Healing in the gastrointestinal tract

The effect of preoperative mechanical bowel preparation in paediatric bowel surgery on postoperative wound related complications: A meta-analysis

Mechanical bowel preparation (MBP), a routine nursing procedure before paediatric bowel surgery, is widely should in clinical practice, but its necessity remains controversial. In a systematic review and meta-analysis, we evaluated the effect of preoperative MBP in paediatric bowel surgery on postoperative wound-related complications in order to analyse the clinical application value of MBP in paediatric bowel surgery. As of November 2023, we searched four online databases: the Cochrane Library, Embase, PubMed, and Web of Science. Two investigators screened the collected studies against inclusion and exclusion criteria, and ROBINS-I was used to evaluate the quality of studies. Using RevMan5.3, a meta-analysis of the collected data was performed, and a fixed-effect model or a random-effect model was used to analyse OR, 95% CI, SMD, and MD. A total of 11 studies with 2556 patients were included. Most of studies had moderate-to-severe quality bias. The results of meta-analysis showed no statistically significant difference in the incidence of complications related to postoperative infections in children with MBP before bowel surgery versus those with No MBP, wound infection (OR 1.11, 95% CI:0.76 ~ 1.61, p = 0.59, I2 = 5%), intra-abdominal infection (OR 1.26, 95% CI:0.58 ~ 2.77, p = 0.56, I2 = 9%). There was no significant difference in the risk of postoperative bowel anastomotic leak (OR 1.07, 95% CI:0.68 ~ 1.68, p = 0.78, I2 = 12%), and anastomotic dehiscence (OR 1.67, 95% CI:0.13 ~ 22.20, p = 0.70, I2 = 73%). Patients' intestinal obstruction did not show an advantage of undergoing MBP preoperatively, with an incidence of intestinal obstruction (OR 1.95, 95% CI:0.55 ~ 6.93, p = 0.30, I2 = 0%). Based on existing evidence that preoperative MBP in paediatric bowel surgery did not reduce the risk of postoperative wound complications, we cautiously assume that MBP before surgery is unnecessary for children undergoing elective bowel surgery. However, due to the limited number of study participants selected for this study and the overall low quality of evidence, the results need to be interpreted with caution. It is suggested that more high quality, large-sample, multicenter clinical trials are required to validate our findings.

A predictive model for intraabdominal infection after radical gastrectomy in elderly patients

Gastric cancer (GC) is one of the most common malignant tumors worldwide and the fourth leading cause of cancer-related deaths, with a relatively high incidence among the elderly population. Surgical resection is the mainstay treatment for GC and is currently the only cure. However, the incidence of postoperative intraabdominal infections remains high and seriously affects the prognosis. This study aimed to explore the risk factors for intraabdominal infections after radical gastrectomy in elderly patients and to establish and validate a risk prediction model. We collected the clinical data of 322 GC patients, who underwent radical gastrectomy at the General Surgery Department of China Medical University Dandong Central Hospital from January 2016 to January 2023. The patients were divided into an infected group (n = 27) and a noninfected group (n = 295) according to whether intraabdominal infections occurred postoperatively. A nomogram risk prediction model for the occurrence of postoperative intraabdominal infections was developed. All patients were randomized into a training set (n = 225) and a validation set (n = 97) in a 7:3 ratio, and the model was internally validated. Of the 322 patients, 27 (8.3%) experienced postoperative intraabdominal infections. Single-factor analysis revealed associations of intraabdominal infection with body mass index, glucose, hemoglobin, albumin, and other factors. The multifactorial analysis confirmed that body mass index, glucose, hemoglobin, albumin, surgical duration, and bleeding volume were independent risk factors for intraabdominal infections. The nomogram constructed based on these factors demonstrated excellent performance in both the training and validation sets. A nomogram model was developed and validated to predict the risk of intraabdominal infection after radical gastrectomy. The model has a good predictive performance, which could help clinicians prevent the occurrence of intraabdominal infections after radical gastrectomy in elderly patients.

Personalized Treatments Based on Laryngopharyngeal Reflux Patient Profiles: A Narrative Review

OBJECTIVE

To review the current findings of the literature on the existence of several profiles of laryngopharyngeal reflux (LPR) patients and to propose personalized diagnostic and therapeutic approaches.

METHODS

A state-of-the art review of the literature was conducted using the PubMED, Scopus, and Cochrane Library databases. The information related to epidemiology, demographics, clinical presentations, diagnostic approaches, and therapeutic responses were extracted to identify outcomes that may influence the clinical and therapeutic courses of LPR.

RESULTS

The clinical presentation and therapeutic courses of LPR may be influenced by gender, age, weight, comorbidities, dietary habits and culture, anxiety, stress, and saliva enzyme profile. The clinical expression of reflux, including laryngopharyngeal, respiratory, nasal, and eye symptoms, and the hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring profile of patients are important issues to improve in patient management. The use of more personalized therapeutic strategies appears to be associated with better symptom relief and cures over the long-term. The role of pepsin in LPR physiology is well-established but the lack of information about the role of other gastrointestinal enzymes in the development of LPR-related mucosa inflammation limits the development of future enzyme-based personalized diagnostic and therapeutic approaches.

CONCLUSION

Laryngopharyngeal reflux is a challenging ear, nose, and throat condition associated with poor therapeutic responses and a long-term burden in Western countries. Artificial intelligence should be used for developing personalized therapeutic strategies based on patient features.

Histological mapping of healing of the small and large intestine – a quantitative study in a porcine model

BACKGROUND

Gastrointestinal anastomoses are performed in many patients every year. The pathogenesis of aberrant anastomotic healing and the causes of intestinal leakage are not fully understood. The present study gathered and critically evaluated histological quantitative data to deepen current knowledge of anastomotic healing in the small and large intestine and its complications and outline the options for further experimental in vivo research in large porcine animal models.

METHODS

Three groups of porcine intestinal anastomoses were compared: small intestine without defect (SI; n=7), small intestine with an additional defect (SID; n=8), and large intestine (LI; n=7). Multilevel sampling (2,112 micrographs) and stereological methods were used for histological quantification of proliferation (Ki-67 immunohistochemistry), neutrophil infiltration (myeloperoxidase staining), vascularity (von Willebrand factor) and type I and type III collagen formation (picrosirius red in polarized light) within the region of anastomosis compared to the region outside of anastomosis.

RESULTS

Quantitative histological evaluation revealed the following results. i) Proliferation, vascularity, and collagen, but not neutrophils, were more highly expressed within the anastomosis than outside of the anastomosis region. ii) Porcine large and small intestine were not interchangeable based on histological evaluation of surgical experiments. The presence or absence of an additional experimental defect strongly affected healing, but the healing seemed complete after 21 days. iii) The microscopic structure of small intestine segments was more affected by their proximity to the anastomosis than the structure of large intestine segments.

CONCLUSIONS

Histological quantification was more laborious than the previously used semiquantitative scoring system evaluating the healing rate of intestinal anastomoses, but it provided detailed maps of biological processes within individual intestine layers. The primary data collected in the study are open and available for power sample analyses to calculate the minimum numbers of samples justified in future experiments on porcine intestines. The porcine intestine is a promising animal model with translational potential for human surgery.

Advances in Hydrogel Adhesives for Gastrointestinal Wound Closure and Repair

Millions of individuals undergo gastrointestinal (GI) tract surgeries each year with common postoperative complications including bleeding, perforation, anastomotic leakage, and infection. Today, techniques such as suturing and stapling seal internal wounds, and electrocoagulation stops bleeding. These methods induce secondary damage to the tissue and can be technically difficult to perform depending on the wound site location. To overcome these challenges and to further advance wound closure, hydrogel adhesives are being investigated to specifically target GI tract wounds because of their atraumatic nature, fluid-tight sealing capability, favorable wound healing properties, and facile application. However, challenges remain that limit their use, such as weak underwater adhesive strength, slow gelation, and/or acidic degradation. In this review, we summarize recent advances in hydrogel adhesives to treat various GI tract wounds, with a focus on novel material designs and compositions to combat the environment-specific challenges of GI injury. We conclude with a discussion of potential opportunities from both research and clinical perspectives.

The Esophagogastric Anastomosis: The Importance of Anchoring Sutures in Reducing Anastomotic Leak Rates

Background

The incidence of anastomotic leakage in gastrointestinal surgery is highest after esophagogastric anastomosis, with leakage rates of 10% to 38% still being reported, but little consensus as to cause or corrective. The role of anastomotic tension from a series of physiological forces acting on the anastomosis from the moment of recovery from anesthesia may be underestimated. It was hypothesized that anchoring the conduit in the mediastinum would provide the greatest protection during the vulnerable healing phase.

Patients and Methods

A prospectively maintained database was interrogated for anastomotic leakage following the introduction of an anastomotic technique employing anchoring sutures where the gastric conduit was secured to the mediastinal pleura with 3 obliquely inserted load-bearing sutures. A contrast study was performed between days 5 and 7 and all intrahospital mortalities underwent autopsy. Clinical, radiological, and autopsy leaks were recorded.

Results

Of 146 intrathoracic esophagogastric anastomoses in 144 patients, 81 (55%) of which were stapled, there was 1 clinical leak and 1 patient with an aortoenteric fistula, considered at autopsy to be possibly due to an anastomotic leak, to give an anastomotic leak rate of 2 in 146 (1.37%).

Conclusion

The low anastomotic leak rate in this series is potentially due to the protective effect of anchoring sutures, the chief difference from an otherwise standard anastomotic technique. These sutures protect the anastomosis from a series of distracting forces during the most vulnerable phase of healing. It is intuitive that the absence of tension would also reduce any risk posed by a minor impairment of blood supply or any imperfection of the technique.

Wettability and biological responses of titanium surface's biomimetic hexagonal microstructure

In this research, an experiment was conducted on how the surface wettability and biocompatibility of staplers' titanium nails impact the healing of gastrointestinal tissue. Firstly, the bionic hexagonal structure was prepared on the surface of Ti metal by laser processing technology, and the laser textured titanium samples were observed by scanning electron microscope. Then, the liquid-solid contact angle-measuring instrument was used to characterize the wettability of titanium samples. Finally, cells were cultured on the surface of different titanium samples, CCK8 assay and qRT-PCR were carried out to investigate cell adhesion and collagen secretion on the surface of different samples. The results showed that the bionic hexagonal surface increased the surface roughness, reduced the liquid-solid contact angle, and promoted the adhesion and collagen secretion of fibroblasts. The increased wettability provided a better growth environment for cell growth. Microtexture is an important factor affecting the behavior of cells and its size parameters regulate cell gene expression, which is worthy of further study.

Gaining Mesenteric Length following Colorectal Resection: Essential Maneuvers to Avoid Anastomotic Tension

A surgeon must possess the knowledge and technical skill to obtain length following a left-sided colorectal resection to perform a tension free anastomosis. The distal target organ - either rectum or anus - is fixed in location, and therefore requires surgeons to acquire mastery of proximal mobilization of the colonic conduit. Generally, splenic flexure mobilization (SFM) provides adequate length. Surgeons benefit from clearer understanding of the multiple steps involved in SFM as a result of improved visualization and demonstration of the relevant anatomy - adjacent organs and the attachments, embryologic planes, and mesenteric structures. Much may be attributed to laparoscopic and robotic platforms which provided improved exposure and as a result, development or refinement of novel approaches for SFM with potential advantages. Complete mobilization draws upon the sum or combination of the varied approaches to accomplish the goal. However, in the situation where extended resection is necessary or in the case of re-operative surgery sacrificing either more proximal or distal large intestine often occurs, the transverse colon or even the ascending colon represents the proximal conduit for anastomosis. This challenging situation requires familiarity with special maneuvers to achieve colorectal or coloanal anastomosis using these more proximal conduits. In such instances, operative techniques such as either ileal mesenteric window with retroileal anastomosis or de-rotation of the right colon (Deloyer's procedure) enable the intestinal surgeon to construct such anastomoses and thereby avoid stoma creation or loss of additional large intestine.

Distinct fibroblast progenitor subpopulation expedites regenerative mucosal healing by immunomodulation

Injuries that heal by fibrosis can compromise organ function and increase patient morbidity. The oral mucosal barrier has a high regenerative capacity with minimal scarring, but the cellular mechanisms remain elusive. Here, we identify distinct postnatal paired-related homeobox-1+ (Prx1+) cells as a critical fibroblast subpopulation that expedites mucosal healing by facilitating early immune response. Using transplantation and genetic ablation model in mice, we show that oral mucosa enriched with Prx1+ cells heals faster than those that lack Prx1+ cells. Lineage tracing and scRNA-seq reveal that Prx1+ fibroblasts exhibit progenitor signatures in physiologic and injured conditions. Mechanistically, Prx1+ progenitors accelerate wound healing by differentiating into immunomodulatory SCA1+ fibroblasts, which prime macrophage recruitment through CCL2 as a key part of pro-wound healing response. Furthermore, human Prx1+ fibroblasts share similar gene and spatial profiles compared to their murine counterpart. Thus, our data suggest that Prx1+ fibroblasts may provide a valuable source in regenerative procedures for the treatment of corneal wounds and enteropathic fibrosis.

Fusobacterium nucleatum induces colon anastomosis leak by activating epithelial cells to express MMP9

Background

Despite advances in anastomotic techniques and perioperative care, the incidence of anastomotic leak (AL) has not substantially decreased over time. Although it is known that AL etiology is multifactorial and the mechanisms involved remain unclear, there is accumulating evidence pointing at AL related to gut microbiota.

Method

We firstly performed a clinical study to analyze the gut microbiota between colorectal cancer patients who developed AL and those who did not (nAL) using 16S-rRNA sequencing and quantitative real-time PCR to identify AL risk bacterial taxa. Then we built a rat anastomosis model and performed a bacteria transplantation to ensure the cause-effect relationship. The anastomotic healing score was used to evaluate the healing of anastomosis. In addition, we assessed the adhesion ability of bacteria by staining with fluorescein isothiocyanate and attachment assay. The expression of matrix metalloproteinase 9 (MMP9) was detected by western blot, and the activity was detected by gelatin zymography.

Results

We found that the abundance and positive rate of Fusobacterium nucleatum (Fn) were higher in the AL patients. Exposure of the rat's colon anastomosis to Fn contributes to the loss of submucosa collagen I and III, leading to AL's pathogenesis. Fn can attach to the gut epithelial cells and stimulate intestinal MMP9 expression in vitro and in vivo. We further confirmed that these effects of Fn depended on the E-cadherin/β-catenin signaling pathway.

Conclusion

This work demonstrates that Fn attaches and then stimulates the expression of epithelial cells MMP9 by the E-cadherin/β-catenin signaling pathway. These effects contribute to collagen break down in the intestinal tissue, finally leading to AL.

New understanding of gut microbiota and colorectal anastomosis leak: A collaborative review of the current concepts

Anastomotic leak (AL) is a life-threatening postoperative complication following colorectal surgery, which has not decreased over time. Until now, no specific risk factors or surgical technique could be targeted to improve anastomotic healing. In the past decade, gut microbiota dysbiosis has been recognized to contribute to AL, but the exact effects are still vague. In this context, interpretation of the mechanisms underlying how the gut microbiota contributes to AL is significant for improving patients' outcomes. This review concentrates on novel findings to explain how the gut microbiota of patients with AL are altered, how the AL-specific pathogen colonizes and is enriched on the anastomosis site, and how these pathogens conduct their tissue breakdown effects. We build up a framework between the gut microbiota and AL on three levels. Firstly, factors that shape the gut microbiota profiles in patients who developed AL after colorectal surgery include preoperative intervention and surgical factors. Secondly, AL-specific pathogenic or collagenase bacteria adhere to the intestinal mucosa and defend against host clearance, including the interaction between bacterial adhesion and host extracellular matrix (ECM), the biofilm formation, and the weakened host commercial bacterial resistance. Thirdly, we interpret the potential mechanisms of pathogen-induced poor anastomotic healing.

An innovative and convenient technique to reduce anastomotic leakage after double stapling anastomosis: laparoscopic demucositized suture the overlapping point of the "dog ear" area

Anastomotic leakage (AL) is a major cause of postoperative morbidity and mortality in the treatment of colorectal cancer. The aim of this study was to investigate an innovative and convenient technique of laparoscopic demucositized suture the overlapping point of the "dog ear" area after the double stapling anastomosis (lds-DSA), as an improved alternative for conventional DSA, and whether it could reduce the AL rate in laparoscopic anterior resection (Lapa-AR). Between January 2018 and December 2020, a total of 245 patients who underwent Lapa-AR for the treatment of adenocarcinoma of the sigmoid colon or rectal cancer were divided into the lsd-DSA group (n = 99) and the DSA group (n = 146). Data were analyzed retrospectively. Morbidity, AL rate and other perioperative outcomes were compared between the two groups. Patient demographics, preoperative comorbidity, preoperative chemoradiotherapy, tumor size, stage, and other operative details were comparable between the two groups. There was no difference in surgical time between the two groups (196.41 ± 76.71 vs. 182.39 ± 49.10 min, p = 0.088). The overall complication rate was also without a difference (11/99, 11.11% vs. 21/146, 14.38%, p = 0.456), but AL rate significantly lower in the lsd-DSA group than in the DSA group (2/99, 2.02% vs. 12/146, 8.22%, p = 0.040). For other perioperative outcomes, the lsd-DSA group shortened the total and postoperative hospital stay, and the time to pull out drainage tube than in the DSA group. Our comparative study demonstrates lds-DSA to have a better short-term outcome in reducing AL compared with DSA. This technique could be an alternative approach to maximize the patients' benefit in Lapa-AR.

Intestinal Anastomotic Healing: What do We Know About Processes Behind Anastomotic Complications

Colorectal surgery has developed rapidly in the recent decades. Nevertheless, colorectal anastomotic leakage continues to appear postoperatively in unpleasant rates and leads to life-threatening conditions. The development of valid complication-preventing methods is inefficient in many aspects as we are still lacking knowledge about the basics of the process of anastomotic wound healing in the gastrointestinal tract. Without the proper understanding of the crucial mechanisms, research for prevention of anastomotic leakage is predestined to be unsuccessful. This review article discusses known pathophysiological mechanisms together with the most lately found processes to be further studied. The aim of the article is to facilitate the orientation in the topic, support the better understanding of known mechanisms and suggest promising possibilities and directions for further research.

Coating of Intestinal Anastomoses for Prevention of Postoperative Leakage: A Systematic Review and Meta-Analysis

Background

For several decades, scientific efforts have been taken to develop strategies and medical aids for the reduction of anastomotic complications after intestinal surgery. Still, anastomotic leakage (AL) represents a frequently occurring postoperative complication with serious consequences on health, quality of life, and economic aspects. Approaches using collagen and/or fibrin-based sealants to cover intestinal anastomoses have shown promising effects toward leak reduction; however, they have not reached routine use yet. To assess the effects of covering intestinal anastomoses with collagen and/or fibrin-based sealants on postoperative leakage, a systematic review and meta-analysis were conducted.

Method

PubMed, Web of Science, Cochrane Library, and Scopus (01/01/1964 to 17/01/2022) were searched to identify studies investigating the effects of coating any intestinal anastomoses with collagen and/or fibrin-based sealants on postoperative AL, reoperation rates, Clavien-Dindo major complication, mortality, and hospitalization length. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

Results

Overall, 15 studies (five randomized controlled trials, three nonrandomized intervention studies, six observational cohort studies) examining 1,387 patients in the intervention group and 2,243 in the control group were included. Using fixed-effects meta-analysis (I 2 < 50%), patients with coated intestinal anastomoses presented significantly lower AL rates (OR = 0.37; 95% CI 0.27-0.52; p < 0.00001), reoperation rates (OR, 0.21; 95% CI, 0.10-0.47; p = 0.0001), and Clavien-Dindo major complication rates (OR, 0.54; 95% CI, 0.35-0.84; p = 0.006) in comparison to controls, with results remaining stable in sensitivity and subgroup analyses (stratified by study design, age group, intervention used, location of anastomoses, and indication for surgery). The length of hospitalization was significantly shorter in the intervention group (weighted mean difference (WMD), -1.96; 95% CI, -3.21, -0.71; p = 0.002) using random-effects meta-analysis (I 2 ≥ 50%), especially for patients with surgery of upper gastrointestinal malignancy (WMD, -4.94; 95% CI, -7.98, -1.90; p = 0.001).

Conclusion

The application of collagen-based laminar biomaterials or fibrin sealants on intestinal anastomoses can significantly reduce postoperative rates of AL and its sequelae. Coating of intestinal anastomoses could be a step toward effective and sustainable leak prevention. To assess the validity and robustness of these findings, further clinical studies need to be conducted.

Association of ileocolic pedicle division with postoperative complications after restorative proctocolectomy and ileal pouch-anal anastomosis for ulcerative colitis

Background

When performing a restorative proctocolectomy (RPC) with an ileal pouch-anal anastomosis (IPAA), it is common practice to divide the ileocolic artery (ICA) if the patient has a tumor or dysplasia, or in order to gain sufficient length to secure a tension-free anastomosis. However, it is unclear whether there is an association between division of the ICA and the rate of postoperative complications.

Methods

We retrospectively analysed all patients with ulcerative colitis who underwent RPC and IPAA in our department between January 2010 and December 2016. These were divided in two groups, with regard to the ICA being preserved (PRE group) or divided (DIV group). Complications such as stenosis or leakage of the IPAA, perianal fistulas, abscess formation within the lesser pelvis and pouchitis were analysed and compared between both groups.

Results

We identified 130 patients meeting the study inclusion criteria, 49 patients in the PRE and 81 patients in the DIV group. No statistical significance was observed in IPAA leakages (p = 0.71), anastomotic strictures (p = 0.33), fistulas (p = 0.19) and pouchitis (p = 0.72). Abscess formation frequency was similar in both groups (p > 0.99). Moreover, short-term (p = 0.53) and long-term complications (p = 0.11) were similar in both groups. A higher conversion rate was observed in obese (p = 0.006) and male (p = 0.02) patients. Within the entire study population, fistulas and IPAA leakages were associated with a higher rate of anastomotic strictures (p = 0.008 and p = 0.02 respectively).

Conclusion

Our data suggest similar IPAA related complications after either division or preservation of the ICA. Further trials are required in order to examine the trends observed in this study.

The use of mesenchymal stem cells in animal models for gastrointestinal anastomotic leak: A systematic review

AIM

Anastomotic leak is the most feared complication of gastrointestinal surgery. Mesenchymal stem cell technology is used clinically to promote wound healing; however, the safety and efficacy of this technology on anastomotic healing has yet to be defined. The aim of this study was to investigate whether mesenchymal stem cells confer any benefit when applied to animal models for gastrointestinal anastomotic leak, identify the methodology and how efficacy is assessed.

METHODS

The MEDLINE, EMBASE, WebofScience and Cochrane Library databases were interrogated between 1 January1947 to 1 May 2020. All studies where mesenchymal stem cells were applied to laboratory animal leak models to demonstrate a healing effect were considered. All experimental and histological outcomes were examined. Compliance to ARRIVE and current International Consensus was assessed.

RESULTS

A total of 1205 studies were screened. Twelve studies reported on 438 gastrointestinal anastomoses in four species using 11 models; seven in the colon. No studies utilised a model with a known leak rate. Significant variance was observed in histological outcomes with efficacy demonstrated in five out of 12 studies. One study demonstrated a benefit in leak rate. Colorectal studies had a greater median ARRIVE compliance, 60.8% (IQR 63.2-64.5) compared to noncolorectal 45.4% (IQR 43.8-49.0).

CONCLUSIONS

Mesenchymal stem cell delivery to an animal anastomosis is safe and feasible. Use may confer benefit but findings are currently limited to surrogate histological outcomes. There is consistency in outcome measures reported but variance in how this is assessed. Poor compliance to ARRIVE but good compliance to current international consensus in leak models of the colon was observed.

Recanalization in Uncut Roux-en-Y Reconstruction: An Animal Experiment and a Clinical Study

Background: Because of the challenge of jejunal closure recanalization, uncut Roux-en-Y reconstruction remains controversial. This study aimed to investigate the incidence of recanalization after uncut Roux-en-Y reconstruction in pigs and a small number of patients.

Methods: Twenty miniature pigs were subjected to distal gastrectomy and uncut Roux-en-Y reconstruction using various rows of linear staplers to block the intestine. The pigs were sacrificed, and the incidence of recanalization was investigated 1 month after the operation. From December 2018 to June 2019, 10 patients with gastric cancer who had undergone elective laparoscopy-assisted distal gastrectomy and uncut Roux-en-Y reconstruction were included in this study. The primary study outcome was recanalization of the afferent limb, demonstrated by gastrointestinal radiography 1, 3, and 6 months after surgery. Various numbers of staple lines across the afferent jejunal limb were applied for closure: 2 staple lines in 2 pigs, 4 staple lines in 6 pigs, 6 staple lines in 8 pigs, and 8 staple lines in 4 pigs.

Results: Complete recanalization was detected in all 20 pigs 1 month postoperatively. Recanalization was detected in five cases (50%) by gastrointestinal radiography. Among them, 1 case of recanalization was found in the 1st month after the operation, 2 cases were found in the 3rd month, and another 2 cases were found in the 6th month. Bile reflux was detected by endoscopy in 2 patients with recanalization.

Conclusions: The occurrence of afferent limb recanalization after uncut Roux-en-Y reconstruction is high, and using additional staplers alone cannot decrease the incidence of recanalization. Based on our study, uncut Roux-en-Y reconstruction is not recommended.

Colorectal anastomotic leak: transcriptomic profile analysis

BACKGROUND

Anastomotic leakage in patients undergoing colorectal surgery is associated with morbidity and mortality. Although multiple risk factors have been identified, the underlying mechanisms are mainly unknown. The aim of this study was to perform a transcriptome analysis of genes underlying the development of anastomotic leakage.

METHODS

A set of human samples from the anastomotic site collected during stapled colorectal anastomosis were used in the study. Transcriptomic profiles were generated for patients who developing anastomotic leakage and case-matched controls with normal anastomotic healing to identify genes and biological processes associated with the development of anastomotic leakage.

RESULTS

The analysis included 22 patients with and 69 without anastomotic leakage. Differential expression analysis showed that 44 genes had adjusted P < 0.050, consisting of two upregulated and 42 downregulated genes. Co-functionality analysis of the 150 most upregulated and 150 most downregulated genes using the GenetICA framework showed formation of clusters of genes with different enrichment for biological pathways. The enriched pathways for the downregulated genes are involved in immune response, angiogenesis, protein metabolism, and collagen cross-linking. The enriched pathways for upregulated genes are involved in cell division.

CONCLUSION

These data indicate that patients who develop anastomotic leakage start the healing process with an error at the level of gene regulation at the time of surgery. Despite normal macroscopic appearance during surgery, the transcriptome data identified several differences in gene expression between patients who developed anastomotic leakage and those who did not. The expressed genes and enriched processes are involved in the different stages of wound healing. These provide therapeutic and diagnostic targets for patients at risk of anastomotic leakage.

Human Adipose Derived Stem Cells Enhance Healing in a Rat Model of Esophageal Injury with Stent

BACKGROUND

Mesenchymal stem cells have been proven to promote cellular recruitment and remodeling during healing. Considering challenges encountered in the healing process of esophageal injury, we sought to evaluate the effect of human adipose derived stem cells (hASC) on esophageal injury with stent and to assess the feasibility of submucosal hASC injection as a mechanism of delivery.

METHODS

An intrabdominal esophagotomy was created in rodents with placement of an expandable fully covered metal esophageal stent. A submucosal injection of 2 × 10⁶ hASC was delivered in experimental animals. Animals were sacrificed on postoperative day 3 (POD3) or 7 (POD7). Macroscopic, immunohistochemical and immunofluorescence analyses were conducted to assess for markers of healing and viability of transplanted cells.

RESULTS

hASC were identified within submucosal and muscular layers with proliferation demonstrated in respective areas on anti-Ki67 stained sections. Lower adhesion and abscess scores were observed in hASC specimens without significant statistical difference. Prevalence of submucosal collagen was increased in samples treated with hASC compared to control, with abundant collagen deposition demonstrated within the POD7 group. Granulation tissue at the site of esophageal injury was more prominent in tissue sections treated with hASC compared to control, with significantly higher density at POD3 (control 1.94 versus hASC 2.83, P < 0.01).

CONCLUSIONS

Presence of hASC at the site of an esophageal injury may enhance wound healing predominantly through increased granulation and decreased inflammation in conjunction with esophageal stent placement. Targeted submucosal injection at the time of esophageal stent placement is an effective delivery method of hASC therapy.

Influence of Age and Sex on Clinical and Therapeutic Features of Laryngopharyngeal Reflux

OBJECTIVE

To explore the influence of age and sex on the clinical presentation and therapeutic response of patients with laryngopharyngeal reflux (LPR).

STUDY DESIGN

Prospective study.

SETTING

Prospective multicenter study of 271 patients with a diagnosis of LPR confirmed by impedance-pH monitoring.

METHODS

Patients were prescribed 6 months of diet changes and a combination of pantoprazole and/or alginate depending on the results of their impedance-pH results. The Reflux Symptom Score (RSS) and Reflux Sign Assessment (RSA) were collected at baseline and at 3 and 6 months posttreatment. Data were explored according to sex and age.

RESULTS

A total of 237 patients completed the evaluations (138 females). On the RSS, patients of the oldest group (>60 years) had lower symptom scores (throat pain, ear pain, odynophagia, chest pain, tongue burning, nausea, halitosis, and indigestion) and lower quality-of-life scores than younger individuals. RSS and RSA outcomes significantly improved from pretreatment to 3 months posttreatment in all groups. Scores on the RSS and RSA continued to improve from 3 to 6 months posttreatment in the elderly group. Females with LPR had a higher score on the RSS at baseline as compared with males. On the RSS, scores significantly improved after 3 months in males and females; however, they continued to improve from 3 to 6 months in the female group.

CONCLUSION

Age and sex may influence the clinical presentation and pre- to posttreatment evolution of symptoms and findings. Age and sex differences could be considered in future therapeutic approaches to guide more effective personalized treatment plans for patients with LPR.

Oral neomycin and bacitracin are effective in preventing surgical site infections in elective colorectal surgery: a multicentre, randomized, parallel, single-blinded trial (COLORAL-1)

Several regimens of oral and intravenous antibiotics (OIVA) have been proposed with contradicting results, and the role of mechanical bowel preparation (MBP) is still controversial. This study aims to assess the effectiveness of oral antibiotic prophylaxis in preventing Surgical Site Infections (SSI) in elective colorectal surgery. In a multicentre trial, we randomized patients undergoing elective colorectal resection surgery, comparing the effectiveness of OIVA versus intravenous antibiotics (IVA) regimens to prevent SSI as the primary outcome (NCT04438655). In addition to intravenous Amoxicillin/Clavulanic, patients in the OIVA group received Oral Neomycin and Bacitracin 24 h before surgery. MBP was administered according to local habits which were not changed for the study. The trial was terminated during the COVID-19 pandemic, as many centers failed to participate as well as the pandemic changed the rules for engaging patients. Two-hundred and four patients were enrolled (100 in the OIVA and 104 in the IVA group); 3 SSIs (3.4%) were registered in the OIVA and 14 (14.4%) in the IVA group (p = 0.010). No difference was observed in terms of anastomotic leak. Multivariable analysis indicated that OIVA reduced the rate of SSI (OR 0.21 / 95% CI 0.06–0.78 / p = 0.019), while BMI is a risk factor of SSI (OR 1.15 / 95% CI 1.01–1.30 p = 0.039). Subgroup analysis indicated that 0/22 patients who underwent OIVA/MBP + vs 13/77 IVA/MBP- experienced an SSI (p = 0.037). The early termination of the study prevents any conclusion regarding the interpretation of the data. Nonetheless, Oral Neomycin/Bacitracin and intravenous beta-lactam/beta-lactamases inhibitors seem to reduce SSI after colorectal resections, although not affecting the anastomotic leak in this trial. The role of MBP requires more investigation.

Impact of Deserosalization on Small Bowel Anastomosis Healing in Swine: A Pilot Study

BACKGROUND

Healing is related to gastrointestinal anastomotic leak, which is a severe and common complication. This study aimed to investigate the feasibility and the impact of deserosalization on healing of jejuno-jejunal anastomoses in an animal model.

MATERIALS AND METHODS

Seven swine underwent three types of side-to-side jejuno-jejunal anastomosis twice and survived seven days. Three different types of jejuno-jejunal side-to-side anastomoses were performed twice at 20-cm distance from each other in each animal: no serosa removal, one-sided, and two-sided serosa removal, respectively. Bursting pressure, tissue hydroxyproline concentration, and pathology scores were evaluated.

RESULTS

Hydroxyproline tissue concentration was a mean±standard deviation of 0.37±0.09, 0.38±0.08, and 0.30±0.05 nmoI/ml respectively (p<0.05). Bursting pressure was a mean±standard deviation of 59.02±8.60, 73.20±11.09, and 100.01±7.49 mmHg, respectively (p<0.001). The histopathological assessment did not find any statistically significant differences.

CONCLUSION

Deserosalization in jejuno-jejunal anastomosis was technically feasible and seemed to improve mechanical strength and collagen deposition in this experimental porcine model. Further investigation is warranted.

Design of a force-measuring setup for colorectal compression anastomosis and first ex-vivo results

Purpose

The introduction of novel endoscopic instruments is essential to reduce trauma in visceral surgery. However, endoscopic device development is hampered by challenges in respecting the dimensional restrictions, due to the narrow access route, and by achieving adequate force transmission. As the overall goal of our research is the development of a patient adaptable, endoscopic anastomosis manipulator, biomechanical and size-related characterization of gastrointestinal organs are needed to determine technical requirements and thresholds to define functional design and load-compatible dimensioning of devices.

Methods

We built an experimental setup to measure colon tissue compression piercing forces. We tested 54 parameter sets, including variations of three tissue fixation configurations, three piercing body configurations (four, eight, twelve spikes) and insertion trajectories of constant velocities (5 mms⁻¹, 10 mms⁻¹,15 mms⁻¹) and constant accelerations (5 mms⁻², 10 mms⁻², 15 mms⁻²) each in 5 samples. Furthermore, anatomical parameters (lumen diameter, tissue thickness) were recorded.

Results

There was no statistically significant difference in insertion forces neither between the trajectory groups, nor for variation of tissue fixation configurations. However, we observed a statistically significant increase in insertion forces for increasing number of spikes. The maximum mean peak forces for four, eight and twelve spikes were 6.4 ± 1.5 N, 13.6 ± 1.4 N and 21.7 ± 5.8 N, respectively. The 5th percentile of specimen lumen diameters and pierced tissue thickness were 24.1 mm and 2.8 mm, and the 95th percentiles 40.1 mm and 4.8 mm, respectively.

Conclusion

The setup enabled reliable biomechanical characterization of colon material, on the base of which design specifications for an endoscopic anastomosis device were derived. The axial implant closure unit must enable axial force transmission of at least 28 N (22 ± 6 N). Implant and applicator diameters must cover a range between 24 and 40 mm, and the implant gap, compressing anastomosed tissue, between 2 and 5 mm.

Hypocalcemia: A possible risk factor for anastomotic leak in digestive surgery

Anastomotic leaks (ALs) remain the most severe complication in digestive surgery, as well as the most consumptive in terms of human and financial resources. There is an abundance of international research which has focused on identifying and correcting risk factors, and on individualized surgical management as well. The most frequent risk factors are male sex, obesity, diabetes, advanced malignant disease, ASA score, perioperative blood loss or perioperative transfusion, long operation time, emergency operation and altered nutritional status. The aim of the present study was to measure the preoperative serum calcium level and to find a possible correlation between calcium levels and the risk of AL occurrence. A retrospective analysis of medical records for 122 patients who underwent surgical gut resection with anastomosis for different pathologies was carried out. Preoperative serum calcium level and the occurrence of AL was noted. The results revealed that the average value of total blood calcium was 8.78 mg/dl, without a significant difference in sex groups. Hypocalcemia was identified in 44 patients (36.1%). AL was identified in 8 patients (6.6%), with a statistically insignificant difference between male and female patients. The average value of blood calcium in the AL patient group was 8.07 mg/dl, while in patients without AL the average value was 8.83 mg/dl. Hypocalcemia, defined as a serum calcium level below 8.5 mg/dl, was observed in 7 of the 8 patients presenting with AL (87.5%) and 37 patients who did not present with AL (32.5%), a significant difference with which to consider and include hypocalcemia in the group of risk factors for AL (P=0.001). In conclusion, preoperative low serum calcium level can represent a risk factor for AL in digestive surgery.

Parent-Reported Feeding Difficulties among Children Born with Esophageal Atresia: Prevalence and Early Risk Factors

INTRODUCTION

 We aimed to describe the prevalence of observable feeding difficulties during mealtimes among children with repaired esophageal atresia (EA) and to determine their early predictors.

MATERIALS AND METHODS

 A survey, based on parents' reports and concerning difficulties in EA children's nutritional intake, was performed with the help of 114 families of 2 to 17-year-old EA patients. Neonatal and clinical/surgical data were collected from medical records. Comparisons were made of the prevalence n (%) of feeding difficulties between children in three age groups (2 to 7 years, 8 to 12 years, or 13 to 17 years of age) using the Mantel-Haenszel chi-square test. Logistic regression identified outcome predictors (odds ratio: 95% confidence interval). Predictors with p ≤ 0.1 in the univariable analysis were included in multiple regression analysis (p < 0.05).

RESULTS

 Seventy-five percent of the young children aged 2 to 7, (median number of feeding difficulties: 2), 61% of school-aged children aged 8 to 12 (median number of feeding difficulties: 1), and 60% patients in the teenage group, aged 13 to 17, (median number of feeding difficulties: 1), reported feeding difficulties. Surgical complications after EA repair independently predicted children having a gastrostomy (p ≤ 0.01), using a food infusion pump (p ≤ 0.01), taking small portions to facilitate eating (p = 0.01), and needing >30 minutes to finish a main meal (p = 0.02). Congenital independent predictors were VACTERL, low birth weight, and preterm birth.

CONCLUSION

 Parentally observed feeding difficulties were commonly reported during early childhood, although prevalence decreases in older age groups. Several congenital and surgical factors were identified as independent predictors of complicated nutritional intake patterns.

Colorectal anastomosis during cytoreductive radical surgery in patients with peritoneal surface malignancies. Validation of a new technique (without stoma) to prevent anastomosis leakage in more than 1000 procedures

OBJECTIVE

To describe a novel end-to-end "true" reinforced stapling colorectal anastomosis and to assess surgical outcomes in a large case series of advanced cancer patients undergoing this procedure. Anastomotic leakage (AL) remains the main concern following surgery for colorectal cancer.

METHODS

Between September 2006 and May 2018, in the context of the Catalonian Program of Peritoneal Carcinomatosis, 1193 consecutive patients with advanced abdominal and/or pelvic tumors were included in a prospective single-center study. They underwent cytoreductive radical surgery (CRS) in most cases combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Among other surgical procedures, 374 patients underwent rectal resection and colorectal/ileorectal anastomosis, whether alone or associated to other digestive anastomosis. Key aspects of colorectal anastomosis technique were: (1) complete dissection and mobilization of the distal third of the rectum, (2) placement of a stitch that included both ends of the linear stapling of the rectal stump that was knotted on the anvil of the circular stapler, (3) "cleaning" the fatty tissue of the intestinal ends, (4) adjustment of the height of staples to the thickness of the intestinal wall, and (5) a second layer of interrupted nonperforating sutures placed circumferentially to reinforce the stapled anastomoses. A diverting stoma was not performed.

RESULTS

According to clinical criteria, of the 1193 patients included, 296 cases underwent CRS (group 1) and 897 cases CRS + HIPEC (group 2). In group 1, 332 surgical procedures were performed, with 248 digestive anastomoses, of which 98 (39.5%) were colorectal anastomoses, associated to other digestive anastomosis in 37 cases. In group 2, 972 surgical procedures were performed, with 707 digestive anastomoses, of which 263 were colorectal (37.2%), 116 were associated with other digestive anastomosis. Ileocolic anastomosis was the most frequently associated digestive anastomosis. 71 major urinary reconstructions, 283 radical hysterectomies and no diverting stoma were performed. Globally, there was only three colo-ileorectal AL (3/374 = 0.8%). The overall 90-day mortality rate was 0.25%.

CONCLUSIONS

A technical modification to create a "true" end-to-end and completely circular reinforced anastomosis effectively prevents anastomotic leakage in patients with advanced tumors undergoing radical resection of the rectum, with no need of diverting stoma.

Evaluation of staple line reinforcement after partial gastrectomy closure in an ex vivo canine model

OBJECTIVE

To determine the influence of stapling on leakage pressures after canine partial gastrectomy.

STUDY DESIGN

Ex vivo study.

SAMPLE POPULATION

Gastric specimens from 24 adult canine cadavers.

METHODS

Partial gastrectomy constructs were assigned to one of three closure techniques (n = 8 per group): group 1, stapled closure with a 90-mm thoracoabdominal stapling device and a 4.8-mm staple cartridge; group 2, hand-sewn double-layer inverting suture closure with 3-0 glycomer 631; and group 3, staple line reinforcement with an inverting Cushing suture pattern. Leakage and pressure testing were performed. Initial leakage pressure (ILP), maximal leakage pressure (MLP), and leakage location were recorded. Significance was set at P < .05.

RESULTS

Placement of a Cushing suture (group 3) increased ILP and MLP by 3.2-fold and 2.8-fold, respectively, compared with stapled closures alone (P < .001). Constructs closed with double-layer suture closure reached ILP and MLP 4.5-fold and threefold greater, respectively, compared with those with stapled closures alone (P < .001). Maximal leakage pressure did not differ between groups 2 and 3 (P = .14). Leakage occurred from the inverting suture line in all constructs of groups 2 and 3 and from staple holes in six of eight group 1 constructs.

CONCLUSION

Double-layer suture closure of canine partial gastrectomies achieved superior biomechanical properties compared with stapled closure techniques. Reinforcing staple closures with an inverting suture line improved resistance to leakage.

CLINICAL SIGNIFICANCE

Reinforcing single-layer closure of partial gastrectomies with an inverting Cushing pattern is recommended to improve resistance to leakage. In vivo investigation is warranted to evaluate influence of closure technique on gastric healing, postoperative stasis, ischemic injury, and postoperative dehiscence.

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.

Evaluation of short-term loop colostomy in dogs using conventional and supporting subcutaneous silicone drain techniques

Objective:

This study aimed at evaluating the supporting and non-supporting loop colostomy techniques in dogs.

Materials and Methods:

In this study, 12 adult healthy mongrel dogs were used to carry out a short-term (21 days) temporary flank loop colostomy. The dogs were divided into two groups (n = 6). In the first group (Con group), conventional stoma fixation was operated without loop support. In the second group [subcutaneous silicone drain (SSD) group], an SSD was used as a supporting bridge. The stoma was fixed by a modified, interrupted seromuscular vertical mattress suture pattern. Both peristomal and stomal complications were recorded.

Results:

Results showed that a total of seven dogs (58%) suffered complications. There was a significant tendency toward less peristomal (p = 0.012) and stomal complications (p = 0.001) in the SSD group. The intensity of pain was significantly (p < 0.05) different between the two groups in the first week post surgery. Comfort with stoma care was significantly (p = 0.015) better in the SSD group, experiencing the best results.

Conclusion:

It is concluded that an appropriate stoma location, using a soft supporting bridge, stoma fixation using modified interrupted neuromuscular vertical mattress sutures, and proper appliance fixation by adhesive tapes and a tight T-shirt may overcome the complications of short-term loop colostomy in dogs and introduce a satisfaction for stoma care.

Platelet-rich fibrin can accelerate the healing of common bile duct anastomosis in a rat

Objectives

This study aimed to evaluate the effect of platelet-rich fibrin (PRF) concentrate on the bile duct anastomosis healing process in rats.

Material and Methods

Thirty male Sprague Dawley (SD) rats were used for the study. The animals were allocated into three groups: Group I Control Group (n=10): Anastomosis to the common bile duct (CBD) with a stent. Group II PRF Group (n=10): Anastomosis to the CBD with a stent and covered with PRF. Group III Sham Group (n=10): Preparation of the common bile duct, no anastomosis. The animals were followed up for 1 month, then sacrificed. Study parameters were adhesions around the anastomosis, thickness of the bridging bile duct tissue over the stent, and histopathologic examination of the bridging bile duct tissue.

Results

CBD anastomosis using a stent caused severe adhesion around the anastomosis, bridging bile duct tissues were weak and histopathologically, healing was incomplete in most of the control animals. However, PRF application significantly reduced the adhesions, increased the quality of the bridging bile duct tissues, and caused complete healing histologically.

Conclusion

PRF is an autologous, easily prepared membrane. The present study findings show that PRF prevents local complications and increases the healing capacity of the bile duct after CBD anastomosis. Therefore, it might be a new treatment option for preventing complications following common bile duct anastomosis in liver transplantation patients.

Indocyanine Green-Enhanced Colorectal Surgery-between Being Superfluous and Being a Game-Changer

Nowadays, surgical innovations incorporate new technological conquests and must be validated by evidence-based medicine. The use of augmented reality-assisted indocyanine green (ICG) fluorescence has generated a myriad of intraoperative applications such as demonstration of key anatomical landmarks, sentinel lymph nodes, and real-time assessment of local blood flow. This paper presents a systematic review of the clinical evidence regarding the applications of ICG near-infrared (NIR) fluorescence in colorectal surgery. After we removed duplicate publications and screened for eligibility, a total of 36 articles were evaluated: 23 on perfusion assessment, 10 on lymph node mapping, and 3 on intraoperative identification of ureters. Lack of homogenous studies, low statistical power, and confounding evidence were found to be common amongst publications supporting the use of ICG in colorectal surgery, raising concerns over this seductive technique's cost efficiency and redundancy. The compiled data showed that ICG NIR fluorescence may be a game-changer in particular situations, as proven for low colorectal anastomosis or lateral pelvic lymph node dissection, but it remains controversial for routine use and sentinel lymph node assessment. Further randomized studies are needed to confirm these conclusions. Future research directions include tumor-targeted fluorescence imaging and digital software for quantitative evaluation of fluorescence.

A prospective study of real-time identification of line of transection in robotic colorectal cancer surgery by ICG

Colorectal cancer is the second most common cancer in women and the third most common cancer in men in the world. Surgical resection is the gold standard treatment and minimally invasive surgery remains the standard of care. Anastomotic leakage is one of the most feared postoperative complications in colorectal surgery. Although several factors have been identified as possible causes of anastomotic leakage (i.e., surgical techniques, patient risk factors, suture material or devices), the complete pathogenesis is still unclear. The reported leak rate ranges from 1 to 30% and increases as the anastomosis is more distal. To date the most widely used methods to assess tissue perfusion includes the surgeon intraoperative visual judgement based on the colour; bleeding edges of resected margins; pulsation and temperature, thereby resulting in either excess or insufficient colonic resection. Earlier studies in colorectal surgery have suggested that assessment of tissue perfusion by the clinical judgment of the operating surgeon underestimated the risk of anastomotic leakage. Indocyanine green (ICG) is a intravenous dye which has shown promise in identifying the bowel vascularity real time. Earlier studies on colorectal cancer have shown that ICG based detection of bowel vascularity is technically possible and has reduced the anastomotic leak rates in 16.7% of patients. We conducted a prospective study on patients with ICG guided bowel perfusion during robotic colorectal cancer surgery. The method is technically easy, reproducible and safe. This technique has changed the intraoperative decision in 88% of patients. Larger studies are needed before this can become the standard of care.

Late anastomotic leakage after anal sphincter saving surgery for rectal cancer: is it different from early anastomotic leakage?

PURPOSE

Although multiple studies have examined anastomotic leakage (AL) after low anterior resection (LAR), their definitions of AL varied, and few have studied late diagnosed AL after surgery. This study aimed to characterize late AL after anal sphincter saving surgery (SSS) for rectal cancer by examining clinical characteristics, risk factors, and management of patients with late AL compared with early AL.

METHODS

Data from January 2005 to December 2014 were collected from a total of 1903 consecutive patients who underwent anal sphincter saving surgery for rectal cancer and were retrospectively reviewed. Late AL was defined as AL diagnosed more than 30 days after surgery. Variables and risk factors associated with early and late diagnosed AL were analyzed by multivariate logistic regression.

RESULTS

Overall, early, and late rates of AL were 13.7%, 6.7%, and 7%, respectively. Receiving neoadjuvant chemoradiotherapy (nCRT) was a risk factor for developing late AL, but not early AL (OR, 3.032; 95% CI, 1.947-4.722; p < 0.001). Protective ileostomy did not protect against late AL. Among the 134 patients with late AL, 26 (19.4%) were classified as asymptomatic and 108 patients (80.6%) as symptomatic. The most frequent symptomatic complications related to late AL were fistula (42 cases, 39.7%), chronic sinus (33 cases, 31.1%), and stenosis (31 cases, 29.2%).

CONCLUSION

Clinical characteristics, risk factors, and management of patients with late AL after SSS were different from early AL. Close attention should be given to consider late AL as the continuation of early AL.

Comparison of Platelet-Rich Plasma-Impregnated Suture Material with Low and High Platelet Concentration to Improve Colonic Anastomotic Wound Healing in Rats

Objective

This study was designed to investigate the impact of using suture material impregnated with platelet-rich plasma (PRP) in different platelet concentrations on colonic anastomotic wound healing in rats.

Methods

A total of 24 Sprague Dawley female rats were separated into 3 groups (n = 8 for each) including the control group (CON; standard vicryl suture repair), the low platelet concentrate PRP group (L-PRP; suture material impregnated with PRP containing average 2.7-fold (range, 2.0 to 3.1) higher amount of platelets vs. control), and the high platelet concentrate PRP group (H-PRP; suture material impregnated with PRP containing average 5.1-fold (range, 4.8 to 5.4) higher amount of platelets vs. control). Rats were sacrificed on the postoperative 7^th day for analysis of colonic anastomosis region including macroscopic observation, measurement of anastomotic bursting pressure (ABP), and the hydroxyproline levels and histopathological findings in colon tissue samples.

Results

Total injury scores were significantly lower in the L-PRP and H-PRP groups than those in the control group (median (range) 13.00 (7.00) and 11.50 (6.00) vs. 15.50 (4.00), p < 0.05 and p < 0.01, respectively). ABP values (180.00 (49.00) vs. 124.00 (62.00) and 121.00 (57.00) mmHg, p < 0.001 for each) and tissue hydroxyproline levels (0.56 (0.37) vs. 0.25 (0.17) and 0.39 (0.10) μg/mg tissue, p < 0.001 and p < 0.05, respectively) were significantly higher in the L-PRP group as compared with those in the control and H-PRP groups.

Conclusion

In conclusion, our findings revealed PRP application to colonic anastomosis sutures to promote the anastomotic healing process. The platelet concentration of PRP seems to have a significant impact on the outcome with superior efficacy of L-PRP over H-PRP in terms of bursting pressures and collagen concentration at the anastomotic site.

Electrospun nanofibers as support for the healing of intestinal anastomoses

The breakdown of intestinal anastomosis is a serious postsurgical complication. The worst complication is anastomotic leakage, resulting in contaminated peritoneal cavity, sepsis, multi-organ failure and even death. In problematic locations like the rectum, the leakage rate has not yet fallen below 10 %. Such a life-threatening condition is the result of impaired healing in the anastomotic wound. It is still vital to find innovative strategies and techniques in order to support regeneration of the anastomotic wound. This paper reviews the surgical techniques and biomaterials used, tested or published. Electrospun nanofibers are introduced as a novel and potential material in gastrointestinal surgery. Nanofibers possess several, unique, physical and chemical properties, that may effectively stimulate cell proliferation and collagen production; a key requirement for the healed intestinal wound.

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.

Development of hyaluronan-based membranes for the healing of intestinal surgical wounds: a preliminary study

Implantable membranes based on alginate and hyaluronic acid (HA) were manufactured to obtain a rapidly resorbing pliable mesh for the in situ administration of HA to intestinal tissue. Morphological analyses of this interpenetrated matrix pointed out a homogeneous polymeric texture while degradation studies demonstrated that the material is able to dissolve in physiological solutions within few days. Biological studies in vitro showed that the membrane is biocompatible towards human dermal fibroblasts and that liquid extracts from the HA-containing membrane can stimulate wound healing. A preliminary in vivo biocompatibility study on rats showed that the membranes in direct contact with the intestine did not elicit any acute adverse reaction or immune response, while only a mild inflammatory reaction was noticed at the mesenteric or serosal region. Overall, these results appear to support the application of these polysaccharide-based materials for intestinal wound healing.

Intra-abdominal complications following intestinal anastomoses by suture and staple techniques in dogs

OBJECTIVE To compare the incidence of intra-abdominal complications in dogs following resection and functional end-to-end stapled anastomosis (FEESA) versus anastomosis with an end-to-end sutured technique for treatment of enteric lesions. DESIGN Multicenter, retrospective descriptive cohort study. ANIMALS 180 dogs. PROCEDURES Medical records of dogs undergoing intestinal resection and anastomosis at 3 nonaffiliated private practice specialty centers were retrospectively reviewed. Preoperative clinical variables, indication for surgery, surgical technique (sutured end-to-end anastomosis vs FEESA), and evidence of postoperative anastomosis site leakage (dehiscence) were recorded. Variables of interest were analyzed for associations with dehiscence. RESULTS Dehiscence rates of sutured and stapled anastomoses were 12 of 93 (13%) and 4 of 87 (5%), respectively; odds of postoperative dehiscence were significantly lower for dogs with FEESAs than for dogs with sutured anastomoses (OR, 0.28; 95% confidence interval, 0.09 to 0.94). Among dogs that underwent surgery for treatment of intestinal dehiscence after surgery at another facility, subsequent dehiscence developed in 3 of 5 with sutured anastomoses and 0 of 11 with stapled anastomoses. Dehiscence rates varied significantly among clinics. No other variable was associated with risk of dehiscence. Eleven of 16 dogs with dehiscence were euthanized without additional surgery. Impaction at the anastomosis site was identified months or years after surgery in 3 dogs (4 anastomosis sites) that had FEESAs. CONCLUSIONS AND CLINICAL RELEVANCE Odds for dehiscence were significantly greater for sutured end-to-end anastomoses than FEESAs, and dogs undergoing surgery for previous dehiscence were significantly more likely to experience a subsequent dehiscence with a sutured anastomosis. However, variability of procedure types and dehiscence rates among clinics suggested further research is needed to confirm these findings. Obstruction at the anastomosis site was identified as a potential long-term complication of FEESA.

The effect of preoperative nutritional status on postoperative complications and overall survival in patients undergoing pelvic exenteration: A multi-disciplinary, multi-institutional cohort study

INTRODUCTION

Optimization of preoperative nutritional status has been recommended and associated with improved outcomes for other oncologic procedures, but has not been studied in patients undergoing pelvic exenteration.

METHODS

A retrospective chart review of 199 patients was conducted. Overall survival (OS) was calculated using the Kaplan-Meier method and multivariate analysis was performed with Cox proportional hazards.

RESULTS

199 patients underwent PE with 61 (31%), 78 (40%) and 58 (29%) patients having colorectal, gynecologic and urologic histological diagnoses, respectively. Median OS following PE was 25 months. Preoperative serum albumin <3.5 g/dL was associated with worsened OS (HR 1.661; 95% CI 1.052-2.624) as well as increased incidence of any postoperative complication (85.9% vs 72.3%, p = 0.034), but was not associated with 90-day mortality (11.3% vs 7.9%, p = 0.457).

CONCLUSION

Poor preoperative nutritional status is associated with increased complications and decreased OS. Surgeons should maximize preoperative nutritional status to improve perioperative outcomes and long-term survival.

Factors Favoring and Impairing Healing of Tracheal Anastomosis

The factors governing successful healing of and impairing of tracheal and bronchial anastomosis are best understood by reviewing the normal histologic changes accompanying healing, governing factors, and biochemical advances made in the last 5 decades. Normal wound healing factors, also relevant to tracheal and bronchial reconstruction, rely on precise handling of tissues without interfering with tissue perfusion, careful selection and placement of sutures, and steps to minimize tension. Impairments of satisfactory healing are well recognized in gastrointestinal surgery and apply to tracheal and carinal resection, and sleeve bronchial resection.

Peripheral vs pedicle division in laparoscopic resection of sigmoid diverticulitis: a 10-year experience

PURPOSE

Laparoscopic rectosigmoid resection is the standard surgical treatment for recurrent sigmoid diverticulitis. However, speaking of mesenterium division, no unique standard procedure is actually provided. Surgeons can perform it at the level of either the sigmoid vessels or the inferior mesenteric vessels. The objective of this study was to compare intra- and postoperative complications of both techniques.

METHODS

From a prospective collected database of patients that underwent elective laparoscopic sigmoid resection between January 2004 and December 2014, a retrospective analysis according to the selected operative technique was performed.

RESULTS

A total of 1016 patients were operated, and a pedicle division of the mesenteric vessels was performed in 280 patients (central group 27.6%) while a peripheral division was performed in 736 patients (peripheral group 72.4%). Comparison of these two groups demonstrated no statistically significant difference regarding age or stage of disease. Thirteen patients (1.3%) developed anastomotic leak; among them, nine belonged to the peripheral group (1.2 vs 1.4% p = 0.794). Twenty-four patients (2.4%) developed postoperative rectal bleeding but only in nine cases was a bleeding of the anastomosis confirmed using endoscopy (seven peripheral group vs two central group, 0.95 vs 0.7% p = 0.712). Moreover, postoperative morbidity did not significantly differ between the two groups. A very low mortality rate was observed, with 2 deaths (both in the peripheral group).

CONCLUSIONS

Ligation of inferior mesenteric vessels does not seem to affect anastomotic healing; both surgical techniques presented similar incidence of anastomotic bleeding. In this analysis, we could not identify any significant difference in overall morbidity and mortality.

Initial Assessment of Mucosal Capture and Leak Pressure After Gastrointestinal Stapling in a Porcine Model

BACKGROUND

Anastomotic leak is a leading cause of morbidity and mortality in gastrointestinal surgery. The serosal aspect of staple lines is commonly observed for integrity, but the mucosal surface and state of mucosa after firing is less often inspected. We sought to assess the degree of mucosal capture when using stapling devices and determine whether incomplete capture influences staple line integrity.

METHODS

Porcine ileum was transected in vivo and staple lines were collected and rated for degree of mucosal capture on a 5-point scale from 1 (mucosa mainly captured on both sides) to 5 (majority of mucosa not captured). Mucosal capture was also assessed in ex vivo staple lines, and fluid leakage pressure and location of first leak was assessed. Stapling devices studied were Echelon Flex GST with 60-mm blue (GST60B) and green (GST60G) cartridges, and Medtronic EndoGIA Universal with Tri-Staple Technology™ with 60 mm medium (EGIA60AMT) reloads (purple).

RESULTS

GST60B and GST60G staple lines produced significantly better mucosal capture scores than the EGIA60AMT staple lines (p < 0.001, in all tests). Compared to EGIA60AMT, leak pressures were 39% higher for GST60B (p < 0.001) and 23% higher for GST60G (p = 0.022). Initial staple line leak site was associated with incomplete mucosal capture 78% of the time.

CONCLUSIONS

There are differences in degree of mucosal capture between commercial staplers, and the devices that produce better mucosal capture had significantly higher leak pressures. Further research is needed to determine the significance of these findings on staple line healing throughout the postoperative period.

Increased Intraoperative Vasopressor Use as Part of an Enhanced Recovery After Surgery Pathway for Pancreatectomy Does Not Increase Risk of Pancreatic Fistula

Purpose: Enhanced recovery after surgery (ERAS) pathways are increasingly implemented. Goal directed fluid therapy (GDFT) is a core component of ERAS pathways that limit excessive volume administration and is associated with increased use of intraoperative vasopressors. Vasopressor effects on anastomotic healing and pancreatic fistula are inconclusive. We hypothesized that intraoperative vasopressor use in an ERAS GDFT algorithm would not increase risk of pancreatic fistulas. Methods: We reviewed all adult patients undergoing pancreatectomy at an academic institution from January 2013 to February 2016, before and after implementation of an ERAS pathway in July 2014. Retrospective chart review was performed. Log-binomial regression, weighted by stabilized inverse probability-of-treatment weights, estimated effect of ERAS and intraoperative vasopressors on fistula risk. Results: One hundred thirty two patients met inclusion criteria: 74 (56.1%) in the ERAS cohort. No significant differences in overall leak risk (risk ratio [RR] 0.89, 95% confidence interval [CI] 0.38-2.09) were observed between the ERAS and pre-ERAS cohorts. Similarly, vasopressor infusions, independent of ERAS pathway, did not significantly increase the risk of anastomotic leaks (RR 1.19, 95% CI 0.52-2.72). Conclusions: Increased use of vasopressor infusions as part of an ERAS pathway for pancreatic surgery is not associated with an increase in the risk of clinically significant pancreatic fistulas.

Role of platelet-rich fibrin on intestinal anastomosis wound healing in a rat

OBJECTIVES

The aim of the present study is to investigate the role of platelet-rich fibrin (PRF) on the intestinal anastomotic wound healing in a mesenteric ischemia/reperfusion (I/R) rat model.

METHODS

Forty male Sprague Dawley rats were allocated into four groups: Group I (n = 10): anastomosis to normal bowel; Group II (n = 10): anastomosis after I/R injury; Group III (n = 10): anastomosis and PRF; Group IV: anastomosis after I/R and PRF. Animals were followed up for 7 days, then sacrificed. Anastomotic complications, anastomosis bursting pressures and histopathologic evaluations of the anastomoses were the study parameters.

RESULTS

The I/R injury caused more anastomotic adhesion and very low anastomotic bursting pressure when compared with the other groups (p < 0.01). Application of PRF onto the bowel, however, dramatically decreased the local complications and significantly increased the anastomosis bursting pressures (p < 0.01). Histologic evaluation of the anastomoses showed almost complete healing in all animals. The mean histologic scores of the animals were not different between the groups.

CONCLUSION

PRF has a beneficial effect on the intestinal healing process by prevention of local complications and increases the tensile strain of the anastomosis. This effect was more prominent, particularly when healing is disrupted. Therefore, we conclude that PRF could be an alternative treatment option to prevent anastomotic complications for elderly, co-morbid and emergency patients.

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.

Local effects of epidermal growth factor on the wound healing in esophageal anastomosis: An experimental study

OBJECTIVE

In this study with the experimental model of primary repair of esophageal atresia(EA), we investigated the effects of the epidermal growth factor(EGF) on wound healing in the anastomosis of EA.

MATERIALS AND METHODS

Forty rabbits that were performed a resection of a 1-cm segment of the cervical esophagus followed by the end-to-end anastomosis were divided into four groups. Group I (7-day group) and III (21-day group), the control groups, had no EGF applied to the anastomosis. In group II (7-day group) and group III (21-day group), all around the anastomoses were locally covered with 100 μg/kg EGF. Group 1, 2 and 3, 4 were sacrificed on the 7th and 21st day, respectively. We investigated and compared with bursting pressure, vascularization around the anastomotic line by histopathology, inflammation, and fibroblast granulation as well as hydroxyproline level by biochemical.

RESULTS

No significant difference was found at vascularization and inflammation between all of the groups (p > 0.05). Considering the critical parameters of the groups, at bursting pressure difference was found between group 1 and 2 as well as 3 and (p < 0.05). At fibroblast granulation and hydroxyproline level, no difference was found between group 1 and 2 (p > 0.05) but the difference between group 3 and 4 (p < 0.05).

CONCLUSION

EGF might be useful in preventing anastomotic leakage of esophageal atresia in primary anastomosis of esophageal atresia by accelerating wound healing process and increasing the stability of the anastomotic line.

Peritoneal fluid biomarkers in the detection of colorectal anastomotic leaks: a systematic review

PURPOSE

Anastomotic leak (AL) in colorectal surgery leads to significant morbidity, mortality and poorer oncological outcomes. Diagnosis of AL is frequently delayed as current methods of detection are not 100% sensitive or specific. 'Biomarkers', such as cytokines and markers of ischaemia, from the milieu of the anastomosis may aid early detection. This paper aims to review the evidence for their role in AL detection, allowing identification of targets for future research.

METHODS

A systematic review was performed using PubMed, MEDLINE and Cochrane Library databases. Papers concerning detection or prediction of AL with biomarkers were identified. References within the papers were used to identify further relevant articles.

RESULTS

Research has taken place in small cohorts with varying definitions of AL. Lactate has consistently been shown to be elevated in patients with intra-abdominal complications and ALs. pH on post-operative day 3 showed excellent specificity. Despite mixed results, a meta-analysis found that the cytokines tumour necrosis factor-α and interleukin-6 were elevated early in AL. Detection of bacteria in drain fluid by RT-PCR has good specificity but a high rate of false positives.

CONCLUSIONS

Peritoneal cytokines, lactate and pH have the potential to identify AL early. The consistency of the results for lactate and pH, alongside the fact that they are easy, quick and inexpensive to test, makes them the most attractive targets. Studies in larger cohorts with standardized definitions of AL are required to clarify their usefulness. Emerging biosensor technology may facilitate the development of small, low-cost and degradable intra-abdominal devices to measure peritoneal fluid biomarkers.