cytosolic peroxides, mitochondrial reactive species, intracellular glutathione and mitochondrial membrane potential) and cellular viability and death (annexin V/propidium iodide double staining).

Results:

Postoperative teduglutide treatment was associated with higher cellular viability index and lower early apoptosis ratio at the seventh day; higher cytosolic peroxides level at the third day and mitochondrial overgeneration of reactive species at the seventh day; higher tissue concentration of IL-4 and lower local pro-to-anti-inflammatory cytokines ratio at the seventh day.

Conclusion:

Those findings suggest an intestinal pro-oxidative and anti-inflammatory influence of teduglutide on the peri-operative context with a potential interference in the intestinal anastomotic healing.

Sustained-released mixture of vascular endothelial growth factor 165 and fibrin glue strengthens healing of ileal anastomoses in a rabbit model with intraperitoneal infection

Purpose

To investigate the effects of a sustained-released mixture of vascular endothelial growth factor 165 (VEGF165) and fibrin glue (FG) local administration on postoperative rabbit ileal anastomoses.

Methods

One hundred twenty-eight male and female New Zealand white rabbits underwent intraperitoneal infection subsequent ileal anastomosis surgery were divided randomly into 4 groups, including 32 animals in each, applied with saline solution, FG, rhVEGF165 and a mixture of rhVEGF165 with FG (VEGF + FG) on the anastomoses, respectively. The incidences of anastomotic leakage were observed. Histopathological examination for inflammatory infiltration, fibroblast proliferation, and capillary vascular proliferation were performed. Then, bursting pressure and hydroxyproline concentrations were assessed in anastomoses sits on postoperative days 3, 5, 7, and 14.

Results

Rabbits in VEGF + FG group had the lowest incidence of leakage (P < 0.05). Histological evaluations revealed that granulation tissue was formed on days 5 after anastomosis; fibroblast proliferation and capillary vascular proliferation were significantly increased on days 7 and 14 in VEGF + FG group. Furthermore, there was a statistically significant difference in the mean bursting pressures between VEGF + FG group and other groups on days 7 and 14 (P < 0.05), and rabbits in VEGF + FG group exhibited a higher concentration than VEGF group (P < 0.05) and FG group (P < 0.05) on day 14.

Conclusion

Administration of VEGF165 mixed with FG to ileal anastomosis accelerates wound healing and enhances the anastomosis by increased angiogenesis.

Relation between postoperative ileus and anastomotic leakage after colorectal resection: a post hoc analysis of a prospective randomized controlled trial

AIM

Anastomotic leakage (AL) following abdominal surgery is a critical determinant of postoperative recovery, of which the aetiology is largely unknown. Interestingly, interventions aimed at reducing the inflammatory response and postoperative ileus (POI) have an unexpected effect on AL. The aim of this study was to investigate the relation of POI with inflammation and AL after colorectal resection.

METHOD

A post hoc analysis of a prospective randomized controlled trial in which patients underwent a colorectal resection was performed. Patients undergoing a colorectal resection were stratified into having or not having POI. The incidence of AL and other clinical parameters was registered prospectively. Intestinal fatty acid binding protein (I-FABP, a marker for tissue damage) and the inflammatory response in plasma and colon tissue were determined.

RESULTS

AL was present in nine of 43 patients in the POI group, and in one of 65 in the group without POI (P < 0.001). There was a significant association between POI and AL (OR 12.57, 95% CI: 2.73-120.65; P = 0.0005). Patients with POI had significantly higher plasma levels of soluble tumour necrosis factor receptor 1 (TNFRSF1A) at 4 h postoperatively (0.89 ng/l, interquartile range 0.56) than patients without POI (0.80 ng/l, interquartile range 0.37; P = 0.04) and higher plasma levels of C-reactive protein on the second day postoperatively (234 ± 77 vs 163 ± 86 mg/l; P = 0.001). Patients who developed AL had significantly higher plasma levels of I-FABP compared with patients without AL at 24 h after onset of surgery.

CONCLUSION

POI is associated with a higher prevalence of AL and an increased inflammatory response.

Nonsteroidal anti-inflammatory drugs and the risk of anastomotic leakage after anterior resection for rectal cancer

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely used in colorectal surgery due to their opioid-sparing effect. However, several studies have indicated an increased risk of anastomotic leakage following NSAID treatment, although conflicting results exist. The primary goal of this study was to further examine whether postoperative NSAIDs are independently associated with anastomotic leakage after anterior resection for rectal cancer.

METHODS

Patients who underwent anterior resection for rectal cancer during 2007-2013 in 15 different hospitals in three healthcare regions in Sweden were included in the study. Registry data and information from patient records were retrieved. The association between NSAID treatment (for at least two days in the first postoperative week) and symptomatic anastomotic leakage (within 90 days) was evaluated with multiple logistic regression, with adjustment for pertinent confounding factors.

RESULTS

Some 1495 patients were included in the study. Of these, 27% received postoperative NSAIDs for at least two days in the first postoperative week. Symptomatic anastomotic leakage occurred in 11% and 14% in the NSAID and non-NSAID group, respectively. With adjustment for confounders, the odds ratio for leakage among patients who received NSAIDs compared with those who did not was 0.88 (95% CI 0.65-1.20). No differences were seen between non-selective and COX-2-selective NSAIDs.

CONCLUSION

Postoperative NSAID treatment does not seem to increase the risk of symptomatic anastomotic leakage after anterior resection for rectal cancer. NSAID use appears to be safe, but a well-powered randomized clinical trial is warranted.

Perioperative blood transfusions increases the risk of anastomotic leakage after surgery for GEJ-cancer

OBJECTIVE

To investigate the effect of blood transfusions on the risk of anastomotic leakage (AL) in patients with gastro-esophageal-junction (GEJ) cancer.

BACKGROUND

The incidence of GEJ cancer is increasing in the western world. Surgery is the curative treatment of choice. AL increases mortality and morbidity, and increases the risk cancer reoccurrence. In colo-rectal surgery a relation between AL and blood transfusions have been demonstrated.

METHOD

The risk of AL in relation to blood transfusions was investigated in a cohort study. 253 consecutive patients undergoing surgery for GEJ cancer was included. Data was based on a prospective maintained database and analyzed using logistic regressions models adjusting for multiple confounders.

RESULTS

We found an increased risk of AL when blood was transfused OR: 3.47, (1.51; 7.99). This relation was consistent after adjustment for multiple confounders OR: 4.60, (1.29; 16.4). Increasing number of blood units did not increase risk of AL further.

CONCLUSION

We present data demonstrating a strong correlation between receiving blood transfusions and the risk of AL after surgery in GEJ cancers patients.

In vivo and in vitro assessment of the biocompatibility and degradation of high-purity Mg anastomotic staples

Titanium (Ti) staples are not biodegradable, and anastomotic complications related to Ti staples are reported frequently. In the present study, the biocompatibility and degradation behavior of high-purity magnesium (HP Mg) staples with the small intestine were investigated. HP Mg staples did not affect the relative growth rate, cell cycle and apoptosis of primary rectal mucosal epithelial cells (IEC-6) in vitro. At one, two and three days after immersion in intestinal juice, the weight of the 30 rinsed HP Mg staples reduced by 7.5 ± 1.6, 10.6 ± 2.2 and 13.5 ± 2.1 mg, respectively, and those in the Hanks' solution reduced by 3.9 ± 0.8, 6.1 ± 1.2 and 7.1 ± 2.4 mg. Extracts of HP Mg staples were bio-safe for IEC-6, and the corrosion rate of HP staples was faster in the small intestinal juice than in the Hanks' solution. In the in vivo experiments, the small intestine of the minipigs was anastomosed by HP Mg and Ti staples. HP Mg staples neither affected important bio-chemical parameters nor induced serious inflammation or necrosis in the anastomosis tissues. The residual weight of a HP Mg staples (0.81 ± 0.13 mg) was 89.7% of the original weight (9 ± 0.09 mg) one month after surgery. The in vivo corrosion rate for one HP Mg staple was determined to be∼0.007 ± 0.001 mm·month^-1. The preliminary results of the biocompatibility and degradation of high-purity Mg anastomotic staples are promising, and further studies will be initiated to study in more detail.

A systematic analysis of controlled clinical trials using the NiTi CAR™ compression ring in colorectal anastomoses

Anastomotic leak following colorectal surgery can be a devastating adverse event. The ideal stapling device should be capable of rapid creation of an anastomosis with serosal apposition without the persistence of a foreign body or a foreign body reaction which potentially contribute to early anastomotic dehiscence or late anastomotic stricture. A systematic review was performed examining available data on controlled randomized and non-randomized trials assessing the NiTi compression anastomosis ring-(NiTi CAR™) (NiTi Solutions, Netanyah Israel) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards. A protocol for this meta-analysis has been registered on PROSPERO (CRD42016050934). The initial search yielded 45 potentially relevant articles. After screening titles and abstracts for relevance and assessment for eligibility, 39 of these articles were eventually excluded leaving 6 studies for analysis in the review. Regarding the primary outcome measure, the overall anastomotic leak rate was 2.2% (5/230) in the compression anastomosis group compared with 3% (10/335) in the conventional anastomosis group; this difference was not statistically significant (RR 0.75, 95% CI 0.25-2.24; participants = 565; studies = 6; I ² = 0%). There were no statistically significant differences between compression and conventional anastomoses in any of the secondary outcomes. This review was unable to demonstrate any statistically significant differences in favor of the compression anastomosis technique over conventional manual or stapled mechanical anastomoses.

Quantification of fluorescence angiography in a porcine model

PURPOSE

There is no consensus on how to quantify indocyanine green (ICG) fluorescence angiography. The aim of the present study was to establish and gather validity evidence for a method of quantifying fluorescence angiography, to assess organ perfusion.

METHODS

Laparotomy was performed on seven pigs, with two regions of interest (ROIs) marked. ICG and neutron-activated microspheres were administered and the stomach was illuminated in the near-infrared range, parallel to continuous recording of fluorescence signal. Tissue samples from the ROIs were sent for quantification of microspheres to calculate the regional blood flow. A software system was developed to assess the fluorescent recordings quantitatively, and each quantitative parameter was compared with the regional blood flow. The parameter with the strongest correlation was then compared with results from an independently developed algorithm, to evaluate reproducibility.

RESULTS

A strong correlation was found between regional blood flow and the slope of the fluorescence curves (ROI I: Pearson r = 0.97, p < 0.001; ROI II: 0.96, p < 0.001) as the normalized slope (ROI I: Pearson r = 0.92, p = 0.004; ROI II: r = 0.96, p = 0.001). There was acceptable correlation of the slope of the curve between two independently developed algorithms (ROI I+II: Pearson r = 0.83, p < 0.001), and good resemblance was found with the Bland-Altman method, with no proportional bias.

CONCLUSIONS

Perfusion assessment with quantitative indocyanine green fluorescence angiography is not only feasible but easy to perform with commercially available equipment and readily accessible software.

Can Human Recombinant Epidermal Growth Factor Improve Ischemia and Induce Healing of Anastomosis in an Experimental Study in a Rabbit Model?

PURPOSE

Anastomotic leaks following intestinal operations may cause devastating effects on patients. Ischemia may also occur at the intestinal walls in the presence of strangulations. In this study, we examined the effects of human recombinant (Hr)-epidermal growth factor (EGF) given at a single intramural dose into the intestinal walls and daily intraperitoneal cavity on ischemia and the healing process of anastomosis.

MATERIALS AND METHODS

Sixteen male New Zeland white rabbits were randomly divided into four groups (n = 4 in each group). In Group 1, two different segments of ileum were identified and, then, transected and the free ends were sutured each other. In the other groups, ischemia was induced by ligating the mesenteric vascular arcade. After the ischemic induction, Group 2 received intramural injections of %0.9 saline, Group 3 received intramural injections of a single dose of EGF, and Group 4 received intramural and intraperitoneal injections of EGF. Bursting pressures and tissue hydroxyproline levels were analyzed. Necrosis, fibroblastic activity, collagen deposition and neovascularization were also studied.

RESULTS

The mean levels of bursting pressures in Group 4 (148.6 ± 25.3 mmHg) were higher than Group 2 (70 ± 21.5 mmHg) (p = 0.001). The mean level of bursting pressures was not statistically significant between Group 1 (170.1 ± 35 mmHg) and Group 4 (p = 0.073). Hydroxyproline levels in Group 2 were lower than Groups 3 and 4. There was a statistically significant difference in the mucosal ischemia, mucosal healing and degree of adhesion, but not in the mural anastomotic healing among the groups.

CONCLUSIONS

Intramural injection with daily intraperitoneal administration of low-dose EGF enhances the bursting pressure and collagen accumulation in ischemic anastomosis, improving many histological variables associated with ischemic intestinal anastomosis.

Prevention of Perioperative Anastomotic Healing Complications: Anastomotic Stricture and Anastomotic Leak

The anastomotic healing complications of postoperative leak and stricture continue to plague surgeons despite many broadly targeted interventions. Evaluation of preventive measure efficacy is difficult due to inconsistent definitions and reporting of these complications. Few interventions have been shown to impact rates of leakage or stricture. However, new evidence is emerging that the intestinal microbiota can play an important role in the development of anastomotic complications. A more holistic approach to understanding the mechanisms of anastomotic complications is needed in order to develop tailored interventions to reduce their frequency. Such an approach may require a more complete definition of the role of the microbiota in anastomotic healing.

Compression versus hand-sewn and stapled anastomosis in colorectal surgery: a systematic review and meta-analysis of randomized controlled trials

Anastomotic leaks are a feared complication of colorectal resections and novel techniques that have the potential to decrease them are still sought. This study aimed to compare the anastomotic leak rates in patients undergoing compression anastomoses versus hand-sewn or stapled anastomoses. Randomized controlled trials (RCTs) comparing outcomes of compression versus conventional (hand-sewn and stapled) colorectal anastomosis were collected from MEDLINE, Embase and the Cochrane Library. The quality of the RCTs and the potential risk of bias were assessed. Pooled odds ratios (OR) were calculated for categorical outcomes and weighted mean differences for continuous data. Ten RCTs were included, comprising 1969 patients (752 sutured, 225 stapled, and 992 compression anastomoses). Most used the biofragmentable anastomotic ring. There was no significant difference between the two groups in terms of anastomotic leak rates (OR 0.80, 95 % confidence interval (CI) 0.47, 1.37; p = 0.42), stricture (OR 0.54: 95 % CI 0.18, 1.64; p = 0.28) or mortality (OR 0.70; 95 % CI 0.39, 1.26; p = 0.24). Compression anastomosis was associated with an earlier return of bowel function: 1.02 (95 % CI 1.37, 0.66) days earlier (p < 0.001) and a shorter postoperative stay; 1.13 (95 % CI 1.52, 0.74) days shorter (p < 0.001), but significant heterogeneity among studies was observed. There was an increased risk of postoperative bowel obstruction in the compression group (OR 1.87; 95 % CI 1.07, 3.26; p = 0.03). There was no significant difference in wound-related and general complications, or length of surgery. Compression devices do not appear to provide an advantage over conventional techniques in fashioning colorectal anastomoses and are associated with an increased risk of bowel obstruction.

Significant elevation of carcinoembryonic antigen levels in abdominal drains after colorectal surgery may indicate early anastomotic dehiscence

BACKGROUND

Anastomotic leak after colorectal surgery is a severe complication leading to major postoperative morbidity and mortality. Leaks typically present on the 5th to 6th postoperative days; however, early anastomotic dehiscence occurs occasionally. This study evaluated carcinoembryonic antigen (CEA) levels in abdominal drains after colorectal resection to assess its potential as an early marker to predict anastomotic leaks.

METHODS

This prospective study included 105 patients undergoing elective colorectal surgery. Fluids from the patients' abdominal drain system were sampled daily for up to 3 days after surgery and evaluated for CEA levels.

RESULTS

Early anastomotic dehiscence occurred in 3 patients (2.8%) and was associated with a significant elevation of CEA in drain fluids (above 1,000 ng/mL). However, in patients who developed late leaks (7 patients, 6.7%) no significant elevation of CEA was observed.

CONCLUSIONS

Significant elevation of CEA levels in abdominal drains in the early postoperative period may indicate early anastomotic dehiscence.

Management of Severe Sepsis of Abdominal Origin

Severe sepsis is a life-threatening condition that may occur as a sequela of intra-abdominal infections (IAIs) of all types. Diagnosis of IAIs is predicated upon the combination of physical examination and imaging techniques. Diffuse peritonitis usually requires urgent surgical intervention. In the absence of diffuse peritonitis, abdominal computed tomography remains the most useful test for the diagnosis of IAIs, and is essential to both guide therapeutic interventions and evaluate suspected treatment failure in the critically ill patient. Parameters most consistently associated with poor outcomes in patients with IAIs include increased illness severity, failed source control, inadequate empiric antimicrobial therapy, and healthcare-acquired, as opposed to community-acquired infection. Whereas community-acquired IAI is characterized predominantly by enteric gram-negative bacilli and anaerobes that are susceptible to narrow-spectrum agents, healthcare-acquired IAI (e.g., anastomotic dehiscence, postoperative organ-space surgical site infection) frequently involves at least one multi-drug resistant pathogen, necessitating broad-spectrum therapy guided by both culture results and local antibiograms. The cornerstone of effective treatment for abdominal sepsis is early and adequate source control, which is supplemented by antibiotic therapy, restoration of a functional gastrointestinal tract (if possible), and support of organ dysfunction. Furthermore, mitigation of deranged immune and coagulation responses via therapy with recombinant human activated protein C may improve survival significantly in severe cases complicated by septic shock and multiple organ dysfunction syndrome.