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

Surgery for ulcerative colitis

Ulcerative colitis (UC) has a more severe presentation and rapid progression in pediatric patients, resulting in a greater need for surgical intervention compared to adults. Though medical management of UC has advanced with new biologic therapies, surgery continues to play an important role when disease progresses in the form of worsened or persistent symptoms, hemodynamic instability, or sepsis. The goals of surgical management are to restore intestinal continuity with a functional pouch when possible. While the literature has been growing regarding studies of pediatric patients with UC, high level of evidence studies are limited and most recommendations are based on adult studies. Similar to adults, pediatric patients who have ileal pouches created require surveillance for recurrent disease and cancer surveillance. Unique issues for pediatric patients include monitoring of growth and appropriate transition to adult care after adolescence. This review includes indications for surgical management, overview of staged surgical approaches, and the technical details of the three-stage approach.

Fluorescence perfusion assessment of vascular ligation during ileal pouch-anal anastomosis

BACKGROUND

Intraoperative fluorescence angiography (FA) is of potential added value during ileal pouch-anal anastomosis (IPAA), especially after vascular ligation as part of lengthening measures. In this study, time to fluorescent enhancement during FA was evaluated in patients with or without vascular ligation during IPAA.

METHODS

This is a retrospective cohort study of all consecutive patients that underwent FA-guided IPAA between August 2018 and December 2019 in our tertiary referral centre. Vascular ligation was defined as disruption of the ileocolic arcade or ligation of interconnecting terminal ileal branches. FA was performed before and after ileoanal anastomotic reconstruction. During FA, time to fluorescent enhancement was recorded at different sites of the pouch.

RESULTS

Thirty-eight patients [55.3% male, median age 45 years (IQR 24-51 years)] were included, of whom the majority (89.5%) underwent a modified-2-stage restorative proctocolectomy. Vascular ligation was performed in 15 patients (39.5%), and concerned central ligation of the ileocolic arcade in 3 cases, interconnecting branches in 10, and a combination in 2. For the entire cohort, time between indocyanine green (ICG) injection and first fluorescent signal in the pouch was 20 s (IQR 15-31 s) before and 25 s (IQR 20-36 s) after anal anastomotic reconstruction. Time from ICG injection to the first fluorescent signal at the inlet, anvil and blind loop of the pouch were non-significantly prolonged in patients that received vascular ligation.

CONCLUSIONS

Results from this study indicate that time to fluorescence enhancement during FA might be prolonged due to arterial rerouting through the arcade or venous outflow obstruction in case of vascular ligation.

Understanding fluorescence time curves during ileal pouch-anal anastomosis with or without vascular ligation

BACKGROUND

Intraoperative indocyanine green fluorescence angiography (ICG-FA) may be of added value during pouch surgery, in particular after vascular ligations as lengthening maneuver. The aim was to determine quantitative perfusion parameters within the efferent/afferent loop and explore the impact of vascular ligation. Perfusion parameters were also compared in patients with and without anastomotic leakage (AL).

METHODS

All consenting patients that underwent FA-guided ileal pouch-anal anastomosis (IPAA) between July 2020 and December 2021 were included. After intravenous bolus injection of 0.1 mg/kg ICG, the near-infrared camera (Stryker Aim 1688) registered the fluorescence intensity over time. Quantitative analysis of ICG-FA from standardized regions of interests on the pouch was performed using software. Fluorescence parameters were extracted for inflow (T₀, T_max, F_max, slope, Time-to-peak) and outflow (T_90% and T_80%). Change of management related to FA findings and AL rates were recorded.

RESULTS

Twenty-one patients were included, three patients (14%) required vascular ligation to obtain additional length, by ligating terminal ileal branches in two and the ileocolic artery (ICA) in one patient. In nine patients the ICA was already ligated during subtotal colectomy. ICG-FA triggered a change of management in 19% of patients (n = 4/21), all of them had impaired vascular supply (ligated ileocolic/ terminal ileal branches). Overall, patients with intact vascular supply had similar perfusion patterns for the afferent and efferent loop. Pouches with ICA ligation had longer T_max in both afferent as efferent loop than pouches with intact ICA (afferent 51 and efferent 53 versus 41 and 43 s respectively). Mean slope of the efferent loop diminished in ICA ligated patients 1.5(IQR 0.8-4.4) versus 2.2 (1.3-3.6) in ICA intact patients.

CONCLUSION

Quantitative analysis of ICG-FA perfusion during IPAA is feasible and reflects the ligation of the supplying vessels.

Indocyanine Green Fluorescence Guided Surgery in Colorectal Surgery

BACKGROUND

Indocyanine green (ICG) imaging has been increasingly used for intraoperative guidance in colorectal surgery over the past decade. The aim of this study was to review and organize, according to different type of use, all available literature on ICG guided colorectal surgery and highlight areas in need of further research and discuss future perspectives.

METHODS

PubMed, Scopus, and Google Scholar databases were searched systematically through November 2022 for all available studies on fluorescence-guided surgery in colorectal surgery.

RESULTS

Available studies described ICG use in colorectal surgery for perfusion assessment, ureteral and urethral assessment, lymphatic mapping, and hepatic and peritoneal metastases assessment. Although the level of evidence is low, results are promising, especially in the role of ICG in reducing anastomotic leaks.

CONCLUSIONS

ICG imaging is a safe and relatively cheap imaging modality in colorectal surgery, especially for perfusion assessment. Work is underway regarding its use in lymphatic mapping, ureter identification, and the assessment of intraperitoneal metastatic disease.

Robotic Surgery for the Ileal Pouch

BACKGROUND

A robotic approach to total colectomy/proctectomy and ileal pouch reconstruction would seem to be a sensible use of the platform's enhanced reach, visualization, and dexterity.

OBJECTIVE

The study aimed to discuss current published data for robotic ileal pouch surgery.

STUDY SELECTION

The study selection included a paucity of published data to date, representing early learning curves and case series with small numbers.

CONCLUSIONS

Current robotic platforms may offer advantages, particularly in the low pelvis beyond what is found with a laparoscopic approach.

Feasibility of Novel Software-Based Perfusion Indicators for the Ileal J-Pouch-On the Path towards Objective and Quantifiable Intraoperative Perfusion Assessment with Indocyanine Green Near-Infrared Fluorescence

BACKGROUND

In restorative proctocolectomy with ileal J-pouch, perfusion assessment is vital to prevent complications such as anastomotic leak (AL). Indocyanine green near-infrared fluorescence (ICG-NIRF) is gaining popularity, while its interpretation and relevance remain subjective. This study aimed to evaluate a standardized ICG-NIRF imaging protocol combined with a novel, software-based assessment to detect areas of impaired perfusion and a possible correlation with AL of the pouch.

METHODS

In this prospective study, patients undergoing ileal J-pouch for ulcerative colitis at an inflammatory bowel disease (IBD) referral center were included. Intraoperatively, strictly standardized ICG-NIRF visualization was performed and video-recorded. Postoperatively, a specific software was utilized to determine the change in fluorescence intensity per second (i/s) for systematic regions of interest, generating perfusion-time curves and a pixel-to-pixel map. These were analysed in detail and correlated with clinical outcome (primary end point: AL within 30 days; clearly defined and screened for by pouchoscopy).

RESULTS

Four out of 18 included patients developed AL of the ileal pouch-anal anastomosis (IPAA). In the AL group, the perfusion curves on the area adjacent to the IPAA (pouch apex) displayed considerably lower ingress/inflow (median = 1.7; range = 8.5; interquartile-range = 3.8 i/s) and egress/outflow (median = -0.1; range = 0.7; interquartile-range = 0.5 i/s) values than in the non-AL group (ingress: median = 4.3; range = 10.3; interquartile-range = 4.0 i/s); egress: median = (-1.1); range = 3.9; interquartile range = 1.0 i/s). This was confirmed by further novel parameters of pouch perfusion (maximum ingress; maximum egress) and pixel-to-pixel analysis.

CONCLUSIONS

This study presents the feasibility of a novel methodology to precisely assess pouch perfusion with ICG-NIRF, identifying comparable, quantifiable, and objective parameters to potentially detect perfusion-associated complications in surgery in real-time.