New Technologies to Prevent Anastomotic Leak

Leaks from anastomoses can be a serious complication of any gastrointestinal resection. Leaks lead to increased morbidity, delayed postoperative recovery, and potential delays in adjuvant treatment in cancer cases. Prevention of anastomotic leak has been an area of ongoing research for decades. Methods of assessing bowel perfusion have been developed that may provide forewarning of anastomotic compromise. Physical reinforcement of the anastomosis with buttressing material is an available method employed with the goal of preventing leaks. Liquid-based sealants have also been explored. Lastly, interactions between the gut microbiome and anastomotic healing have been investigated as a mean of manipulating the microenvironment to reduce leak rates. Though no single technology has been successful in eliminating leaks, an understanding of these developing fields will be important for all surgeons who operate on the gastrointestinal tract.

The Use of IndoCyanine Green Fluorescence in the Assessment of Bowel Perfusion in Emergency and Elective Colorectal Surgery

Background The use of Indocyanine Green (ICG) fluorescence is a well-established technique in colorectal surgery for the evaluation of bowel stump perfusion. However there is still no definitive acceptance, except intraoperative macroscopic evidence, with reference to the incidence of anastomotic leakage (AL). The objective of this study is to confirm the same efficacy and reliability of ICG in elective colorectal surgery, and emergency cases, which would be more exposed to complications related to inadequate vascularization.Methods From January 2019 to June 2020, we used ICG to evaluate the perfusion of colonicstumps before and after packaging the anastomosis in right and left hemicolectomy, rectal resection and Hartmann’s reversals.Results A total of 40 patients underwent surgery, 21 (52.50%) had benign pathology and 19 (47.50%) exhibited malignant neoplasia. 13 (32.50%) were emergency surgeries and 27 (67.50%) were planned elective surgeries. In almost all cases, the postoperative course was regular, in only 1 (2.5%) case of TaTME there was an AL. Other complications were not related to the anastomosis, but some validated the excellent perfusion despite episodes of prolonged acute ischemia due to postoperative hemorrhage. Data were finally compared to a control group of 39 patients where the ICG fluorescence was not used.Conclusions The study confirms the validity of the use of ICG fluorescence as a method for intraoperative assessment of bowel perfusion even in emergency conditions and in acute postoperative hemorrhage, detecting an incidence of 2.5% (1 case out of 40) of AL. It’s evident that to validate our results, further randomized studies on a larger data set are required. It would also be beneficial to evaluate quantitatively the fluorescence between the mucous and serous layer, to confirm the reduction of AL rate, the better evaluation of bowel perfusion and, especially in emergency surgeries, the potential reduction of further operations.

EP.TU.826Using Indocyanine Green (ICG) during laparoscopic bowel resections for elective cancer patients reduces anastomotic leaks and length of stay

Introduction Anastomotic leakage (AL) after colorectal surgery is associated with significant morbidity and mortality. Poor perfusion of bowel anastomosis is a significant contributing factor. ICG is a dye administered during laparoscopic surgery to assess bowel perfusion by fluorescent imaging – the aim of this study was to determine whether its use in our centre during elective laparoscopic colorectal cancer resections led to improved patient outcomes. Method Single-centre comparative study of all patients who underwent elective colorectal laparoscopic resections for cancer January 2019- January 2021. Primary outcome investigated was AL. Secondary outcomes: in-patient length of stay, clinical suspicion of AL and post-operative ileus. Cohorts compared with χ2 test. Results 25 patients had resections with ICG, 60 without. None in ICG group, and three in non-ICG group (5%) had AL; p-value 0.29. The ICG group were less likely to have CT for suspected anastomotic leak 12% vs 23.3%, p-value 0.29; and, post-operative ileus 5.3% vs 19.6%, p-value 0.09. Statistically significant reduction in mean inpatient length of stay when ICG used (4.0 days, 95% CI 3.3-4.7) compared to when not used (6.7 days, 95% CI 5.0-8.3). Conclusion Only a small number of previous studies have compared AL rates with and without ICG, finding that its use leads to a significant reduction in AL. While sample size small, our findings supports this. Using ICG also led to a significant reduction in inpatient length of stay. ICG fluorescence angiography is now established as our normal practice for all colorectal resections as a safe, innovative, simple technology.

Management of post-traumatic ischaemic ileal stricture using intraoperative indocyanine green fluorescence-guided resection

Blunt abdominal trauma can affect mesenteric circulation which may lead to bowel strictures. Indocyanine green (ICG) angiography can be used to assess mesenteric blood flow and bowel perfusion as a guide to resect length intraoperatively. But this concept has not been applied to ischaemic bowel strictures. We present a case of ischaemic ileal stricture induced by blunt abdominal trauma which was managed by resection and anastomosis. Intraoperative near-infrared (NIR) ICG angiography was used as a guide to resect the bowel length. This case emphasises that ischaemic bowel strictures should be suspected in patients presenting with intestinal obstruction following trauma. Resection and anastomosis of the affected segment remains the primary treatment modality with excellent outcomes. NIR ICG angiography is a real-time objective and useful resource for assessing bowel perfusion and could be used to determine the length of the segment to be resected in patients with ischaemic bowel stricture.

Fifty Shadows of Mesenteric Ischemia

A 66-year-old female presented to the emergency department with sudden onset of central abdominal pain irradiated to the back. Blood tests were unremarkable. Computed tomography scan showed acute focal ischaemia of small bowel loops sustained by an encircling omental band around a mid ileal loop, which was released on urgent mini-laparotomy. The ischaemic loops were covered with hot moist gauzes for several minutes until the normal luster and peristaltic wave returned. Indocyanine green fluorescence angiography confirmed sufficient bowel perfusion and viability. The patient was discharged 5 days after surgery and did not experience any symptom recurrence up to 6 months later. Mesenteric or colonic ischaemia may respectively affect the small or large intestine. The small intestine is able to compensate for a 75% reduction in mesenteric perfusion for up to 12 hours. If promptly treated, resection may be successfully avoided.

Dynamic Serosal Perfusion Assessment during Colorectal Resection Using Visible Light Spectroscopy

<b><i>Introduction:</i></b> Anastomotic leakage (AL) in colorectal surgery occurs with an incidence of up to 20%. Bowel perfusion is deemed to be one of the most important factors for anastomotic healing. However, not much is known about its variability during colorectal surgery and its impact on the outcome. Therefore, this study aims to evaluate serosal oxygen saturation patterns during colorectal resections with visible light spectroscopy (VLS). <b><i>Materials and Methods:</i></b> Bowel perfusion in patients undergoing left-sided colorectal resections was assessed at different timepoints during surgery using VLS on the colonic serosa. The primary outcome parameter was serosal oxygen saturation (StO₂) at the anastomosis during different timepoints of surgery. <b><i>Results:</i></b> We included 50 patients who underwent colorectal resection for bowel cancer (58%) and diverticular disease (34%). StO₂ at the proximal site of the anastomosis increased significantly throughout the surgery (mean difference 3.61%; 95% CI –6.22 to –1.00; <i>p</i> = 0.008). However, aberrancy from this identified perfusion pattern had no impact on the postoperative outcome. <b><i>Conclusion:</i></b> During colorectal resections, we could demonstrate an increase of the colonic StO₂ throughout surgery. Appearance of AL was not associated with lower StO₂, underlining the multifactorial genesis of developing AL.

A rare complication of laparoscopic adjustable gastric band: acute large bowel obstruction

With many thousands patients carrying laparoscopic adjustable gastric band (LAGB), long-term complications can appear emergently to any surgeon. We present a 64 year-old male who underwent placement of a laparoscopic adjustable gastric band (LAGB) years prior presented to the emergency department with concerning signs of an acute abdomen. Upon imaging review a large bowel obstruction at the level of the sigmoid colon, with ischemic changes, was discovered, caused by the patient’s LAGB catheter. The patient was taken emergently for an exploratory laparotomy during which the LAGB catheter was removed, resulting in restored bowel perfusion. Bowel obstructions are infrequent complications of LAGB. However most commonly they are limited to the small bowel. LAGB catheters resulting in large bowel obstructions are an extremely rare finding. Our review of the literature indicates that this is the first reported cause of a sigmoid obstruction caused by a LAGB. This case brings into view potential complications LAGB that can confront not only bariatric surgeons, but general and acute care surgeons as well. This report illustrates LAGB danger to the colon, and suggests how to manage, perhaps leading to early, life-saving intervention

Novel oxygen saturation imaging endoscopy to assess anastomotic integrity in a porcine ischemia model

Background: Establishing anastomotic integrity is crucial for avoiding anastomotic complications in colorectal surgery. This study aimed to evaluate the safety and feasibility of assessing anastomotic integrity using novel oxygen saturation imaging endoscopy in a porcine ischemia model.Methods: In three pigs, a new endoscope system was used to check the mechanical completeness of the anastomosis and capture the tissue oxygen saturation (StO2) images. This technology can derive the StO2 images from the differences in the absorption coefficient in the visible light region between oxy- and deoxy-hemoglobin. Bowel perfusion at the proximal rectum was assessed before and after the anastomosis, and one minute and thirty minutes after the ligation of the cranial rectal artery (CRA).Results: The completeness of the anastomoses was confirmed by the absence of air leakage. Intraluminal oxygen saturation imaging was successfully performed in all animals. There was no significant difference in the StO2 level before and after the anastomosis (52.6 ± 2.0 vs. 52.0 ± 2.6; p = 0.76, respectively). The StO2 level of the intestine on the oral side of the anastomosis one minute after the CRA ligation was significantly lower than immediately after the anastomosis (15.9 ± 6.0 vs. 52.0 ± 2.6; p = 0.006, respectively). There was no significant difference in the StO2 level between one minute after and thirty minutes after the CRA ligation (15.9 ± 6.0 vs. 12.1 ± 5.3; p = 0.41, respectively).Conclusion: Novel oxygen saturation imaging endoscopy was safe and feasible to assess the anastomotic integrity in the experimental model.

Novel oxygen saturation imaging endoscopy to assess anastomotic integrity in a porcine ischemia model

Background Establishing anastomotic integrity is crucial for avoiding anastomotic complications in colorectal surgery. This study aimed to evaluate the safety and feasibility of assessing anastomotic integrity using novel oxygen saturation imaging endoscopy in a porcine ischemia model. Methods In three pigs, a new endoscope system was used to check the mechanical completeness of the anastomosis and capture the tissue oxygen saturation (StO2) images. This technology can derive the StO2 images from the differences in the absorption coefficient in the visible light region between oxy- and deoxy-hemoglobin. Bowel perfusion at the proximal rectum was assessed before and after the anastomosis, and 1 min and 30 min after the ligation of the cranial rectal artery (CRA). Results The completeness of the anastomoses was confirmed by the absence of air leakage. Intraluminal oxygen saturation imaging was successfully performed in all animals. There was no significant difference in the StO2 level before and after the anastomosis (52.6 ± 2.0 vs. 52.0 ± 2.6; p = 0.76, respectively). The StO2 level of the intestine on the oral side of the anastomosis one minute after the CRA ligation was significantly lower than immediately after the anastomosis (15.9 ± 6.0 vs. 52.0 ± 2.6; p = 0.006, respectively). There was no significant difference in the StO2 level between 1 min after and 30 min after the CRA ligation (15.9 ± 6.0 vs. 12.1 ± 5.3; p = 0.41, respectively). Conclusion Novel oxygen saturation imaging endoscopy was safe and feasible to assess the anastomotic integrity in the experimental model.