Quantitative analysis of colon perfusion pattern using indocyanine green (ICG) angiography in laparoscopic colorectal surgery. Surg Endosc. 2019;33:1640-1649. [PMID: 30203201 PMCID: PMC6484815 DOI: 10.1007/s00464-018-6439-y]

Simultaneous computer-assisted assessment of mucosal and serosal perfusion in a model of segmental colonic ischemia

BACKGROUND

Fluorescence-based enhanced reality (FLER) enables the quantification of fluorescence signal dynamics, which can be superimposed onto real-time laparoscopic images by using a virtual perfusion cartogram. The current practice of perfusion assessment relies on visualizing the bowel serosa. The aim of this experimental study was to quantify potential differences in mucosal and serosal perfusion levels in an ischemic colon segment.

METHODS

An ischemic colon segment was created in 12 pigs. Simultaneous quantitative mucosal and serosal fluorescence imaging was obtained via intravenous indocyanine green injection (0.2 mg/kg), using two near-infrared camera systems, and computer-assisted FLER analysis. Lactate levels were measured in capillary blood of the colonic wall at seven regions of interest (ROIs) as determined with FLER perfusion cartography: the ischemic zone (I), the proximal and distal vascularized areas (PV, DV), and the 50% perfusion threshold proximally and distally at the mucosal and serosal side (P50M, P50S, D50M, D50S).

RESULTS

The mean ischemic zone as measured (mm) for the mucosal side was significantly larger than the serosal one (56.3 ± 21.3 vs. 40.8 ± 14.9, p = 0.001) with significantly lower lactate values at the mucosal ROIs. There was a significant weak inverse correlation between lactate and slope values for the defined ROIs (r = - 0.2452, p = 0.0246).

CONCLUSIONS

Mucosal ischemic zones were larger than serosal zones. These results suggest that an assessment of bowel perfusion from the serosal side only can underestimate the extent of ischemia. Further studies are required to predict the optimal resection margin and anastomotic site.

Does preoperative enhanced CT predict requirement of intestinal resection in the patients with incarcerated myopectineal hernias containing small bowel?

PURPOSE

Bowel wall enhancement on CT imaging is considered one of the useful features for the prediction of the presence of irreversible ischemic change in patients with small bowel obstruction. However, the applicability of CT imaging in patients with incarcerated hernias has not been investigated in detail. The aim of this retrospective study was to evaluate the feasibility of preoperative CT findings for the prediction of the presence of irreversible ischemic change in patients with incarcerated hernias containing small bowel.

METHODS

Included in this study were 76 patients who underwent surgery for preoperatively diagnosed incarcerated hernias containing small bowel (27 inguinal hernias, 37 femoral hernias and 12 obturator hernias) at our hospital between January 2011 and June 2020. The preoperative clinicoradiological features were compared between the groups, and predictors for intestinal resection were evaluated.

RESULTS

Nineteen patients required intestinal resection (Resection group), and the other 57 patients did not require intestinal resection (Nonresection group). Multivariate analyses revealed that age ≥ 80 years (p = 0.018, odds ratio = 6.604) and the absence of bowel wall enhancement (p = 0.032, odds ratio = 51.200) were independent predictors for intestinal resection. In resected specimens, all patients with an absence of bowel wall enhancement on preoperative enhanced CT had ischemic changes extending beyond the muscularis propria.

CONCLUSIONS

Preoperative enhancement CT yields useful information for the prediction of the presence of irreversible ischemic change in patients with incarcerated hernias containing small bowel.

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.

Intraoperative fluorescence angiography and risk factors of anastomotic leakage in mini-invasive low rectal resections

BACKGROUND

One of the prerequisites for proper healing of the anastomosis after a colorectal resection is adequate blood supply to the connected intestinal segments. It has been proposed that adequate visualization of the blood flow using indocyanine green (ICG) could lead to the reduction in the incidence of anastomotic leakage (AL). The aim of this study was to assess the effectiveness of intraoperative fluorescence angiography (FA) in decreasing the incidence of AL after minimally invasive low anterior resection (LAR) with total mesorectal excision (TME) in rectal cancer patients and to determine predictors of anastomotic leak.

METHODS

From August 2015 to January 2019, data from 100 patients who underwent mini-invasive TME for rectal cancer using FA with indocyanine green (ICG) were prospectively collected and analyzed. They were compared with retrospectively analyzed data from a historical control group operated by one team of surgeons before the introduction of FA from November 2012 to August 2015 (100 patients). All patients from both groups were operated sequentially in one oncological center in Nový Jičín.

RESULTS

The incidence of AL was significantly lower in the ICG group (19% vs. 9%, p = 0.042, χ² test). In fifteen patients in the ICG group (15%), the resection line was moved due to insufficient perfusion. Using Pearson's χ² test, diabetes (p = 0.036) and application of a transanal drain (NoCoil) (p = 0.032) were identified as other risk factors (RFs) for AL.

CONCLUSION

The use of ICG to visualize tissue perfusion in low rectal resections for cancer can lead to a reduction of AL.

Intraoperative fluorescence angiography with indocyanine green: retrospective evaluation and detailed analysis of our single-center 5-year experience focused on colorectal surgery

Objectives

Assessing bowel perfusion with indocyanine green fluorescence angiography (ICG-FA) shows positive effects on anastomotic healing in colorectal surgery.

Methods

A retrospective evaluation of 296 colorectal resections where we performed ICG-FA was undertaken from January 2014 until December 2018. Perfusion of the bowel ends measured with ICG-FA was compared to the visual assessment before and after performing the anastomosis. According to the observations, the operative strategy was confirmed or changed. Sixty-seven low anterior rectal resections (LARs) and 76 right hemicolectomies were evaluated statistically, as ICG-FA was logistically not available for every patient in our service and thus a control group for comparison resulted.

Results

The operative strategy based on the ICG-FA results was changed in 48 patients (16.2%), from which only one developed an anastomotic leakage (AL) (2.1%). The overall AL rate was calculated as 5.4%. Within the 67 patients with LAR, the strategy was changed in 11 patients (16.4%). No leakage was seen in those. In total three AL happened (4.5%), which was three times lower than the AL rate of 13.6% in the control group but statistically not significant. From the 76 right hemicolectomies a strategy change was undertaken in 10 patients (13.2%), from which only one developed an AL. This was the only AL reported in the whole group (1.3%), which was six times lower than the leakage rate of the control group (8.1%). This difference was statistically significant (p=0.032).

Conclusions

Based on the positive impact by ICG-FA on the AL rate, we established the ICG-FA into our clinical routine. Although randomized studies are still missing, ICG-FA can raise patient safety, with only about 10 min longer operating time and almost no additional risk for the patients.

Indocyanine green in the surgical management of endometriosis: A systematic review

INTRODUCTION

Endometriosis is a very common disease that affects up to 10% of the female population. The use of indocyanine green (ICG) dye has been proposed to allow the proper localization of endometriotic lesions during surgery. Our purpose is to offer an overview of near-infrared (NIR)-ICG in the surgical treatment of superficial peritoneal endometriosis and deep infiltrating endometriosis.

MATERIAL AND METHODS

Electronic databases were searched, including MEDLINE, Embase, Web of Science, Scopus, ClinicalTrial.gov, OVID and Cochrane Library. The studies were identified with the use of a mesh combination of the following keywords: "indocyanine green", "endometriosis", "deep endometriosis", "robotic surgery", "laparoscopy", "ureter", "rectosigmoid" from 2000 to May 2020. All articles describing the use of ICG applied to endometriosis surgery were considered for review. Only original papers that reported specific experience data on the topic were included. Moreover, video-articles were included in the analysis. Quality and risk of bias were evaluated by two authors, respectively.

RESULTS

Fifty-three studies were reviewed and reviews or comment articles not reporting original data and original articles lacking specific data on the application of ICG in patients affected by endometriosis were excluded. The quality of the 17 studies included was assessed. Eight studies suggested the usefulness of NIR-ICG as a tool in the detection of endometriosis during surgery, and one randomized controlled trial and one prospective study did not confirm the advantage of its use. Eight studies found that NIR-ICG was useful for the evaluation of vascularization in intestinal anastomoses and ureterolysis after surgery for deep infiltrating endometriosis.

CONCLUSIONS

NIR-ICG appears useful in the evaluation of vascularization in intestinal anastomoses after segmental resection, confirming its role even after ureterolysis for parametrial deep infiltrating endometriosis. However, its usefulness as a tool in the detection of endometriosis during surgery is inconsistent.

Combined microsurgical fluorescence for optimizing resection in refractory empyema and cerebritis

PURPOSE

Due to the generalization of new microsurgical equipment, intraoperative fluorescence techniques have extended in neurosurgical practice, mainly in neurovascular and neuro-oncology patients. The aim of identifying pathological tissue and also differentiating from the normal brain helps neurosurgeons to approach other kinds of intracranial entities such as infections.

METHODS

It is described in the case of an 11-year-old patient who underwent a subdural empyema by performing a craniotomy and evacuation of the purulent collection. After a non-optimal evolution, a frontobasal meningoencephalitis was assessed with cerebral involvement and associated intracranial hypertension. Indocyanine green (ICG) was used in reintervention for demonstrating a great damage of cortical vascularization around the infected area as well as fluorescein (FL), which identified a large area of avascularized tissue.

RESULTS

Both techniques allowed a selective excision of the affected brain parenchyma while preserving viable parenchymal areas. Radiological evolution and clinical outcome were good.

CONCLUSIONS

The identification of vascular patterns in brain lesions and the recognition of viable or necrotized tissues are suitable for a selective resection of the parenchyma, minimizing morbidity. Clinical outcome is related to a safe and effective management of inflammatory and infectious processes.

Computer-assisted quantification and visualization of bowel perfusion using fluorescence-based enhanced reality in left-sided colonic resections

BACKGROUND

Fluorescence-based enhanced reality (FLER) is a computer-based quantification method of fluorescence angiographies to evaluate bowel perfusion. The aim of this prospective trial was to assess the clinical feasibility and to correlate FLER with metabolic markers of perfusion, during colorectal resections.

METHODS

FLER analysis and visualization was performed in 22 patients (diverticulitis n = 17; colorectal cancer n = 5) intra- and extra-abdominally during distal and proximal resection, respectively. The fluorescence signal of indocyanine green (0.2 mg/kg) was captured using a near-infrared camera and computed to create a virtual color-coded cartography. This was overlaid onto the bowel (enhanced reality). It helped to identify regions of interest (ROIs) where samples were subsequently obtained. Resections were performed strictly guided according to clinical decision. On the surgical specimen, samplings were made at different ROIs to measure intestinal lactates (mmol/L) and mitochondria efficiency as acceptor control ratio (ACR).

RESULTS

The native (unquantified) fluorescent signal diffused to obvious ischemic areas during the distal appreciation. Proximally, a lower diffusion of ICG was observed. Five anastomotic complications occurred. The expected values of local capillary lactates were correlated with the measured values both proximally (3.62 ± 2.48 expected vs. 3.17 ± 2.8 actual; rho 0.89; p = 0.0006) and distally (4.5 ± 3 expected vs. 4 ± 2.5 actual; rho 0.73; p = 0.0021). FLER values correlated with ACR at the proximal site (rho 0.76; p = 0.04) and at the ischemic zone (rho 0.71; p = 0.01). In complicated cases, lactates at the proximal resection site were higher (5.8 ± 4.5) as opposed to uncomplicated cases (2.45 ± 1.5; p = 0.008). ACR was reduced proximally in complicated (1.3 ± 0.18) vs. uncomplicated cases (1.68 ± 0.3; p = 0.023).

CONCLUSIONS

FLER allows to image the quantified fluorescence signal in augmented reality and provides a reproducible estimation of bowel perfusion (NCT02626091).

Quantification of fluorescence angiography: Toward a reliable intraoperative assessment of tissue perfusion - A narrative review

BACKGROUND

Accurate intraoperative assessments of tissue perfusion are essential in all forms of surgery. As traditional methods of perfusion assessments are not available during minimally invasive surgery, novel methods are required. Here, fluorescence angiography with indocyanine green has shown promising results. However, to secure objective and reproducible assessments, quantification of the fluorescent signal is essential (Q-ICG). This narrative review aims to provide an overview of the current status and applicability of Q-ICG for intraoperative perfusion assessment.

RESULTS

Both commercial and custom Q-ICG software solutions are available for intraoperative use; however, most studies on Q-ICG have performed post-operative analyses. Q-ICG can be divided into inflow parameters (ttp, t0, slope, and T_1/2max) and intensity parameters (Fmax, PI, and DR). The intensity parameters appear unreliable in clinical settings. In comparison, inflow parameters, mainly slope, and T_1/2max have had superior clinical performance.

CONCLUSION

Intraoperative Q-ICG is clinically available; however, only feasibility studies have been performed, rendering an excellent usability score. Q-ICG in a post-operative setting could detect changes in perfusion following a range of interventions and reflect clinical endpoints, but only if based on inflow parameters. Thus, future studies should include the methodology outlined in this review, emphasizing the use of inflow parameters (slope or T_1/2max), a mass-adjusted ICG dosing, and a fixed camera position.

Indocyanine green fluorescence angiography to evaluate anastomotic perfusion in colorectal surgery

BACKGROUND

The aim of this study was to evaluate the efficacy of indocyanine green (ICG) fluorescence angiography with respect to the anastomotic leakage rate for patients undergoing colorectal operations.

METHODS

This prospective cohort involved patients who underwent colorectal surgery between August 2018 and September 2019. ICG was injected after colonic transection. Vascular perfusion was observed by ICG fluorescence system before completing anastomosis. Data was compared with those by subjective visual evaluation. The primary outcome was anastomotic leakage rate within 30 days from surgery.

RESULTS

A total of 131 patients were enrolled, of which ICG was injected in 63 of them. Demographic data were similar between the two groups. There were two (3.23%) and three (4.35%) anastomotic leaks in the ICG and non-ICG group respectively (p = 1.000). Change of resection plane occurred in one patient in the ICG group. There was no ICG related toxicity or adverse events.

CONCLUSION

ICG fluorescent imaging is a feasible and safe tool to assess colonic vascularisation for patients undergoing colorectal surgery. However, it did not significantly lower the anastomotic leakage rate. ICG should not be routinely used in colorectal surgery before an available large scale randomised controlled trial to prove any clinical benefits.

Intra-arterial versus negative-staining of embryonal resection borders with indocyanine green (ICG) fluorescence for total mesorectal excision in colorectal cancer - an experimental feasibility study in a porcine model

Background: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Laparoscopic lower rectal resections in accordance with the oncological principles are recommended as the gold standard for CRC surgical management. However, the learning curve for adopting these techniques is quite steep and the incomplete resections are predictive of local recurrence. This study was conducted in an attempt to find a way to help surgeons to overcome some of these difficulties and define the right resection margins.Material and methods: As such, we carried out two laparoscopic lower rectal resections in porcine models. The first resection was performed following the ligation and selective infusion of Indocyanine Green (ICG) into the inferior mesenteric artery (IMA), and the second after the ligation of both inferior mesenteric artery and vein (IMV) and systemic intravenous infusion of ICG. Fluorescence was detected in real time by means of an infrared imaging system.Results: Sharp resection margins were defined after intra-arterial infusion, and all the tissues in the IMA basin were colored in the first case. In the second model every organ and tissue was colored except the rectum, urinary bladder and ductus deferens.Conclusions: Although systemic intra-venous application of ICG and negative-staining of the rectum including the mesorectum is much easier compared to laparoscopic inter-arterial perfusion through IMA, image results of selevtive IMA-perfusion appear in sharper discrimination of the several layers. Further investigation should focus on simplifying this technique.

Indocyanine green fluorescence imaging to assess bowel perfusion during totally laparoscopic surgery for colon cancer

BACKGROUND

To retrospectively evaluate the feasibility and safety of intraoperative assessment of bowel perfusion in totally laparoscopic surgery for colon cancer using indocyanine green fluorescence imaging (IGFI).

METHODS

From October 2017 to June 2019, consecutive patients with colon cancer who underwent totally laparoscopic surgery were enrolled retrospectively and grouped into the IGFI group (n = 84) and control group (n = 105). In the IGFI group, indocyanine green (ICG) was injected intravenously, and the bowel perfusion was observed using a fluorescence camera system prior to and after completion of the anastomosis.

RESULTS

The two groups were demographically comparable. The IGFI group exhibited a significantly shorter operative time (p = 0.0374) while intraoperative blood loss did not significantly differ among the groups (p = 0.062). In the IGFI group, average time to perfusion fluorescence was 48.4 ± 14.0 s after ICG injection, and four patients (4.8%) were required to choose a more proximal point of resection due to the lack of adequate fluorescence at the point previously selected. There were no differences in terms of pathological outcomes, postoperative recovery and the postoperative complication rates between the groups (p>0.05).

CONCLUSION

IGFI shows promise as a safe and feasible tool to assess bowel perfusion during a totally laparoscopic surgery for colon cancer and may reduce the operative time.

Efficacy of indocyanine green fluorescence angiography in preventing anastomotic leakage after laparoscopic colorectal cancer surgery

PURPOSE

Some recent studies have suggested that fluorescence angiography with indocyanine green (ICG) might be useful for preventing anastomotic leakage (AL) after laparoscopic colorectal surgery. However, its efficacy has not been proven. We evaluated whether intraoperative ICG fluorescence angiography could decrease the AL rate with laparoscopic colorectal cancer surgery.

METHODS

This retrospective study included patients with colorectal cancer who underwent laparoscopic surgery at our institution between March 2014 and December 2018. Patients were divided into two groups: with or without ICG fluorescence angiography. The primary outcome was the rate of AL.

RESULTS

A total of 488 patients were included: 223 patients in the ICG group and 265 patients in the no-ICG group. In the ICG group, the transection line was changed to a more proximal location in seven patients (3.1%), including one patient with transverse colon surgery and six with rectal surgery. None of these seven patients developed AL. There were 18 ALs (3.7%) overall. The AL rate was 1.8% in the ICG group and 5.3% in the no-ICG group. For colon cancer, there were no significant differences in the AL rate between the groups (p = 0.278). In rectal cancer, the AL rate was significantly lower in the ICG group than in the no-ICG group (3.5% vs. 10.5%, p = 0.041). After propensity score matching, the AL rate was also significantly lower in the ICG group for rectal cancer (p = 0.044).

CONCLUSION

ICG fluorescence angiography can potentially reduce the AL rate with laparoscopic rectal cancer surgery.

Key clinical applications for indocyanine green fluorescence imaging in minimally invasive colorectal surgery

Near-infrared indocyanine green (ICG) fluorescence imaging has gained solid acceptance over the last years, and rightly so, as this technology has so much to offer, especially in the field of minimally invasive surgery. Firm evidence from ongoing and future studies will hopefully transform many of the applications of ICG fluorescence into the standard of care for our patients. This review examines the current status of ICG fluorescence for assessment of bowel perfusion, lymphatic mapping as well as intraoperative localisation of ureter in light of the published academic literature in English.

Clinical utility of transanal indocyanine green near-infrared fluorescence imaging for evaluation of colorectal anastomotic perfusion

BACKGROUND

Although indocyanine green (ICG) fluorescence imaging has been reported to be useful for assessing colorectal perfusion, unstable quantification remains an issue. We performed ICG fluorescence observation from the luminal side and examined the usefulness of the transanal approach.

METHODS

A total of 69 patients who underwent left-side colon surgery were enrolled in this cohort study. After the anastomosis had been constructed, ICG 0.2 mg/kg was injected intravenously. The anastomotic site was then observed by a scope inserted transanally. The following items were examined in the areas of the anastomotic site with the highest- and lowest-fluorescence intensity: maximum fluorescence (Fmax), time from ICG injection to Fmax (Tmax), time from start of dyeing to Fmax (ΔT), and the contrast pattern of the mucosa.

RESULTS

Anastomotic leakage (AL) occurred in nine cases. Tmax and ΔT values of the lowest-fluorescence area in the distal intestine showed significant differences in the cases with AL (P = 0.015 and P = 0.040, respectively). Regarding the contrast pattern of the mucosa of the lowest-fluorescence area in the proximal and distal intestine, the patients in whom the vessels were not depicted in the area had a significantly higher incidence of AL than those in whom vessels were depicted in the area (P = 0.031 and P = 0.030, respectively). Some of the areas in which vessels were not depicted by ICG fluorescence observation from the luminal side corresponded to the points of leakage. There were heterogeneous changes that might not be grasped by observation from the serosal side.

CONCLUSION

Transanal ICG fluorescence imaging can evaluate perfusion over the entire circumference of the anastomosis in detail and aid in assessing the risk of AL. Therefore, the examination of the detailed low-perfusion area enables us to take measures for AL and to search for safer operative managements.

Colonic hypoperfusion following ligation of the inferior mesenteric artery in rectosigmoid colon cancer patients

Purpose

Colon perfusion status is one of the most important factors for the determination of postoperative anastomotic complications. Colonic hypoperfusion can be induced by inferior mesenteric artery (IMA) ligation in some patients. This study aimed to evaluate atherosclerotic risk assessment and vascular parameters of CT angiography as predictors of colonic hypoperfusion.

Methods

This prospective study was conducted at a tertiary referral hospital and included 46 rectosigmoid colon cancer patients undergoing laparoscopic anterior resection between August 2013 to July 2014. Atherosclerotic risk scores were assessed using the Framingham cardiovascular risk score system. The IMA length, branching pattern, atherosclerotic calcification, and intermesenteric artery and mesenteric vascular diameters were evaluated using CT angiography. Mesenteric marginal artery pressures were measured before and after IMA clamping. The mean arterial pressure (MAP) index was calculated by dividing the mesenteric marginal MAP into the systemic MAP to determine the mesenteric hypoperfusion status after IMA clamping. A critically low MAP index was defined as <0.4.

Results

Critically low MAP index (<0.4) was observed in 6 cases (13.0%) after IMA clamping. Atherosclerotic calcification of the IMA and superior mesenteric artery occurred in 11 (23.9%) and 5 patients (10.9%), respectively. Low MAP index was associated with high atherosclerotic risk score and short IMA length, rather than atherosclerotic calcification and other vascular parameters of the major mesenteric arteries. Multivariate analysis indicated that high atherosclerotic risk and short IMA length were independent predictors of critically low MAP index.

Conclusion

Atherosclerotic risk assessment and IMA length were useful predictors of the mesenteric hypoperfusion status following IMA ligation during laparoscopic rectosigmoid colon surgery.

First Experience with Fluorescence in Pediatric Laparoscopy

Background  The use of intraoperative fluorescence images with indocyanine green (ICG) has recently been described as an aid in decision-making during surgical procedures in adults.

We present our first experiences with different laparoscopic procedures performed in children using ICG fluorescence images.

Material and Method  We have used ICG fluorescence imaging technique in varicocele ligation, two nephrectomies, cholecystectomy, and one case of aortocoronary fistula closure. All procedures were performed through a minimally invasive approach. A high definition camera equipped with a visible infrared light source and gray-scale vision technology was used.

After injection of ICG before or during the laparoscopic procedure, precise identification of vascular anatomy and bile duct architecture were easily identified. Fluorescence helped to assess blood flow from the spermatic vessels, define the variability of renal vascularization, and determine the precise location of the aortocoronary fistula. Biliary excretion of the ICG allowed the definition of the biliary tract.

Conclusion  Fluorescein-assisted images allowed a clear definition of the anatomy and safe surgical maneuvers during surgical procedures. The ICG imaging system seems to be simple and safe. Larger and more specific studies are needed to confirm its applicability, expand its indications, and address its advantages and disadvantages.

The significance of intraoperative fluorescence angiography in miniinvasive low rectal resections

Introduction

Anastomotic leak is a very serious complication in colorectal surgery. Tissue perfusion of the anastomosis plays an integral role in its multifactorial etiology. Fluorescence angiography using indocyanine green allows visualization of perfusion in real time.

Aim

To evaluate the effectiveness of intraoperative fluorescence angiography as a tool to decrease the incidence of anastomotic leak after laparoscopic or robotic low resection of the rectum for cancer.

Material and methods

Intraoperative fluorescence angiography was performed sequentially in 50 patients during low rectal resection for cancer with total mesorectal excision, primary anastomosis and protective ileostomy using laparoscopic or robotic technique. The results were compared to a historical control group of 50 patients with the same procedure without the use of fluorescence angiography.

Results

The patient sets were comparable in basic demographic and clinical parameters. Intraoperative visualization of perfusion by fluorescence angiography was achieved in all patients without unwanted side-effects. In 6 (12%) patients, the resection line was adjusted based on the fluorescence angiography. The incidence of anastomotic leak was insignificantly lower in the group with fluorescence angiography (18% vs. 10%), which led to significantly shorter hospital stay. Other postoperative complications were comparable between the two groups.

Conclusions

Fluorescence angiography using indocyanine green is a safe and effective method with the potential of reducing anastomotic leak during minimally invasive low resection of the rectum for cancer.

Intraoperative Fluorescent Angiography Predicts Pharyngocutaneous Fistula After Salvage Laryngectomy

BACKGROUND

Technology to assess tissue perfusion is exciting with translational potential, although data supporting its clinical applications have been lagging. Patients who have undergone radiation are at particular risk of poor tissue perfusion and would benefit from this expanding technology. We designed a prospective clinical trial using intraoperative indocyanine green angiography to evaluate for wound-healing complications in patients undergoing salvage laryngectomy after radiation failure.

PATIENTS AND METHODS

This prospective trial included patients undergoing salvage laryngectomy at a National Cancer Institute-designated tertiary cancer center between 2016 and 2018. After tumor extirpation and prior to reconstruction, 10 mg indocyanine green dye was infused and the fluorescence (F_HYPO) and ingress rate of the pharyngeal mucosa recorded. The primary outcome measure was formation of a pharyngocutaneous fistula (PCF).

RESULTS

Patients who developed a PCF had significantly lower F_HYPO (87 vs 172, p < 0.001) and ingress rates (6.7 vs 15.8, p = 0.043) compared with those who did not develop a fistula. There were no fistulas in patients with F_HYPO > 150 (n = 21) or ingress > 15 (n = 15). There was a 50% fistula rate in patients with F_HYPO ≤ 103 (n = 10) and ingress rate ≤ 6 (n = 6).

CONCLUSIONS

Intraoperative indocyanine green angiography can assess hypoperfusion in patients and predict risk of PCFs after salvage laryngectomy, and can thus intraoperatively risk-stratify patients for postoperative wound-healing complications.