Efficacy of the polyglycolic acid sheet for preventing anastomotic leakage in double-stapling technique anastomosis for left-sided colon or rectal cancer surgery: a propensity score-matched study.

BACKGROUND: To prevent anastomotic leakage in patients with left-sided colorectal cancer who underwent double-stapling technique (DST) anastomosis, we investigated a new method: DST anastomosis with a polyglycolic acid (PGA) sheet. This procedure has been shown to have the potential to decrease the rate of anastomotic leakage. However, due to the small number of cases enrolled in our previous study, it was not possible to compare the outcomes of the new and conventional procedures. The aim of this study was to evaluate the effect of the PGA sheet on preventing anastomotic leakage in patients with left-sided colorectal cancer who underwent DST anastomosis by retrospectively comparing the anastomotic leakage rate between the PGA sheet and conventional groups. METHODS: A total of 356 patients with left-sided colorectal cancer who underwent DST anastomosis during surgery at Osaka City University Hospital between January 2016 and April 2022 were enrolled in this study. Propensity score matching was performed to reduce the confounding effects secondary to imbalances in the use of PGA sheets. RESULTS: The PGA sheet was used in 43 cases (PGA sheet group) and it was not used in 313 cases (conventional group). After propensity score matching, the incidence of anastomotic leakage in the PGA sheet group was significantly lower than that in the conventional group. CONCLUSION: DST anastomosis with PGA sheet, which is easy to perform, contributes to the reduction of anastomotic leakage rate by increasing the strength of the anastomotic site.

Use of Polyvinyl Alcohol-Porcine Small Intestine Submucosa Stent in the Prevention of Anastomotic Leaks in the Porcine Colon.

INTRODUCTION: Gastrointestinal anastomoses are performed millions of times per year worldwide. The major complication they share is anastomotic leak. We describe the development and initial safety/efficacy of a novel luminal stent which aims to address this clinical issue. MATERIALS AND METHODS: The stent was created out of two materials, a polyvinyl alcohol core and outer layer of acellular porcine small intestine submucosa. Ten healthy pigs underwent laparotomy, a portion of the colon was transected, and the stent was placed within the colonic lumen at the site of resection. Pigs were sacrificed at the end of postoperative week 2, and postoperative week 4. A portion of the descending colon was resected, and tissue samples from the anastomosis, intentional defect scar, and normal bowel overlying the stent were sent for histopathologic examination. RESULTS: All ten animals survived the study. None developed any clinical signs of obstruction, infection, leakage, fistula, wound complications, or bleeding. No evidence of colonic leak or luminal stenosis/stricture was noted. CONCLUSIONS: The results of this study show that a polyvinyl alcohol/acellular porcine small intestine submucosa stent sewn underneath a colonic anastomosis with a 2 cm intentional defect will result in no anastomotic complications. There were also no complications from placing this stent in any pigs. Additional studies with a control group should be conducted to see if this same stent can be built in different diameters, lengths, and configurations to prevent leaks in other organs. These encouraging results will hopefully lead to decreased leaks and the need for temporary ostomies in humans.

Application of in vivo traction-assisted resection of proximal colon lesions: a case series (with video).

BACKGROUND: Endoscopic submucosal dissection (ESD) is the treatment of choice for colorectal neoplasms in Japan. ESD can completely peel off the lesion and is associated with a significantly lower recurrence rate of colorectal cancers than EMR and is widely used to treat gastrointestinal tumors. This study aimed to evaluate in vivo traction in endoscopic submucosal dissection (ESD) of proximal colon lesions. METHODS: This retrospective study included patients with lesions in the proximal colon who received ESD treatment at Qilu Hospital of Shandong University from June 2018 to December 2020. Patients were divided into two groups according to the in vivo traction method (orthodontic ring or elastic ring) during operation. The operation time, dissection time, proportion of complete resection of lesions, and complications were compared between the two groups. RESULTS: There were 28 patients in this study. In the orthodontic ring group (n = 10), the average lesion diameter was 2.0-2.5 cm, and the average operation and dissection times were 26.5 ± 7.47 and 21.5 ± 7.47 min, respectively. In the elastic ring group (n = 18), the average lesion diameter was 2.5-5.5 cm, and the average operation and dissection times were 27.39 ± 11.83 and 22.39 ± 11.83 min, respectively. All lesions were completely resected in a single operation, and no wound perforation and delayed bleeding occurred. CONCLUSION: In vivo traction-assisted ESD can be used to resect proximal colon lesions in selected patients (precancerous lesions and early colon cancer limited to the mucosa or with a submucosa infiltration depth of < 1000 µm).

Incisional complications after skin closure with n-butyl cyanoacrylate or stainless-steel skin staples in horses undergoing colic surgery.

OBJECTIVE: To compare the prevalence of incisional complications after skin closure with n-butyl cyanoacrylate (NBC) or stainless-steel skin staples (SS) after ventral midline celiotomy for colic surgery in the horse. STUDY DESIGN: Retrospective study (2014-2018). ANIMALS: Two hundred eighteen horses. METHODS: Medical records of horses that underwent exploratory celiotomy for colic were included when the skin was closed with NBC or SS and the horse survived ≥15 days after surgery. Records and a follow-up questionnaire were used to determine in-hospital and posthospital discharge incisional complications. Associations between variables were assessed by using bivariable and multivariable analysis. RESULTS: The cutaneous incision was closed with SS in 113 of 218 (51.8%) horses and with NBC in 105 of 218 (48.2%) horses. Follow-up information was available in 166 of 218 horses. Five horses with incisional complications prior to discharge but without follow-up were included in the overall analysis. Incisional complications were recorded in 17.5% (30/171) of horses, including 19.1% (17/89) of closures with SS and 15.9% (12/82) of closures with NBC (P = .54). Complications occurred before discharge in 14 of 218 (6.4%) horses and after discharge in 16 of 166 (9.6%) horses. Four horses with in-hospital incisional complications (surgical site infection) developed a second complication after discharge (hernia). Packed cell volume was a risk factor for in-hospital incisional complications (P = .04), and in-hospital incisional complications were associated with posthospital discharge incisional complications (P = .01). CONCLUSION: Occurrence of incisional complications did not differ between NBC and SS. CLINICAL SIGNIFICANCE: N-butyl cyanoacrylate is a suitable alternative to SS to close the cutaneous incision for ventral midline celiotomy for colic surgery in the horse.

Multiband mucosectomy for the treatment of challenging non-pedunculated colorectal polyps.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection is the gold standard treatment for non-pedunculated colorectal polyps; however, some specific situations (location behind folds, scarred or flat morphology) can make this technique challenging. We aimed to assess the efficacy and safety of multiband mucosectomy (MBM) for resection of non-pedunculated colorectal polyps. PATIENTS AND METHODS: This was a retrospective study of patients in whom MBM was performed to resect large non-pedunculated colorectal polyps. All procedures were carried out using the Shooter multiband ligator kit (Cook Medical, Limerick, Ireland). A 3-month follow-up colonoscopy was performed in all patients. RESULTS: 10 patients underwent MBM for resection of 10 large (median 33.5 mm) non-pedunculated polyps. A total of 45 MBM sessions were carried out to resect all of the lesions using on average one rubber band per 1.5 cm2 of resected tissue. Complete resection was possible in 9 out of 10 lesions, although en bloc resection was only feasible in one lesion. Follow-up colonoscopy revealed residual adenoma in just one patient. No major complications were registered. CONCLUSIONS: In this small series of patients, MBM proved to be a safe and effective endoscopic resection technique for challenging non-pedunculated colorectal polyps.

2-Octylcyanoacrylate for the prevention of anastomotic leak.

BACKGROUND: Anastomotic leak after colorectal surgery is a significant cause of morbidity and mortality. The aim of this study was to evaluate the impact of a reinforced colo-colonic anastomosis with tissue adhesive, 2-octylcyanoacrylate (2-OCA), on the integrity of anastomotic healing as measured by anastomotic bursting pressure. METHODS: Sixty-eight female Sprague-Dawley rats underwent a rectosigmoid colon transection and a sutured end-to-end anastomosis followed by randomization to receive no further intervention or reinforcement with the tissue adhesive, 2-OCA. After seven postoperative days, a macroscopic assessment of the anastomosis, mechanical assessment to determine anastomotic bursting pressure, and a detailed semi-quantitative histopathologic healing assessment were performed. RESULTS: Thirty-four animals were randomized to each group. Study characteristics did not differ between the groups. There was also no difference in the degree of adhesions present postoperatively. Although there was no difference between the net proximal and distal luminal areas in the two groups (0.37 cm2versus 0.55 cm2, P = 0.26), the 2-OCA group exhibited evidence of stricture in 15% of anastomoses as compared with 3% in the suture-only group (P < 0.0001). Histologically, the presence of only fibroblasts density was statistically more evident in the 2-OCA group compared with the sutured-only anastomosis (P = 0.0183). There was not a significant increase in mechanical strength in the 2-OCA group (238.9 mm Hg) versus in the suture-only group (231.8 mm Hg). There was no difference in the rate of anastomotic leak in the 2-OCA as compared with the suture-only group (9.1 versus 8.8%). CONCLUSIONS: Application of 2-OCA to reinforce a colo-colonic anastomosis clinically provides no benefit to its mechanical strength and detrimentally increases the rate of obstruction and/or stricture in this in vivo model.

Early enteral nutrition within 24 hours of lower gastrointestinal surgery versus later commencement for length of hospital stay and postoperative complications.

BACKGROUND: This is an update of the review last published in 2011. It focuses on early postoperative enteral nutrition after lower gastrointestinal surgery. Traditional management consisted of 'nil by mouth', where patients receive fluids followed by solids after bowel function has returned. Although several trials have reported lower incidence of infectious complications and faster wound healing upon early feeding, other trials have shown no effect. The immediate advantage of energy intake (carbohydrates, protein or fat) could enhance recovery with fewer complications, and this warrants a systematic evaluation. OBJECTIVES: To evaluate whether early commencement of postoperative enteral nutrition (within 24 hours), oral intake and any kind of tube feeding (gastric, duodenal or jejunal), compared with traditional management (delayed nutritional supply) is associated with a shorter length of hospital stay (LoS), fewer complications, mortality and adverse events in patients undergoing lower gastrointestinal surgery (distal to the ligament of Treitz). SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library 2017, issue 10), Ovid MEDLINE (1950 to 15 November 2017), Ovid Embase (1974 to 15 November 2017). We also searched for ongoing trials in ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (15 November 2017). We handsearched reference lists of identified studies and previous systematic reviews. SELECTION CRITERIA: We included randomised controlled trials (RCT) comparing early commencement of enteral nutrition (within 24 hours) with no feeding in adult participants undergoing lower gastrointestinal surgery. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study quality using the Cochrane 'Risk of bias' tool tailored to this review and extracted data. Data analyses were conducted according to the Cochrane recommendations.We rated the quality of evidence according to GRADE.Primary outcomes were LoS and postoperative complications (wound infections, intraabdominal abscesses, anastomotic dehiscence, pneumonia).Secondary outcomes were: mortality, adverse events (nausea, vomiting), and quality of life (QoL).LoS was estimated using mean difference (MD (presented as mean +/- SD). For other outcomes we estimated the common risk ratio (RR) and calculated the associated 95% confidence intervals. For analysis, we used an inverse-variance random-effects model for the primary outcome (LoS) and Mantel-Haenszel random-effects models for the secondary outcomes. We also performed Trial Sequential Analyses (TSA). MAIN RESULTS: We identified 17 RCTs with 1437 participants undergoing lower gastrointestinal surgery. Most studies were at high or unclear risk of bias in two or more domains. Six studies were judged as having low risk of selection bias for random sequence generation and insufficient details were provided for judgement on allocation concealment in all 17 studies. With regards to performance and deception bias; 14 studies reported no attempt to blind participants and blinding of personnel was not discussed either. Only one study was judged as low risk of bias for blinding of outcome assessor. With regards to incomplete outcome data, three studies were judged to be at high risk because they had more than 10% difference in missing data between groups. For selective reporting, nine studies were judged as unclear as protocols were not provided and eight studies had issues with either missing data or incomplete reporting of results.LOS was reported in 16 studies (1346 participants). The mean LoS ranged from four days to 16 days in the early feeding groups and from 6.6 days to 23.5 days in the control groups. Mean difference (MD) in LoS was 1.95 (95% CI, -2.99 to -0.91, P < 0.001) days shorter in the early feeding group. However, there was substantial heterogeneity between included studies (I2 = 81, %, Chi2 = 78.98, P < 0.00001), thus the overall quality of evidence for LoS is low. These results were confirmed by the TSA showing that the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit.We found no differences in the incidence of postoperative complications: wound infection (12 studies, 1181 participants, RR 0.99, 95%CI 0.64 to 1.52, very low-quality evidence), intraabdominal abscesses (6 studies, 554 participants, RR 1.00, 95%CI 0.26 to 3.80, low-quality evidence), anastomotic leakage/dehiscence (13 studies, 1232 participants, RR 0.78, 95%CI 0.38 to 1.61, low-quality evidence; number needed to treat for an additional beneficial outcome (NNTB) = 100), and pneumonia (10 studies, 954 participants, RR 0.88, 95%CI 0.32 to 2.42, low-quality evidence; NNTB = 333).Mortality was reported in 12 studies (1179 participants), and showed no between-group differences (RR = 0.56, 95%CI, 0.21 to 1.52, P = 0.26, I2 = 0%, Chi2 = 3.08, P = 0.96, low-quality evidence). The most commonly reported cause of death was anastomotic leakage, sepsis and acute myocardial infarction.Seven studies (613 participants) reported vomiting (RR 1.23, 95%CI, 0.96 to 1.58, P = 0.10, I2 = 0%, Chi2 = 4.98, P = 0.55, low-quality evidence; number needed to treat for an additional harmful outcome (NNTH) = 19), and two studies (118 participants) reported nausea (RR 0.95, 0.71 to 1.26, low-quality evidence). Four studies reported combined nausea and vomiting (RR 0.94, 95%CI 0.51 to 1.74, very low-quality evidence). One study reported QoL assessment; the scores did not differ between groups at 30 days after discharge on either QoL scale EORTC QLQ-C30 or EORTC QlQ-OV28 (very low-quality evidence). AUTHORS' CONCLUSIONS: This review suggests that early enteral feeding may lead to a reduced postoperative LoS, however cautious interpretation must be taken due to substantial heterogeneity and low-quality evidence. For all other outcomes (postoperative complications, mortality, adverse events, and QoL) the findings are inconclusive, and further trials are justified to enhance the understanding of early feeding for these. In this updated review, only a few additional studies have been included, and these were small and of poor quality.To improve the evidence, future trials should address quality issues and focus on clearly defining and measuring postoperative complications to allow for better comparison between studies. However due to the introduction of fast track protocols which already include an early feeding component, future trials may be challenging. A more feasible trial may be to investigate the effect of differing postoperative energy intake regimens on relevant outcomes.

Reinforcement of the colon anastomosis with cyanoacrylate glue: a porcine model.

BACKGROUND: Previous experimental studies on cyanoacrylate (CA) glue for the prevention of colorectal anastomotic leakage (AL) have shown promising results. The aim of this study was to investigate the effect of CA in prevention of leakage in a porcine model of ischemic colorectal AL. METHODS: Twenty-four animals were divided into four groups of six: (1)ischemic anastomosis with sufficient suture (ISCH), (2)ischemic anastomosis with sufficient suture and CA reinforcement (CA-ISCH), (3)ischemic anastomosis with insufficient suture (ISCH-AI), and (4)ischemic anastomosis with insufficient suture and CA reinforcement (CA-ISCH-AI). In CA groups, N-butyl-2-cyanoacrylate was applied between the colon ends. Anastomotic bursting pressure, abscess formation, and adhesion formation were evaluated on postoperative day 7. Tissue samples were obtained for histologic evaluation of foreign body reaction. RESULTS: The AL rate was 4 of 6 (67%) in the ISCH-AI group compared with none in the other three groups. The ISCH and ISCH-AI groups had significantly higher AL scores compared with the CA groups. The mean anastomotic bursting pressure was 167 ± 54 mm Hg in the ISCH-group versus 213 ± 43 mm Hg in the CA-ISCH-group (P = nonsignificant) and 145 ± 102 mm Hg in the ISCH-AI group versus 187 ± 19 mm Hg in the CA-ISCH-AI group (P = nonsignificant). The average adhesion score was significantly higher in the ISCH group than in the CA-ISCH group (4.2 ± 1.3 versus 1.7 ± 0.82; P = 0.019). Stricture of the anastomosis occurred only in the non-CA groups (3/12, 25%). CONCLUSIONS: Anastomotic reinforcement with CA is effective and safe to prevent leakage in a high-risk colorectal anastomosis in a porcine model.

Impact of tissue adhesives on the prevention of anastomotic leakage of colonic anastomoses: an in vivo study.

BACKGROUND: Tissue adhesives (TA) may be useful to strengthen colorectal anastomoses, thereby preventing anastomotic leakage (AL). Previous studies have identified cyanoacrylate (CA) TAs as the most promising colonic anastomotic sealants. This study investigates the protective effects of sealing colonic anastomoses with various CAs. MATERIALS AND METHODS: Fifty-five Wistar rats underwent laparotomy and transection of the proximal colon. An anastomosis was created with 4 interrupted sutures followed by either application of Histoacryl Flexible, Omnex, Glubran 2, or no TA seal. An additional control group was included with a 12-suture anastomosis and no TA seal. After 7 days, the rats were sacrificed and scored for the presence of AL as the main outcome. Secondary outcomes were the occurrence of bowel obstruction, adhesions, and anastomotic bursting pressure. Histological evaluation was performed. RESULTS: The highest AL rate was found in the Glubran 2 group (7/11), followed by the 4-sutures group without TA (5/11), and the Omnex group (5/11). Histoacryl Flexible showed the lowest AL rate (2/11). In the control group, only one rat showed signs of AL. Histologically, the highest influx of inflammatory cells was found in the 4-suture group without TA and for Omnex and Glubran 2. Histoacryl Flexible caused more mature collagen deposition when compared to the other TA groups. CONCLUSIONS: Histoacryl Flexible showed the lowest leakage rate compared to the other TA groups and to the 4-suture control group. Glubran 2 showed the highest AL rate and a high inflammatory response. Histoacryl Flexible was associated with the presence of more mature collagen and seems to promote anastomotic healing.

A novel endoscopic fluorescent band ligation method for tumor localization.

BACKGROUND: Accurate tumor localization is essential for minimally invasive surgery. This study describes the development of a novel endoscopic fluorescent band ligation method for the rapid and accurate identification of tumor sites during surgery. METHODS AND MATERIALS: The method utilized a fluorescent rubber band, made of indocyanine green (ICG) and a liquid rubber solution mixture, as well as a near-infrared fluorescence laparoscopic system with a dual light source using a high-powered light-emitting diode (LED) and a 785-nm laser diode. The fluorescent rubber bands were endoscopically placed on the mucosae of porcine stomachs and colons. During subsequent conventional laparoscopic stomach and colon surgery, the fluorescent bands were assayed using the near-infrared fluorescence laparoscopy system. RESULTS: The locations of the fluorescent clips were clearly identified on the fluorescence images in real time. The system was able to distinguish the two or three bands marked on the mucosal surfaces of the stomach and colon. Resection margins around the fluorescent bands were sufficient in the resected specimens obtained during stomach and colon surgery. CONCLUSION: These novel endoscopic fluorescent bands could be rapidly and accurately localized during stomach and colon surgery. Use of these bands may make possible the excision of exact target sites during minimally invasive gastrointestinal surgery.

Mechanical strength and rheological properties of tissue adhesives with regard to colorectal anastomosis: an ex vivo study.

OBJECTIVE: To compare mechanical strength and rheology of existing tissue adhesives in a clinically relevant test setup with regard to colorectal anastomosis. BACKGROUND: Little is known on the mechanical strength of tissue adhesives directly after application. Furthermore, rheological profiling may be important in understanding mechanical performance and explaining differences between adhesives. This study provides new data on the mechanical strength and rheology of a comprehensive list of tissue adhesives with regard to colorectal adhesiveness. METHODS: Twelve surgical tissue adhesives were included: 4 cyanoacrylate adhesives (CA), 2 fibrin glues (FG), 3 polyethylene glycol (PEG) adhesives, and 3 albumin-based (AB) adhesives. Tubular rat colonic segments were glued together. Tensile (T), shear (S), and peel (P) strength were measured. Shear storage (G') and shear loss (G″) moduli were also evaluated. RESULTS: CA adhesives were stronger than AB (T: P = 0.017; S: P = 0.064; P: P < 0.001), which, in turn, were stronger than PEG (T: P < 0.001; S: P < 0.001; P: P = 0.018). PEG were stronger than FG for shear (P = 0.013) and comparable for tensile and peel strength (P > 0.05). Within-group variation was smallest for CA. Mechanical strength correlated strongly between performed tests. Rheological properties (G' and G″) correlated strongly with mechanical strength for all adhesives combined. CONCLUSIONS: CA adhesives are the strongest and most homogenous group in terms of mechanical strength. Hydrogels (FG, AB) are heterogeneous, with lower mechanical strength than CA. FG are mechanically the weakest adhesives. Rheological profiles correlate to mechanical strength and may be useful for predicting mechanical performance.

COMPRES: a prospective postmarketing evaluation of the compression anastomosis ring CAR 27(™) /ColonRing(™).

AIM: Preclinical studies have suggested that nitinol-based compression anastomosis might be a viable solution to anastomotic leak following low anterior resection. A prospective multicentre open label study was therefore designed to evaluate the performance of the ColonRing(™) in (low) colorectal anastomosis. METHOD: The primary outcome measure was anastomotic leakage. Patients were recruited at 13 different colorectal surgical units in Europe, the United States and Israel. Institutional review board approval was obtained. RESULTS: Between 21 March 2010 and 3 August 2011, 266 patients completed the study protocol. The overall anastomotic leakage rate was 5.3% for all anastomoses, including a rate of 3.1% for low anastomoses. Septic anastomotic complications occurred in 8.3% of all anastomoses and 8.2% of low anastomoses. CONCLUSION: Nitinol compression anastomosis is safe, effective and easy to use and may offer an advantage for low colorectal anastomosis. A prospective randomized trial comparing ColonRing(™) with conventional stapling is needed.

Ultrapure alginate anti-adhesion gel does not impair colon anastomotic strength.

BACKGROUND: Ultrapure alginate gel is promising in terms of adhesion prevention. Because anti-adhesive barriers have been shown to disturb healing of bowel anastomoses, the effect of ultrapure alginate gel on the repair of colon anastomoses was studied. MATERIALS AND METHODS: In 102 male Wistar rats, a 0.5-cm segment was resected from the descending colon and continuity was restored by an inverted single-layer end-to-end anastomosis. Animals were randomized into a control, an alginate gel, and a sodium hyaluronate carboxymethyl cellulose film group, each n = 34. Half of each group was sacrificed at day 3 and 7 postoperatively. Anastomotic strength was assessed by measuring both bursting pressure and breaking strength. Hydroxyproline content was measured and histologic analysis was performed. The incidence of adhesion and abscess formation was scored at sacrifice. RESULTS: No difference in either anastomotic-bursting pressure or breaking strength was found between experimental groups and the controls at any time point. Both the incidence of adhesion formation (35% versus 71%, P = 0.007) and the adhesion score (0.38 versus 0.79, P = 0.009) were significantly lower in the alginate gel group than in the controls. The abscess rate was higher (46% versus 18%, P = 0.030) in the hyaluronate carboxymethyl cellulose group than in the controls and unchanged in the alginate gel group. CONCLUSIONS: While reducing adhesion formation, ultrapure alginate gel does not interfere with the development of colonic anastomotic strength during the crucial early healing period.

The prevention of colorectal anastomotic leakage with tissue adhesives in a contaminated environment is associated with the presence of anti-inflammatory macrophages.

BACKGROUND: Colorectal anastomoses created in a contaminated environment result in a high leakage rate. This study investigated whether using anastomotic sealants (TissuCol(®), Histoacryl(®) Flex, and Duraseal(®)) prevents leakage in a rat peritonitis model. STUDY DESIGN: Sixty-seven Wistar rats were divided into control and experimental groups (TissuCol, Histoacryl, and Duraseal groups). Peritonitis was induced 1 day before surgery with the cecal ligation puncture model. On day 0, colonic anastomosis was constructed with sutures and then sealed with no adhesive (control group) or one select adhesive (experimental groups). Bursting pressure, abscess formation, and adhesion severity were evaluated on day 3 or day 14. Hematoxylin and eosin staining and immunohistochemical staining for CD4, CD8, CD206, and iNOS were performed. RESULTS: On day 3, bursting pressures of the TissuCol group (120.1 ± 25.3 mmHg), Histoacryl group (117.3 ± 20.2 mmHg), and Duraseal group (123.6 ± 35.4 mmHg) were significantly higher than the that of the control group (24.4 ± 31.7 mmHg, p < 0.001). Abscesses around the anastomosis were found in the control group (6/7) and Duraseal group (2/9) but not in the TissuCol group or Histoacryl group. A higher number of CD206+ cells (M2 macrophages), a lower number of iNOS+ cells (M1 macrophages), a higher M2/M1 index, and a higher CD4+/CD8+ index were seen at the anastomotic site in all experimental groups compared with the control group on day 3. On day 14, abscesses were only found in the control group. Adhesion severity in the Duraseal group was significantly lower than that in the control group (p = 0.001). CONCLUSIONS: Anastomotic sealing using TissuCol(®), Histoacryl(®) Flex, or Duraseal(®) seems to be an effective and safe option to prevent leakage in contaminated colorectal surgery. The presence of large numbers of anti-inflammatory macrophages seems to be involved in preventing the leakage.

Feasibility experiment of a novel deformable self-assembled magnetic anastomosis ring (DSAMAR) for gastrointestinal anastomosis through a natural orifice.

Although the application of magnetic compression anastomosis is becoming increasingly widespread, the magnets used in earlier studies were mostly in the shape of a whole ring. Hence, a deformable self-assembled magnetic anastomosis ring (DSAMAR) was designed in this study for gastrointestinal anastomosis. Furthermore, its feasibility was studied using a beagle model. The designed DSAMAR comprised 10 trapezoidal magnetic units. Twelve beagles were used as animal models, and DSAMARs were inserted into the stomach and colon through the mouth and anus, respectively, via endoscopy to achieve gastrocolic magnamosis. Surgical time, number of failed deformations, survival rate of the animals, and the time of magnet discharge were documented. A month later, specimens of the anastomosis were obtained and observed with the naked eye as well as microscopically. In the gastrocolic anastomosis of the 12 beagles, the procedure took 65-120 min. Although a deformation failure occurred during the operation in one of the beagles, it was successful after repositioning. The anastomosis was formed after the magnet fell off 12-18 days after the operation. Naked eye and microscopic observations revealed that the anastomotic specimens obtained 1 month later were well-formed, smooth, and flat. DSAMAR is thus feasible for gastrointestinal anastomosis under full endoscopy via the natural orifice.

Outcome and predictive factors for perforation in orthodontic rubber band-assisted endoscopic submucosal dissection of fibrotic colorectal lesions.

Endoscopic submucosal dissection (ESD) of fibrotic colorectal lesions is difficult and has a high complication rate. There are only a few reports on the utility of orthodontic rubber band (ORB) traction in reducing the difficulty of this procedure. This study aimed to investigate the risk factors for perforation when applying ORB traction during ESD of fibrotic colorectal lesions. We continuously collected the clinical data of 119 patients with fibrotic colorectal lesions who underwent ESD with ORB and clip traction between January 2019 and January 2024. Possible risk factors for perforation were analyzed. The median ORB-ESD operative time was 40 (IQR 28-62) min, and the en bloc and R0 resection rates were 94.1% and 84.0%, respectively. Perforation occurred in 16 of 119 patients (13.4%). The lesion size, lesion at the right half of the colon or across an intestinal plica, the degree of fibrosis, operation time, and the surgeon's experience were associated with perforation during ORB-ESD (P < 0.05). Multivariate logistic regression analysis showed that lesions in the right colon (OR 9.027; 95% CI 1.807-45.098; P = 0.007) and those across an intestinal plica (OR 7.771; 95% CI 1.298-46.536; P = 0.025) were independent risk factors for perforation during ORB-ESD. ORB-ESD is an effective and feasible approach to treat fibrotic colorectal lesions. Adequate preoperative evaluation is required for lesions in the right colon and across intestinal plicas to mitigate the risk of perforation.

Comparison between tungsten and steel polypectomy snares: evaluation of depth of colonic thermal wall injury in a pig model.

BACKGROUND AND STUDY AIMS: Thermal injury of the colonic wall during polypectomy may induce complications such as bleeding and perforation. To date, the role of the snare material in these injuries has not been examined. The aim of this study was to evaluate the depth of colonic post-polypectomy thermal wall injury induced by tungsten and steel endoscopic snares, in an effort to reduce electrosurgery-related complications. MATERIALS AND METHODS: This was a single tertiary center experimental study in a porcine model. A total of 90 polypectomies where performed in three live pigs under general anesthesia, using both steel and tungsten snares by cut, coagulation, and blend current modes. The pigs were then euthanized and their colons examined histologically. RESULTS: Steel snares induced significantly deeper tissue injury than tungsten snares in the pure cut mode (Pearson χ2 = 6.136, P = 0.013). The ordinal logistic regression analysis showed that the current mode and snare material were significantly associated with the ordinal score for the depth of injury. Thus, cut mode was positively associated with a lower score and coagulation mode with a higher score. In addition, tungsten was significantly associated with a lower depth of tissue injury. CONCLUSIONS: Due to its inherent electrical properties, tungsten is very well suited for manufacture into electrosurgical endoscopic devices. Thus, tungsten snares may be advantageous for routine use in endoscopic polypectomy, although further studies are needed to confirm these promising findings in human patients.