Fluorescence angiography with indocyanine green (ICG) to evaluate anastomosis in colorectal surgery: where does it have more value?

Systematic review on the use of artificial intelligence to identify anatomical structures during laparoscopic cholecystectomy: a tool towards the future

PURPOSE

Bile duct injury (BDI) during laparoscopic cholecystectomy (LC) is a dreaded complication. Artificial intelligence (AI) has recently been introduced in surgery. This systematic review aims to investigate whether AI can guide surgeons in identifying anatomical structures to facilitate safer dissection during LC.

METHODS

Following PROSPERO registration CRD-42023478754, a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant systematic search of MEDLINE (via PubMed), EMBASE, and Web of Science databases was conducted.

RESULTS

Out of 2304 articles identified, twenty-five were included in the analysis. The mean average precision for biliary structures detection reported in the included studies reaches 98%. The mean intersection over union ranges from 0.5 to 0.7, and the mean Dice/F1 spatial correlation index was greater than 0.7/1. AI system provided a change in the annotations in 27% of the cases, and 70% of these shifts were considered safer changes. The contribution to preventing BDI was reported at 3.65/4.

CONCLUSIONS

Although studies on the use of AI during LC are few and very heterogeneous, AI has the potential to identify anatomical structures, thereby guiding surgeons towards safer LC procedures.

Laparoscopic right hemicolectomy with complete mesocolon excision and cranial approach

BACKGROUND

Complete mesocolon excision (CME) and D3-lymphadenectomy concepts have gained popularity for the surgical treatment of right colon cancer in comparison to the conventional laparoscopic right hemicolectomy (CLRH). The rationale of CME is to dissect the embryological planes between the mesenteric plane and the parietal fascia to remove the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains lymph nodes, the central vascular ligation, and adequate bowel length to remove involved pericolic lymph nodes in the longitudinal direction, having as the main goal to improve the oncological results. CME with D3-lymphadenectomy is challenge since involves the excision of the lymph adipose tissue covering the medial edge of the superior mesenteric vein (SMV) (trunk of Gillot, TG), and the gastrocolic trunk of Henle (GTH). We describe a LRH with CME using a cranial approach allowing an easier central vessels origin identification.

TECHNIQUE

Through the supramesocolic approach, gastrocolic ligament is opened and the GTH and the middle colic artery (MCA) and vein (MCV) origins are identified. Hepatic flexure is mobilized, and a gauze is placed above the mesenteric vessels. Then, the SMV is identified, dividing the ileocolic vessels origin. The plane between the Gerota and Toldt fascias is opened, identifying duodenum, pancreas, and the gauze previously placed. Following this plane and the SMV along the TG, the GTH and its branches are identified. The superior right colic vein, and the MCA and MCV right branches are divided. After that, colon is fully mobilized laterally opening the parietocolic gutter and an intracorporeal anastomosis is performed.

CONCLUSION

CME could lead to an improvement of oncological results due to a wider mesocolic excision in comparison to conventional D2-lymphadenectomy. Cranial approach facilitates the vessels origin identification to perform a true central ligation.

Analysis of outcomes of penetrating colonic injuries managed with or without fecal diversion

Traumatic colorectal injuries can be managed by either fecal diversion or primary repair / resection and anastomosis. We aimed to study differences in outcomes in adult patients managed with or without fecal diversion at time of initial operation. The National Trauma Databank (NTDB) was used to identify adult patients (ages 18-64 years) with penetrating colonic injuries for the years 2013-2015. We included patients with Injury Severity Score (ISS) of 9-24 excluding patients with concomitant extra-abdominal Abbreviated Injury Scale (AIS) score of 3 or more. Subjects arriving without signs of life, expiring in ER or with missing data were excluded. Data was collected for age, gender, vital signs on presentation, discharge disposition and length of stay (LOS). Patients were divided into two groups based on whether or not fecal diversion was performed within 1 day of presentation. Primary outcome assessed was in-hospital mortality and unplanned return to OR. Secondary outcomes were acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), deep vein thrombosis (DVT), pulmonary embolism (PE), pneumonia, organ surgical site infection (SSI), deep SSI, severe sepsis and unplanned intubation. Statistical analysis was conducted using SPSS for windows. P-value < 0.05 was considered statistically significant. Of 2,598,467 patients, 5344 (0.21%) sustained a penetrating colonic injury. 2339 (43.8%) patients met criteria for age, ISS, AIS, signs of life and ED outcome. 173 patients underwent fecal diversion within 24 h of presentation (Group 1) while 708 did not (Group 2). Patients with missing data were excluded leaving 162 patients in Group 1 and 657 patients in Group 2. Groups 1 and 2 were noted to be similar in terms of ISS (median of 10 in both), age (median of 31 vs 29 years), percentage of male patients (85.2% vs 87.8%; p = 0.44), mean systolic blood pressure (127 mmHg vs 126 mmHg; p = 0.54), mean pulse rate (95.4 vs 94.5; p = 0.60) and mean respiratory rate (20.4 vs 20.1; p = 0.56) respectively. Median LOS was 10 days in both groups. No statistically significant differences were found between groups 1 and 2 in the primary outcomes of in-hospital mortality (2.4% vs 3.5%; OR: 1.43; 95% confidence interval (CI): 0.49-4.20) or unplanned return to OR (4.3% vs 7.8%; OR: 1.86; 95% CI: 0.83-4.19). No statistically significant differences were noted between groups 1 and 2 in the secondary outcomes of AKI (3.7% vs 3.8%; OR: 1.03; 95% CI 0.41-2.55), ARDS (1.2% VS 1.7%; OR: 1.36; 95% CI 0.30-6.21), DVT (1.9% vs 4.0%; OR: 2.18; 95% CI 0.65-7.31), PE (1.9% vs 2.0%; OR: 1.07; 95% CI 0.30-3.80), pneumonia (4.9% vs 5.3%; OR: 1.08; 95% CI 0.49-2.38), organ SSI (3.7% vs 7.0%; OR: 1.96; 95% CI: 0.82-4.67), deep SSI (3.7% vs 4.4%; OR: 1.20, 95% CI 0.49-2.94), severe sepsis (3.7% vs 3.3%; OR: 0.90; 95% CI: 0.36-2.26) or unplanned intubation (1.9% vs 1.7%; OR: 0.90; 95% CI 0.25-3.27). Adult patients with penetrating colonic injuries with ISS 9-24 in the absence of serious extra-abdominal injury who undergo surgery within 24 h of presentation do not seem to derive a statistically significant benefit from fecal diversion in terms of post-operative complications and mortality. In more severely injured patients fecal diversion may continue to provide a benefit.

[Modern approaches and technologies to prevent anastomotic leakage in the gastrointestinal tract]

The healing of gastrointestinal anastomoses is a complex biological process influenced by numerous factors. Various strategies to support healing and prevent anastomotic leakage (AL) exist, encompassing preoperative, intraoperative and postoperative measures. Preoperative interventions aim to optimize the patient and the tissue environment, particularly the gut microbiome. Intraoperative measures are technical in nature and include the choice of surgical access, the anastomotic technique and anastomotic reinforcement. Various procedures of the intraoperative diagnostics enable identification of such anastomoses requiring additional protective measures. Recently, indocyanine green (ICG) fluoroscopy has become established for evaluation of tissue perfusion, while newer techniques such as spectral microscopy offer promising possibilities. Postoperative diagnostic methods aim to identify potential AL as early as possible to enable initiation of therapeutic steps even before the onset of symptoms. These procedures range from various imaging techniques to innovative bioresorbable, pH-sensitive implants for early AL detection. Due to the multifactorial genesis of AL and the diverse technical possibilities, no single method will become established for prevention of AL. Instead, a combination of measures will ultimately lead to optimal anastomotic healing. The use of artificial intelligence and analyses based on the data promises a better interpretation of the vast amount of data and therefore to be able to provide general recommendations.

Indocyanine green fluorescence angiography in colorectal surgery: A retrospective case-control analysis in Mexico

INTRODUCTION AND AIMS

An anastomotic leak is one of the most dreaded complications in colorectal surgery because it increases postoperative morbidity and mortality. The aim of the present study was to identify whether indocyanine green fluorescence angiography (ICGFA) reduced the anastomotic dehiscence rate in colorectal surgery.

MATERIAL AND METHODS

A retrospective study on patients that underwent colorectal surgery with colonic resection or low anterior resection and primary anastomosis, within the time frame of January 2019 and September 2021, was conducted. The patients were divided into the case group, in which ICGFA was performed for the intraoperative evaluation of blood perfusion at the anastomosis site, and the control group, in which ICGFA was not utilized.

RESULTS

A total of 168 medical records were reviewed, resulting in 83 cases and 85 controls. Inadequate perfusion that required changing the surgical site of the anastomosis was identified in 4.8% of the case group (n = 4). A trend toward reducing the leak rate with ICGFA was identified (6% [n = 5] in the cases vs 7.1% in the controls [n = 6] [p = 0.999]). The patients that underwent anastomosis site change due to inadequate perfusion had a 0% leak rate.

CONCLUSIONS

ICGFA as a method to evaluate intraoperative blood perfusion showed a trend toward reducing the incidence of anastomotic leak in colorectal surgery.

Indocyanine green fluorescence angiography could reduce the risk of anastomotic leakage in rectal cancer surgery: a systematic review and meta-analysis of randomized controlled trials

AIM

Several papers have shown that use of indocyanine green (ICG) decreases incidence of anastomotic leakage (AL) during colonic surgery, but no clear evidence has been found for rectal cancer surgery. Therefore, with this systematic review and meta-analysis of randomized controlled trials (RCTs) we aimed to assess if ICG could also reduce risk of AL in rectal cancer surgery.

METHOD

PubMed, Scopus, CINAHL and Cochrane databases were searched for RCTs assessing the effect of intraoperative ICG on the incidence of AL of the colorectal anastomosis. Pooled relative risk (RR) and pooled risk difference (RD) were obtained using models with random effects. Risk of bias was evaluated with the Rob2 tool and the quality of evidence was assessed using the GRADE Pro tool.

RESULTS

Four RCTs were included for analysis, with a total of 1510 patients (743 controls and 767 ICG patients). The rate of AL was 9% in the ICG group (69/767) and 13.9% (103/743) in the control group (p = 0.003, RR -0.5, 95% CI -0.827 to -0.172, heterogeneity test 0%, p = 0.460). The RD in terms of incidence of AL was significantly decreased by 4.51% (p = 0.031, 95% CI -0.086 to -0.004, heterogeneity test 28%, p = 0.182) when using ICG.

CONCLUSION

Our meta-analysis suggested that use of ICG during rectal cancer surgery could reduce the rate of AL.

Best Evidence for Each Surgical Step in Minimally Invasive Right Hemicolectomy: A Systematic Review

Objective

The aim of this study was to systematically review the literature for each surgical step of the minimally invasive right hemicolectomy (MIRH) for non-locally advanced colon cancer, to define the most optimal procedure with the highest level of evidence.

Background

High variability exists in the way MIRH is performed between surgeons and hospitals, which could affect patients' postoperative and oncological outcomes.

Methods

A systematic search using PubMed was performed to first identify systematic reviews and meta-analyses, and if there were none then landmark papers and consensus statements were systematically searched for each key step of MIRH. Systematic reviews were assessed using the AMSTAR-2 tool, and selection was based on highest quality followed by year of publication.

Results

Low (less than 12 mmHg) intra-abdominal pressure (IAP) gives higher mean quality of recovery compared to standard IAP. Complete mesocolic excision (CME) is associated with lowest recurrence and highest 5-year overall survival rates, without worsening short-term outcomes. Routine D3 versus D2 lymphadenectomy showed higher LN yield, but more vascular injuries, and no difference in overall and disease-free survival. Intracorporeal anastomosis is associated with better intra- and postoperative outcomes. The Pfannenstiel incision gives the lowest chance of incisional hernias compared to all other extraction sites.

Conclusion

According to the best available evidence, the most optimal MIRH for colon cancer without clinically involved D3 nodes entails at least low IAP, CME with D2 lymphadenectomy, an intracorporeal anastomosis and specimen extraction through a Pfannenstiel incision.

Progress of near-infrared-II fluorescence in precision diagnosis and treatment of colorectal cancer

Colorectal cancer is a malignant tumour with high incidence and mortality worldwide; therefore, improving the early diagnosis of colorectal cancer and implementing a targeted "individualized treatment" strategy is of great concern. NIR-II fluorescence imaging is a large-depth, high-resolution optical bioimaging tool. Around the NIR-II window, researchers have developed a variety of luminescent probes, imaging systems, and treatment methods with colorectal cancer targeting capabilities, which can be visualized and image-guided in clinical surgery. This article aims to overcome the difficulties in diagnosing and treating colorectal cancer. The present review summarizes the latest results on using NIR-II fluorescence for targeted colorectal cancer imaging, expounds on the application prospects of NIR-II optical imaging for colorectal cancer, and discusses the imaging-guided multifunctional diagnosis and treatment platforms.

Is ICG essential in all colorectal surgery? A 3-year experience in a single center: a cohort study

INTRODUCTION AND OBJECTIVES

Indocyanine green (ICG) was introduced as a promising diagnostic tool to provide real-time assessment of intestinal vascularization. Nevertheless, it remains unclear whether ICG could reduce the rate of postoperative AL. The objective of this study is to assess its usefulness and to determine in which patients is most useful and would benefit the most from the use of ICG for intraoperative assessment of colon perfusion.

METHODS

A retrospective cohort study was conducted in a single center, including all patients who underwent colorectal surgery with intestinal anastomosis between January 2017 and December 2020. The results of patients in whom ICG was used prior to bowel transection were compared with the results of the patients in whom this technique was not used. Propensity score matching (PSM) was employed to compare groups with and without ICG.

RESULTS

A total of 785 patients who underwent colorectal surgery were included. The operations performed were right colectomies (35.0%), left colectomies (48.3%), and rectal resections (16.7%). ICG was used in 280 patients. The mean time since the infusion of ICG until detection of fluorescence in the colon wall was 26.9 ± 1.2 s. The section line was modified in 4 cases (1.4%) after ICG due to a lack of perfusion in the chosen section line. Globally, a non-statistically significant increase in anastomotic leak rate was observed in the group without ICG (9.3% vs. 7.5%; p = 0.38). The result of the PSM was a coefficient of 0.026 (CI - 0.014 to 0.065, p = 0.207).

CONCLUSIONS

ICG is a safe and useful tool to assess the perfusion of the colon prior to performing the anastomosis in colorectal surgery. However, in our experience, it did not significantly lower the anastomotic leakage rate.

Long-term Oncological Results After Laparoscopic Sigmoidectomy for Adenocarcinoma

Purpose: Sigmoidectomy is performed in most cases for benign pathologies and mainly in cases of diverticulitis. Few studies in the literature report oncological results after sigmoidectomy for adenocarcinoma. The aim of this study was to report the long-term oncological outcomes after elective laparoscopic sigmoidectomy (LS) for adenocarcinoma. Methods: This study is a retrospective analysis of prospectively collected data. From January 2003 to February 2021, 173 patients underwent elective LS for adenocarcinoma. Twenty-four patients with a diagnosis of preoperative distant metastases were excluded (13.9%). Results: Seven postoperative complications were observed (7.1%). Of these, 2 (2%) anastomotic leakages were treated surgically by the Hartmann procedure (Clavien-Dindo grade III-b). The mean number of harvested lymph nodes with the specimen was 14.2 ± 7.1. At a median follow-up of 115 months (interquartile range 133.8), 2 (2%) and 9 patients (9.2%) had developed recurrence and metastases, respectively. During follow-up, 6 patients (6.1%) with metastases died due to disease progression and 6 other patients (6.1%) died due to causes other than cancer related. At the 5- and 10-year follow-ups, the overall survival rates were 90.5% ± 3.4% and 83.8% ± 4.5%, respectively, while the disease-free survival rates were 87.1% ± 4.1% and 83.5% ± 4.7%, respectively. Conclusion: LS is a safe and feasible technique both in terms of the number of harvested lymph nodes and oncological results. The possibility of sparing the colon without mobilizing the splenic flexure and dividing the left colic artery could reduce intra- and postoperative complications. Further studies with larger samples of patients are required to confirm these data.

Cost analysis of indocyanine green fluorescence angiography for prevention of anastomotic leakage in colorectal surgery

BACKGROUND

Indocyanine green, near infrared, fluorescence angiography (ICG-FA) is increasingly adopted in colorectal surgery for intraoperative tissue perfusion assessment to reduce anastomotic leakage rates. However, the economic impact of this intervention has not been investigated. This study is a cost analysis of the routine use of ICG-FA in colorectal surgery from the hospital payer perspective.

METHODS

A decision analysis model was developed for colorectal resections considering two scenarios: resection without using ICG-FA and resection with intraoperative ICG-FA for anastomotic perfusion assessment. Incorporated into the model were the costs of ICG agent, fluorescence angiography equipment, surgery, anastomotic leak, and the leak rates with and without ICG-FA. All input data were derived from recent publications.

RESULTS

The routine use of ICG-FA for colorectal anastomosis is cost saving when cost analysis is performed using the following base case assumptions: 8.6% leak rate without ICG-FA, odds ratio of 0.46 for reduction of leakage with ICG-FA (4.8% leak rate relative to 8.6% base case), cost of ICG-FA of $250, and incremental cost of leak, not requiring reoperation, of $9,934.50. In one-way sensitivity analyses, routine use of ICG-FA was cost saving if the cost of an anastomotic leak is more than $5616.29, the cost of ICG-FA is less than $634.44, the leak rate (without ICG-FA) is higher than 4.9%, or the odds ratio for reduction of leak with ICG-FA is less than 0.69. There is a per-case saving of $192.22 with the use of ICG-FA.

CONCLUSION

Using the best available evidence and most conservative base case values, routine use of ICG-FA in colorectal surgery was found to be cost saving. Since the evidence suggests there is a reduction in leak rate, the routine use of ICG-FA is a dominating strategy. However, the overall quality of evidence is low and there is a clear need for prospective, randomized controlled trials.

Complications after bowel resection for inflammatory bowel disease associated cancer: a systematic literature review

INTRODUCTION

Inflammatory bowel disease (IBD) associated colorectal cancer represents the 1-2% of all patients affected by colorectal carcinoma, but it is frequent responsible for death in these patients. Aim of this systematic review was to report the complications after bowel resection in patients with IBD associated cancer.

EVIDENCE ACQUISITION

A systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. The search was carried out in PubMed, Embase, Cochrane and Web of Science databases. A total of 54,084 articles were found. Of these 38,954 were eliminated because were duplicates between the searches. Of the remaining 15,130 articles, 14,888 were excluded after screening title and abstract.

EVIDENCE SYNTHESIS

Two-hundred-forty-two articles were fully analyzed, and 239 further articles were excluded. Finally, three articles were included for a total of 63 patients. Overall, 38 early postoperative complications (60.3%) were observed. Of these, anastomotic leakage occurred in 13 patients (20.6%). The indication for surgery was ulcerative colitis in 52 patients (82.5%), Crohn's disease in 8 patients (12.7%) and indeterminate colitis in 3 patients (4.8%). Intraoperative complications, readmission and postoperative mortality were not observed.

CONCLUSIONS

Complication rate after bowel resection for IBD associated cancer is not different from complication rate after colorectal surgery for other diseases. Given the high probability of developing a cancer and the time correlated occurrence of malignancy in IBD patients, it should be debated if a surgical resection should be performed as soon as dysplasia is detected in IBD patients or earlier in their life.

The Role of Indocyanine Near-Infrared Fluorescence in Colorectal Surgery

PURPOSES

The aim of this study was to evaluate the importance of Indocyanine Green in control of anastomosis perfusion and on anastomotic leakage rates during laparoscopic and robotic colorectal procedures.

METHODS

A retrospective review of patients who underwent elective minimally invasive surgery for colorectal cancer from 1 January 2018 to 31 December 2020 was performed. All patients underwent Near-Infrared Fluorescence-Indocyanine Green system in two moments: before performing the anastomosis and after completing the anastomotic procedure. Primary outcomes were the rate of intraoperative change in the surgical resection due to an inadequate vascularization and the rate of postoperative anastomotic leakage. Secondary outcomes were the postoperative complications, both medical and surgical (intra-abdominal bleeding, anastomotic leakage).

RESULTS

Our analysis included 93 patients. Visible fluorescence was detected in 100% of the cases. In 7 patients (7.5%), the planned site of resection was changed due to inadequate perfusion. The mean extension of the surgical resection in these 7 patients was 2.2 ± 0.62. Anastomotic leakage occurred in 2 patients (2.1%). Other complications included 8 postoperative bleedings (8.6%) and 1 pulmonary thromboembolism.

CONCLUSIONS

The intraoperative use of Near-Infrared Fluorescence-Indocyanine Green in colorectal surgery is safe, feasible, and associated with a substantial reduction in postoperative anastomotic leakage rate.

Combined indocyanine green and quantitative perfusion assessment with hyperspectral imaging during colorectal resections

Anastomotic insufficiencies still represent one of the most severe complications in colorectal surgery. Since tissue perfusion highly affects anastomotic healing, its objective assessment is an unmet clinical need. Indocyanine green-based fluorescence angiography (ICG-FA) and hyperspectral imaging (HSI) have received great interest in recent years but surgeons have to decide between both techniques. For the first time, two data processing pipelines capable of reconstructing an ICG-FA correlating signal from hyperspectral data were developed. Results were technically evaluated and compared to ground truth data obtained during colorectal resections. In 87% of 46 data sets, the reconstructed images resembled the ground truth data. The combined applicability of ICG-FA and HSI within one imaging system might provide supportive and complementary information about tissue vascularization, shorten surgery time, and reduce perioperative mortality.

Feasibility of quantitative analysis of colonic perfusion using indocyanine green to prevent anastomotic leak in colorectal surgery

BACKGROUND

The aim of this study was to quantify Fluorescence angiography with indocyanine green (ICG) in colorectal cancer anastomosis, determine influential factors in its temporary intensity and pattern, assessing the ability to predict the AL, and setting the cut-off levels to establish high- or low-risk groups.

METHODS

Retrospective analysis of prospectively managed database, including 70 patients who underwent elective surgery for colorectal cancer in which performing a primary anastomosis was in primary plan. In all of them, ICG fluorescence angiography was performed as usual clinical practice with VisionSense™ VS Iridium (Medtronic, Mansfield, MA, USA), in Elevision™ IR Platform (Medtronic, Mansfield, MA, USA). Parameters measured at real time or calculated were T₀, T_max, ∆T, F_max, %_pos, F_pos, and Slope.

RESULTS

70 patients were included, 69 anastomosis were performed and one end colostomy. Arterial hypertension demonstrated higher F_max, as well as the location of the anastomosis (the nearest to rectum, the most intensity detected). A statistical relationship was found between AL and the lower F_pos and Slope. The decision of changing the subjectively decided point of division did not demonstrate statistical difference on the further development of AL. All parameters were analyzed to detect the cut-off related with AL. Only in case of F_pos lower than 158.3 U and Slope lower than 13.1 U/s p-value were significant. The most valuable diagnostic parameter after risk stratification was the Negative Predictive Value.

CONCLUSION

Quantitative analysis of ICG fluorescence in colorectal surgery is safe and feasible to stratify risk of AL. Hypertension and location of anastomosis influence the intensity of fluorescence at the point of section. A change of division place should be considered to avoid AL related to vascular reasons when intensities of fluorescence at the point of section is lower than 169 U or slopes lower than 14.4 U/s.

Fluorescent imaging for cancer therapy and cancer gene therapy

The translation of laboratory science into effective clinical cancer therapy is gaining momentum more rapidly than any other time in history. Understanding cancer cell-surface receptors, cancer cell growth, and cancer metabolic pathways has led to many promising molecular-targeted therapies and cancer gene therapies. These same targets may also be exploited for optical imaging of cancer. Theoretically, any antibody or small molecule targeting cancer can be labeled with bioluminescent or fluorescent agents. In the laboratory setting, fluorescence imaging (FI) and bioluminescence imaging (BLI) have long been used in preclinical research for quantification of tumor bulk, assessment of targeting of tumors by experimental agents, and discrimination between primary and secondary effects of cancer treatments. Many of these laboratory techniques are now moving to clinical trials. Imageable engineered fluorescent probes that are highly specific for cancer are being advanced. This will allow for the identification of tumors for staging, tracking novel therapeutic agents, assisting in adequate surgical resection, and allowing image-guided biopsies. The critical components of FI include (1) a fluorescent protein that is biologically safe, stable, and distinctly visible with a high target to background ratio and (2) highly sensitive optical detectors. This review will summarize the most promising optical imaging agents and detection devices for cancer clinical research and clinical care.

Clinical effect and standardization of indocyanine green angiography in the laparoscopic colorectal surgery

Anastomotic complications occur after 5% to 20% of operations for rectosigmoid colon cancer. The intestinal perfusion status at the anastomotic site is an important modifiable risk factor, and surgeons should carefully evaluate and optimize the perfusion at the intended site of anastomosis. Indocyanine green (ICG) angiography is a simple noninvasive perfusion assessment modality. The use of ICG angiography is rapidly spreading in the field of colorectal surgery. However, there is debate on its contribution to reducing anastomotic complications. In this review, we discuss the clinical utility and the standardization of ICG angiography. ICG angiography can unequivocally reveal unfavorable perfusion zones and provide quantitative parameters to predict the risk of hypoperfusion-related anastomotic complications. Many studies have demonstrated the clinical utility of ICG angiography for reducing anastomotic complications. Recently, two multicenter randomized clinical trials reported that ICG angiography did not significantly reduce the incidence of anastomotic leakage. Most previous studies have been small-scale single-center studies, and there is no standardized ICG angiography protocol to date. Additionally, ICG angiography evaluations have mostly relied on surgeons’ subjective judgment. For these reasons, it is necessary to establish a standardized ICG angiography protocol and develop a quantitative analysis protocol for the objective assessment. In conclusion, ICG angiography could be useful for detecting poorly perfused colorectal segments to prevent anastomotic leakage after colorectal surgery. An optimized and standardized ICG angiography protocol should be established to improve the reliability of perfusion assessments. In the future, artificial intelligence-based quantitative analyses could be used to easily assess colonic perfusion status.

Effect of indocyanine green fluorescence angiography on preventing anastomotic leakage after colorectal surgery: a meta-analysis

Anastomotic leakage (AL) is a serious but not uncommon complication after colorectal surgery. We conducted this study to evaluate the effect of routine indocyanine green fluorescence angiography (ICG-FA) on reducing the AL rate after colorectal surgery. We identified all research articles about colorectal surgery using ICG-FA, published in the PubMed, EMBASE, and Cochrane Library databases from the date of database establishment to May 2020. Revman 5.3 was used for statistical analysis. We analyzed 22 controlled studies and 7 non-controlled studies on ICG-FA, including 6312 patients. The controlled studies included 2354 patients in the ICG group and 3522 patients in the non-ICG group. Meta-analysis showed that ICG-FA reduced the AL rate after colorectal surgery significantly (RR = 0.39; 95% CI 0.30-0.50; P < 0.00001). However, patients whose resection line was changed based on the fluorescence angiography had a higher AL rate than those whose resection line was not changed (OR = 5.37; 95% CI 2.67-10.81; P < 0.00001). The overall complication rate, severe complication rate, and reoperation rate in the ICG group were significantly lower than those in the non-ICG group (RR = 0.79, 95% CI 0.67-0.92, P = 0.002; RR = 0.67, 95% CI 0.47-0.96, P = 0.03; RR = 0.53, 95% CI 0.29-0.96, P = 0.04, respectively), whereas the postoperative ileus rate was significantly higher in the ICG group than in the non-ICG group (RR = 1.65; 95% CI 1.09-2.50; P = 0.02), especially in Western countries (RR = 1.6; 95% CI 1.04-2.47; P = 0.03).ICG-FA may reduce the AL rate after colorectal surgery, but ICG-FA group patients with transection line change for insufficient blood perfusion to the anastomotic stoma after evaluation had a higher AL rate than those without transection line change. Therefore, ICG-FA can help to identify patients at high risk of AL and intercept its occurrence. Moreover, ICG-FA may reduce the overall complication rate, severe complication rate, and reoperation rate, but induce postoperative ileus. High-quality randomized-controlled trials with a placebo control are needed to further evaluate the effectiveness and safety of ICG-FA.

Management of postoperative complications after laparoscopic left hemicolectomy: an approach in modern times after incorporation of indocyanine green and full mobilization of the splenic flexure

BACKGROUND

The aim of this study was to report our experience in the management of complications after laparoscopic left hemicolectomy (LLH) after the incorporation in our clinical practice of intraoperative indocyanine green (ICG) fluorescence angiography (FA).

METHODS

In our last period after incorporation of ICG-FA, 277 unselected consecutive patients underwent laparoscopic colorectal surgery with this technology. Ninety-seven (35%) right hemicolectomy, 19 segmental resection of the splenic flexure (6.9%), 54 anterior resection of the rectum (19.5%) and 107 LLH (38.6%) were performed. Complications were graded according to Clavien-Dindo classification, and anastomotic leakages (AL) were graded according to Clavien-Dindo classification and to International Study Group of Rectal Cancer (ISGRC) classification.

RESULTS

Eight surgical and one medical complications (8.4%) were observed. Two AL occurred (1.9%). One drained spontaneously by drainage placed intraoperatively (Clavien-Dindo I, ISGRC A) and one treated by laparoscopic peritoneal lavage, leakage suture and ileostomy (Clavien-Dindo III-b, ISGRC C). Other complications were: wound infection (Clavien-Dindo II) (2); postoperative anemia caused by rectorrhagia (Clavien-Dindo II) (2); pelvic abscess between bladder and uterus (Clavien-Dindo III-a) (1); hemoperitoneum secondary to inferior mesenteric artery bleeding treated with peritoneal lavage and hemostasis (Clavien-Dindo III-b) (1); atrial fibrillation (Clavien-Dindo II) (1). All complications have been resolved.

CONCLUSIONS

The complication rate after LLH after the incorporation of ICG-FA is low, since the number of AL have dramatically decreased in comparison to our previous experience. The management of these patients proved to be safe and effective due to in all cases the complication has been resolved. Further studies are required to standardize the management of these patients.

Indocyanine Green Fluorescence in Colorectal Cancer

Fluorescence vision using indocyanine green is a surgical tool with increasing applications in colorectal cancer surgery. This tool has received acceptance in several disciplines as a potential method to improve visualization of the surgical field, improve lymph node resection and decrease the incidence of anastomotic leaks (ALs). In colorectal surgery specifically, some studies have shown that intraoperative fluorescence imaging is a safe and feasible method to evaluate anastomotic perfusion, and its use could affect the incidence of anastomotic leaks. Currently, controlled trials are carried out to validate these conclusions, as well as new indications for indocyanine green such as detection and guidance in the management of hepatic colorectal metastases, visualization of ureters and even as tumor marking and improvement the lymph node harvest of early tumors. These advances could offer great value to surgeons and patients, by improving the accuracy and results of cancer resections.

Optimization of indocyanine green angiography for colon perfusion during laparoscopic colorectal surgery

AIM

This study aims to evaluate the extrinsic effects of conditional factors affecting quantitative parameters and to establish the optimization of indocyanine green (ICG) angiography using in vitro experiments and a prospective observational study.

METHOD

In vitro experiments were performed to evaluate the correlation between conditional factors such as camera distance, surrounding lighting, fluorescence emission sources and ICG doses. The fluorescence intensity was measured from the ICG-containing test tube in each condition. In the clinical study, ICG angiography was applied to patients with colorectal cancer (n = 164). The quantitative perfusion parameters were the maximal fluorescence intensity (F_MAX ), slope, T_1/2MAX and perfusion time ratio (TR). Camera position, distance to colon, fluorescence emission source, surrounding lighting, site of angiography and ICG specific mode were considered as conditional factors and compared with the quantitative parameters to identify the optimal condition of ICG angiography.

RESULTS

The fluorescence intensity had an inverse correlation with distance, and the transitional zone was shown at a distance of 4-5 cm by slope differential. F_MAX , T_1/2MAX and slope were affected significantly by camera distance, site of angiography, fluorescence emission source and ICG mode as conditional factors. On multivariate analysis, F_MAX was independently associated with spectral ICG mode with red inversion, laser mode and camera distance. Conversely, TR was not related to any conditional factors.

CONCLUSION

Since quantitative parameters of ICG angiography are influenced by various conditions, a standardized protocol is required. The application of ICG specific modes with a constant distance of 4-5 cm can provide optimized fluorescence images.

Multifunctional Indocyanine Green Applications for Fluorescence-Guided Laparoscopic Colorectal Surgery

Indocyanine green (ICG) could be applied for multiple functions such as fluorescent tumor localization, fluorescence lymph node mapping (FLNM), and intraoperative angiography in colorectal cancer surgery. With the near-infrared (NIR) systems, colonoscopic ICG tattooing can be used to define the early colorectal cancer that cannot be easily distinguished through the serosal surface. The lymphatic pathways can be visualized under the NIR system when ICG is injected through the submucosal or subserosal layer around the tumor. Intraoperative ICG angiography can be applied to find a favorable perfusion segment before the colon transection. Although all fluorescence functions are considered essential steps in image-guided surgery, it is difficult to perform multifunctional ICG applications in a single surgical procedure at once because complex protocols could interfere with each other. Therefore, we review the multifunctional ICG applications for fluorescent tumor localization, FLNM, and ICG angiography. We also discuss the optimal protocol for fluorescence-guided colorectal surgery.

INDOCYANINE GREEN FLUORESCENCE IMAGING IN ROBOTIC SURGERY: STATE OF ART, TIPS AND TRICKS IN CURRENT APPLICATIONS

BACKGROUND

Fluorescent imaging with indocyanine green is an emerging technology whose benefits are put in perspective.

OBJECTIVE

This article reports essential principles and approaches of intraoperative fluorescence in general surgery bringing familiarity to its practical usage. Our group describes possible pitfalls and provides tips and tricks for training surgeons making their attempts easier and reproducible during practice.

METHODS

This study overviews the most structured concepts, practical applications and its tricks in robotic fluorescence guided imaging surgery with indocyanine green. Possible pitfalls are emphasized and emerging fields of application are put in a perspective.

RESULTS

Guided information and practical applications in several surgical fields are described for a safe and reproducible indocyanine green fluorescence imaging use.

CONCLUSION

Robotic assisted surgery combined to fluorescence imaging technology represents a logical evolution in image guided surgery and technology familiarity with guided information may represent a wider and safer spectrum of use in surgeons' hands.

Extended Left Colectomy with Coloanal Anastomosis by Indocyanine Green-guided Deloyers Procedure: A Case Report

The Deloyers procedure is performed after extended left colectomy, enabling the reach of the proximal colon to the rectum for anastomosis while preserving sufficient blood supply. We report a case of the Deloyers procedure performed safely under indocyanine green (ICG) fluorescence guidance. A 50-year-old man with obesity (body mass index, 35.7 kg/m²) and a history of diabetes underwent an extended left hemicolectomy and ultralow anterior resection of the rectum as radical resection for transverse and sigmoid colon cancers and a lower rectal neuroendocrine tumor. Reconstruction was performed by the Deloyers procedure. A necessary length of the transverse colon with reduced blood flow was additionally resected under ICG fluorescence guidance, and a transanal hand-sewn coloanal anastomosis was performed. This is the first report in which the Deloyers procedure was performed successfully with the ICG fluorescence method. ICG fluorescence may be useful when combined with the Deloyers procedure.

Maltohexaose-indocyanine green (MH-ICG) for near infrared imaging of endocarditis

Infectious endocarditis is a life-threatening disease, and diagnostics are urgently needed to accurately diagnose this disease especially in the case of prosthetic valve endocarditis. We show here that maltohexaose conjugated to indocyanine green (MH-ICG) can detect Staphylococcus aureus (S. aureus) infection in a rat model of infective endocarditis. The affinity of MH-ICG to S. aureus was determined and had a Km and Vmax of 5.4 μM and 3.0 X 10⁻⁶ μmol/minutes/10⁸ CFU, respectively. MH-ICG had no detectable toxicity to mammalian cells at concentrations as high as 100 μM. The in vivo efficiency of MH-ICG in rats was evaluated using a right heart endocarditis model, and the accumulation of MH-ICG in the bacterial vegetations was 2.5 ± 0.2 times higher than that in the control left ventricular wall. The biological half-life of MH-ICG in healthy rats was 14.0 ± 1.3 minutes, and approximately 50% of injected MH-ICG was excreted into the feces after 24 hours. These data demonstrate that MH-ICG was internalized by bacteria with high specificity and that MH-ICG specifically accumulated in bacterial vegetations in a rat model of endocarditis. These results demonstrate the potential efficacy of this agent in the detection of infective endocarditis.

Intra-operative assessment of left-sided colorectal anastomotic integrity: a systematic review of available techniques

AIM

Anastomotic leak (AL) after colorectal resection is associated with increased rates of morbidity and mortality: potential permanent stoma formation, increased local recurrence, reduced cancer-related survival, poor functional outcomes and associated quality of life. Techniques to reduce leak rates are therefore highly sought.

METHOD

A literature search was performed for published full text articles using PubMed, Cochrane and Scopus databases with a focus on colorectal surgery 1990-2020. Additional papers were detected by scanning references of relevant papers.

RESULTS

A total of 53 papers were included after a thorough literature search. Techniques assessed included leak tests, endoscopy, perfusion assessment and fluorescence studies. Air-leak testing remains the most commonly used method across Europe, due to ease of reproducibility and low cost. There is no evidence that this reduces the leak rate; however, identification of a leak intra-operatively provides the opportunity for either suture reinforcement or formal takedown with or without re-do of the anastomosis and consideration of diversion. Suture repair alone of a positive air-leak test is associated with an increased AL rate. The use of fluorescence studies to guide the site of anastomosis has demonstrated reduced leak rates in distal anastomoses, is safe, feasible and has a promising future.

CONCLUSION

Although over reliance on any assessment tool should be avoided, intra-operative techniques with the aim of reducing AL rates are increasingly being employed. Standardization of these methods is imperative for routine use. However, in the interim it is recommended that all anastomoses should be assessed intra-operatively for mechanical failure, particularly distal anastomoses.

Intraoperative perfusion assessment of the proximal colon by a visual grading system for safe anastomosis after resection in left-sided colorectal cancer patients

We aimed to evaluate the clinical feasibility of a new visual grading system. We included 50 patients who underwent resection of primary colorectal cancer. Before anastomosis, the marginal vessel was cut and the perfusion status was assessed by a visual grading system. The visual grading system is comprised of five grades according to the bleeding from the marginal vessel and is categorized into 4 groups: good (grade A and B), moderate (grade C), poor (grade D) and none (grade E). Colorectal anastomosis was performed only in the good and moderate groups. We compared postoperative outcomes between the good and moderate groups and analysed the factors affecting the perfusion grade. Among the patients, 48% were grade A, 12% were grade B, and 40% were grade C. There was no anastomotic leakage. Only one patient with grade C showed ischemic colitis and needed reoperation. Age was the only factor correlated with perfusion grade in multivariate analysis (OR 1.080, 95% CI 1.006-1.159, p = 0.034). The perfusion grades were significantly different between > 65 and < 65 year-old patients (> 65, A 29.2% B 12.5% C 58.3% vs. < 65, A 65.4% B 11.5% C 23.1%, p = 0.006). Our intraoperative perfusion assessment that uses a cutting method and a visual grading system is simple and useful for performing a safe anastomosis after colorectal resection. If the perfusion grade is better than grade C, an anastomosis can be performed safely. Age was found to be an important factor affecting the perfusion grade.

[Evidence of indocyanine green fluorescence in robotically assisted colorectal surgery : What is the status?]

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is increasingly being used in various areas of abdominal surgery. The constant improvement in the technology enables easy intraoperative use and progressively influences operative decision-making, also in robotically assisted colorectal surgery.

OBJECTIVE

Summation of current evidence on the use of ICG fluorescence imaging in robotically assisted colorectal surgery.

MATERIAL AND METHODS

The assessment of evidence is based on a comprehensive literature search (PubMed).

RESULTS

First individual studies (feasibility, case matched, prospective cohort, multicenter phase II, single center randomized controlled study/trial) showed a significant reduction in the incidence of anastomotic leakage (AL) after colorectal anastomosis through the use of ICG fluorescence angiography (FA, 9.1% vs. 16.3%; p = 0.04). First feasibility studies demonstrated lymph node detection or navigation as well as ureter visualization.

CONCLUSION

The ICG-FA reliably detects tissue perfusion, quickly and effectively with few side effects. It can influence intraoperative decision-making and reduce AL rates. In addition, patients may be offered more precise tumor therapy via ICG sentinel lymph node (SLN) detection and lateral pelvic lymph node (LPN) mapping and navigation. Iatrogenic lesions, such as ureteral injuries can be sufficiently prevented by appropriate visualization; however, valid data in order to be able to derive standardized operative consequences require further convincing multicenter, randomized controlled trials (mRCT).

Clinical impact of leakage in patients with handsewn vs stapled anastomosis after right hemicolectomy: a retrospective study

AIM

Anastomotic leakage is a major complication after right hemicolectomy leading to increased morbidity, mortality, length of stay and hospital costs. Previous studies have shown that the type of anastomosis (handsewn or stapled) is a major risk factor for anastomotic leakage. The purpose of this study was to evaluate the clinical impact of anastomotic leakage depending on the type of anastomotic technique (handsewn vs stapled).

METHOD

This was an observational, retrospective, cross-sectional study. Data were collected at two major hospitals in Spain from January 2010 to December 2016. Patients had elective right colectomy for cancer with handsewn or stapled ileocolic anastomosis. The main outcome was the grading of postoperative treatments needed to manage anastomotic leakage according to two major classification systems. The other outcomes were demographics, time of hospitalization and death rate.

RESULTS

Patients (n = 961) underwent elective surgery for neoplasia of the right colon. Anastomotic leakage was diagnosed in 116 patients (12.07%). Patients with handsewn anastomosis had more Type IIIA surgical complications and received milder treatments than patients with stapled anastomosis (SA) who had more Type IIIB complications and more re-laparotomies (P = 0.004). The clinical impact of anastomotic leakage was significantly more severe (Grade C) in patients with SA than in patients with a handsewn anastomosis (P = 0.007). No differences were found for hospital stay of patients with anastomotic leakage depending on the type of anastomosis (P = 0.275). Death due to anastomotic leakage was similar in both groups.

CONCLUSIONS

The clinical impact of anastomotic leakage in patients with handsewn anastomosis is lower than in patients with SA.

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.

Ultimate Stomaless Technique of Two-Stage Operation for Lower Rectal Cancer Performed on a Patient with a High Body Mass Index: The Reborn Operation (Novel Pull-Through Method)

A 58-year-old Japanese man, with a body mass index of 41.7 kg/m² (height: 179.8 cm; weight: 133.8 kg), underwent a laparoscopic pull-through procedure with delayed coloanal anastomosis performed in two surgical stages for lower rectal cancer. This method was selected because the volume of the abdominal wall was fairly thick and it would have been impossible to perform diverting ileostomy and colostomy, which are routinely conducted. First, a colonic pull-through segment of about 10 cm was left outside the anal canal without any tension and was fixed by sutures under indocyanine green fluorescence imaging (ICG FI). The second surgical stage was performed 10 days after the first operation under general anesthesia. Final coloanal anastomosis was performed with near-infrared light without diverting the stoma under ICG FI. The patient demonstrated a good postoperative course and was discharged from our hospital in remission 15 days after the latest operation. We could inspect the coloanal flow of the anastomosis under ICG FI before the reconstruction. This procedure was considered to be a standard method, but it was overtaken by new technology, ICG FI. This procedure is an ultimate stomaless surgery for ultralow rectal cancer that can be performed in selected cases, such as in patients with a high body mass index and with hope for stomaless operation.