The impact of mesenteric tension on pouch outcome and quality of life in patients undergoing restorative proctocolectomy

Development of a machine learning-based tension measurement method in robotic surgery

BACKGROUND

Over 300,000 colorectal surgeries are performed annually in the U.S. with up to 10% complicated by anastomotic leaks, which cause significant morbidity and mortality. Despite its significant association with anastomotic leaks, tension is predominantly assessed intraoperatively using subjective metrics. This study aims to assess the feasibility of a novel objective method to assess mechanical tension in ex vivo porcine colons.

METHODS

This research was conducted using the da Vinci Research Kit (dVRK). First, a machine learning algorithm based on a long short-term memory neural network was developed to estimate the pulling forces on robotic arms of dVRK. Next, two robotic arms were used to apply upward forces to five ex vivo porcine colon segments. A force sensor was placed underneath the colons to measure ground-truth forces, which were compared to estimated forces calculated by the machine learning algorithm. Root mean square error and Spearman's Correlation were calculated to evaluate force estimation accuracy and correlation between measured and estimated forces, respectively.

RESULTS

Measured forces ranged from 0 to 17.2 N for an average experiment duration of two minutes. The algorithm's force estimates closely tracked the ground-truth sensor measurements with an accuracy of up to 88% and an average accuracy of 74% across all experiments. The estimated and measured forces showed a very strong correlation, with no Spearman's Correlation less than 0.80 across all experiments.

CONCLUSION

This study proposes a machine learning algorithm that estimates colonic tension with a close approximation to ground-truth data from a force sensor. This is the first study to objectively measure tissue tension (and report it in Newtons) using a robot. Our method can be adapted to measure tension on multiple types of tissue and can help prevent surgical complications and mortality.

Impact and Measurement of Mechanical Tension in Bowel Anastomosis: A Scoping Review of the Current Literature

INTRODUCTION

Creating a "tension-free anastomosis" is a fundamental principle in safe bowel surgery. This review aims to summarize the current literature regarding the measurement and impact of tension on bowel anastomoses.

METHODS

This scoping review was conducted using a systematic literature search in the PubMed, SCOPUS, and EMBASE databases. Data were synthesized in tables and summarized paragraphically, with studies assessed using the Newcastle-Ottawa scale.

RESULTS

Out of the 350 studies identified in the initial literature review, 25 were included in this study. Several studies indicated that anastomotic leak and tension are strongly associated, with the presence of tension making leaks up to 10 times more likely. However, no objective and clinically available methods exist to measure tension on bowel anastomosis in humans. Freedom from tension has traditionally been measured via surrogate measures of adequate bowel mobilization and subjective assessment by operating surgeons. Animal and cadaveric studies have been the frontier for objective measurement of wall tension. These studies use tensiometers to measure tension and automated machines or pulley and ratcheting systems to increase tension at specified intervals. However, these methods are universally destructive due to their design of measuring maximal tensile load and are not readily adaptable to the operating room.

CONCLUSIONS

The current literature does not address the objective measurement of bowel tension in live human subjects. Given the importance of tension, developing an objective, safe, intraoperative method to measure bowel wall tension would be a valuable surgical tool.

Pouchitis: pathophysiology and management

Pouchitis is an acute or chronic inflammatory disease of the ileal reservoir. It is common after restorative proctocolectomy with ileal pouch-anal anastomosis, and treatment of chronic antibiotic-refractory pouchitis has proven challenging. Most cases of acute pouchitis evolve into chronic pouchitis. The aetiology of acute pouchitis is likely to be partly related to the gut microbiota, whereas the pathophysiology of chronic pouchitis involves abnormal interactions between genetic disposition, faecal stasis, the gut microbiota, dysregulated host immunity, surgical techniques, ischaemia and mesentery-related factors. Pouchoscopy with biopsy is the most valuable modality for diagnosis, disease monitoring, assessment of treatment response, dysplasia surveillance and delivery of endoscopic therapy. Triggering or risk factors, such as Clostridioides difficile infection and use of non-steroidal anti-inflammatory drugs, should be modified or eradicated. In terms of treatment, acute pouchitis usually responds to oral antibiotics, whereas chronic antibiotic-refractory pouchitis often requires induction and maintenance therapy with integrin, interleukin or tumour necrosis factor inhibitors. Chronic pouchitis with ischaemic features, fistulae or abscesses can be treated with hyperbaric oxygen therapy.

Creation of an institutional preoperative checklist to support clinical risk assessment in patients with ulcerative colitis (UC) considering ileoanal pouch surgery

Background

Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the most established restorative operative approach for patients with ulcerative colitis. It has associated morbidity and the potential for major repercussions on quality of life. As such, patient selection is crucial to its success. The main aim of this paper is to present an institutional preoperative checklist to support clinical risk assessment and patient selection in those considering IPAA.

Methods

A literature review was performed to identify the risk factors associated with surgical complications, decreased functional outcomes/quality of life, and pouch failure after IPAA. Based on this, a preliminary checklist was devised and modified through an iterative process. This was then evaluated by a consensus group comprising the pouch multidisciplinary team (MDT) core members.

Results

The final preoperative checklist includes assessment for risk factors such as gender, advanced age, obesity, comorbidities, sphincteric impairment, Crohn's disease and pelvic radiation therapy. In addition, essential steps in the decision-making process, such as pouch nurse counselling and discussion regarding surgical alternatives, are also included. The last step of the checklist is discussion at a dedicated pouch-MDT.

Discussion

A preoperative checklist may support clinicians with the selection of patients that are suitable for pouch surgery. It also serves as a useful tool to inform the discussion of cases at the MDT meeting.

Intraoperative Techniques for Gaining Ileoanal Pouch Reach

Ileal pouch-anal anastomosis allows for reestablishing gastrointestinal continuity in patients after proctocolectomy. The technical elements of pouch creation and gaining reach into the pelvis are demanding and require a variety of surgical maneuvers to achieve a tension-free anastomosis. We present a brief review of the literature discussing various approaches aimed at improving ileal pouch reach into the low pelvis. Although these techniques are used with different frequencies, they serve as important adjuncts to the gastrointestinal surgeons' armamentarium.

Principles, Preparation, Indications, Precaution, and Damage Control of Endoscopic Therapy in Inflammatory Bowel Disease

Interventional inflammatory bowel disease (IBD) or endoscopic therapy for IBD or IBD surgery-associated complications has emerged as a main treatment modality bridging medical and surgical treatment. It delivers therapy more definitive than medical therapy and less invasive than surgical treatment. The main applications of interventional IBD are strictures, fistulas, abscesses, bleeding, foreign bodies, postoperative complications, and colitis-associated neoplasia. The major endoscopic treatment modalities are balloon dilation, stricturotomy, strictureplasty, fistulotomy, sinusotomy, septectomy, banding ligation, incision and drainage, polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection.

Interventional inflammatory bowel disease: endoscopic therapy of complications of Crohn's disease

Endoscopic therapy for inflammatory bowel diseases (IBD) or IBD surgery-associated complications or namely interventional IBD has become the main treatment modality for Crohn’s disease, bridging medical and surgical treatments. Currently, the main applications of interventional IBD are (i) strictures; (ii) fistulas and abscesses; (iii) bleeding lesions, bezoars, foreign bodies, and polyps; (iv) post-operative complications such as acute and chronic anastomotic leaks; and (v) colitis-associated neoplasia. The endoscopic treatment modalities include balloon dilation, stricturotomy, strictureplasty, fistulotomy, incision and drainage (of fistula and abscess), sinusotomy, septectomy, banding ligation, clipping, polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection. The field of interventional IBD is evolving with a better understanding of the underlying disease process, advances in endoscopic technology, and interest and proper training of next-generation IBD interventionalists.

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.

Fluorescence angiography after vascular ligation to make the ileo-anal pouch reach

The two most essential technical aspects of any gastrointestinal anastomosis are adequate perfusion and sufficient reach. For ileal pouch-anal anastomosis (IPAA), a trade-off exists between these two factors, as lengthening manoeuvers to avoid tension may require vascular ligation. In this technical note, we describe two cases in which we used indocyanine green (ICG) fluorescence angiography (FA) to assess perfusion of the pouch after vascular ligation to acquire sufficient reach. In both cases, FA allowed us to distinguish better between an arterial inflow problem and venous congestion than white light assessment. Both pouches remained viable and no anastomotic leakage occurred. Our results indicate that ICG FA is of great value after vascular ligation to obtain reach during IPAA.

Ileal pouch-anal anastomosis with fluorescence angiography: a case-matched study

AIM

An anastomotic leak in ileoanal pouch surgery may lead to pouch failure. Constructing a tension-free ileal pouch-anal anastomosis (IPAA) reduces this risk but can be technically challenging, balancing pouch vascularization with ileal mesenteric length and site of vessel ligation. Fluorescence angiography (FA) may help the clinician make a more balanced judgement.

METHODS

Thirty-two patients undergoing minimally invasive completion proctectomy with FA-guided IPAA at two academic centres were matched and compared on a 1:1 basis to a historical group undergoing the same procedure without the use of this technique.

RESULTS

Ligation of the ileocolic vessels was safely performed in 15/32 (47%) of FA patients compared with 5/32 (16%) of historical controls. One patient underwent intra-operative IPAA reconstruction after FA detected ischaemia. No anastomotic leak occurred with FA but there was only one in the historical controls (P = 0.31). The postoperative complication rate was similar between the two groups (P = 0.60).

CONCLUSION

FA is applicable to IPAA surgery and may help to reduce perfusion-related anastomotic leaks. A prospective randomized trial is warranted.

Emerging Trends in the Etiology, Prevention, and Treatment of Gastrointestinal Anastomotic Leakage

Anastomotic leaks represent one of the most alarming complications following any gastrointestinal anastomosis due to the substantial effects on post-operative morbidity and mortality of the patient with long-lasting effects on the functional and oncologic outcomes. There is a lack of consensus related to the definition of an anastomotic leak, with a variety of options for prevention and management. A number of patient-related and technical risk factors have been found to be associated with the development of an anastomotic leak and have inspired the development of various preventative measures and technologies. The International Multispecialty Anastomotic Leak Global Improvement Exchange group was convened to establish a consensus on the definition of an anastomotic leak as well as to discuss the various diagnostic, preventative, and management measures currently available.

Early and late surgical outcomes of ileal pouch-anal anastomosis within a defined population in Sweden

OBJECTIVE

Ileal pouch-anal anastomosis (IPAA), has become the procedure of choice in patients requiring reconstructive surgery for ulcerative colitis or familial adenomatous polyposis. The aim of this population-based study was to present data prospectively registered and retrospectively evaluated on the short-term and the long-term results of 124 consecutive IPAA performed chronologically by three surgeons in a single referral centre.

MATERIALS AND METHODS

All patients who underwent IPAA from 1993 to 2012 were included. Early and late morbidity and mortality were evaluated.

RESULTS

Early complications were observed in 25 patients. There was one death from cardiac failure, high output stoma occurred in six patients and wound infection occurred in four patients. Complications were associated with higher BMI (P=0.032). Four patients had to be reoperated. Peroperative bleeding was reduced when using an ultrasonically activated scalpel for the perimuscular dissection (P<0.00001). Clavien-Dindo grade III-V affected five patients. Only one patient developed anastomotic leak and septic complications.Late complications occurred in 61 patients. There was no procedure-related mortality. Pouchitis was the most common complication (n=37). Primary sclerosing cholangitis and age younger than 40 years were associated significantly with a three- and two-fold increased risk of pouchitis, respectively. Small bowel obstruction was the second most common complication (n=16), more common in women (P=0.031). The pouch failure rate was low: 2.4%. Clavien-Dindo grade III-V affected 13 patients.

CONCLUSION

In the hands of experienced high-volume surgeons, IPAA is a safe procedure associated with a relatively low early morbidity as well as an acceptable late morbidity.

Problems after restorative proctocolectomy: assessment and therapy

PURPOSE OF REVIEW

Restorative proctocolectomy with ileal pouch-anal anastomosis is the surgical treatment of choice for patients with ulcerative colitis or familial adenomatous polyposis who require colectomy. Although the surgical procedure significantly improves the patients' quality of life, complications are common. Mechanical or structural complications related to surgical techniques as well as chronic pouchitis are common after the procedure.

RECENT FINDINGS

Recent literature has suggested some of those mechanical complications, along with chronic pouchitis, may share similar risk factors, particularly between anastomotic leak or sinus and chronic pouchitis. Those factors include male gender, obesity, weight gain, and Clostridium difficile infection.

SUMMARY

Mounting clinical evidence suggests that ischemia or excessive fat deposition plays an important role in the development of the surgical procedure-associated mechanical complication as well as chronic antibiotic-refractory pouchitis. Those findings along with the theory of ischemia/fat deposition will shed some light on the pathogenesis of the complex pouch disorders, providing the guidance for the risk stratification, prevention, diagnosis, and management.

Minimally invasive surgery for paediatric inflammatory bowel disease: Personal experience and literature review

The incidence of paediatric inflammatory bowel disease (PIBD) has dramatically increased in the last 20 years. Although first reported in mid 1970s’, diagnostic laparoscopy has started to be routinely adopted in paediatric surgical practice since late 1990s’. Minimally invasive surgery was first limited to diagnostic purposes. After 2002 it was also applied to the radical treatment of PIBD, either Crohn’s disease (CD) or Ulcerative colitis. During the last decade minimally invasive approaches to PIBD have gained popularity and have recently became the “gold standard” for the treatment of such invalidating and troublesome chronic diseases. The authors describe and track the historical evolution of minimally invasive surgery for PIBD and address all available opportunities, including most recent advancements such as robotic surgery, single port approaches and minimally invasive treatment of perianal fistulising CD. A systematic review of all series of PIBD treated with minimally invasive approaches published so far is provided in order to determine the incidence and type of patients’ complications reported up to present days. The authors also describe their experience with minimally invasive surgery for PIBD and will report the results of 104 laparoscopic procedures performed in a series of 61 patients between January 2006 and December 2014.

A think tank of the Italian Society of Colorectal Surgery (SICCR) on the surgical treatment of inflammatory bowel disease using the Delphi method: ulcerative colitis

The majority of patients suffering from ulcerative colitis (UC) are managed successfully with medical treatment, but a relevant number of them will still need surgery at some point in their life. Medical treatments and surgical techniques have changed dramatically in recent years, and available guidelines from relevant societies are rapidly evolving, providing UC experts with updated and valid practical recommendations. However, some aspects of the management of UC patients are still debated, and the application of guidelines in clinical practice may be suboptimal. The Italian Society of Colorectal Surgery (SICCR) sponsored the think tank in order to identify critical aspects of the surgical management of UC in Italy. The present paper reports the results of a think tank of Italian colorectal surgeons concerning surgery for UC and was not developed as an alternative to authoritative guidelines currently available. Members of the SICCR voted on several items proposed by the writing committee, based on evidence from the literature. The results are presented, focusing on points to be implemented. UC management relies on evaluations that need to be individualized, but points of major disagreement reported in this paper should be considered in order to develop strategies to improve the quality of the evidence and the application of guidelines in a clinical setting.