Use of indocyanine green fluorescence imaging to determine the area of bowel resection in non-occlusive mesenteric ischemia: A case report

Intraoperative indocyanine green fluorescence for precise resection of nonocclusive mesenteric ischemia: a case report and diagnostic considerations based on pathology findings

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI) is characterized by intestinal ischemia caused by spasms in the peripheral intestinal vessels without organic obstruction in the main mesenteric vessels. NOMI can be fatal in case of delayed diagnosis and treatment. Although the use of indocyanine green (ICG) fluorescence in assessing intestinal viability during NOMI surgery is well recognized, there is a paucity of reported cases using this technique. Herein, we present a case of NOMI that was successfully managed through accurate diagnosis and resection of the ischemic intestines guided by ICG fluorescence.

CASE PRESENTATION

An 81-year-old man presented with abdominal pain. Contrast-enhanced computed tomography revealed intrahepatic portal vein gas, superior mesenteric vein gas, and terminal ileal edema. Considering these findings, the patient was diagnosed with NOMI and emergency surgery was performed. Intestinal edema was observed 30 cm upstream of the terminal ileum without serosal discoloration. ICG fluorescence revealed areas of normal perfusion as well as mild and moderate hypoperfusion. The small bowel, including the hypoperfusion area, was resected. As no clinical signs of residual bowel ischemia were observed during the postoperative course, a second-look operation was deemed unnecessary. Intraoperative ICG fluorescence and histopathological findings indicated mucosal edema in the mildly hypoperfused area and mucosal necrosis in the moderately hypoperfused area.

CONCLUSIONS

This case highlights the use of intraoperative ICG fluorescence in the disease. ICG fluorescence is invaluable in assessing the extent of bowel ischemia and guiding precise resection. Thus, future efforts should focus on identifying accumulation of cases and quantification of ICG fluorescence intensity to further improve diagnostic performance.

A Green Lantern for the Surgeon: A Review on the Use of Indocyanine Green (ICG) in Minimally Invasive Surgery

Indocyanine green (ICG) fluorescence imaging has revolutionized surgical practice across various medical and surgical specialties. This article reviews the clinical applications of ICG in abdominal, urological, thoracic, and gynecological surgery. ICG fluorescence imaging has been widely adopted in general surgery for various applications, including perfusion assessment, intraoperative visualization of the ureter, and tumor localization. It is particularly valuable in evaluating anastomotic leaks and aiding in precise tumor resection during minimally invasive surgeries. Studies have shown mixed results on its effectiveness in reducing anastomotic leak rates, highlighting the need for further research. In thoracic surgery, ICG facilitates the identification and resection of pulmonary bullae, as well as the precise localization of pulmonary nodules during video-assisted surgery. In urology, ICG aids in localizing renal tumors and guiding selective arterial occlusion during partial nephrectomy. Its role in identifying the lymphatic pathway in prostate cancer and sentinel lymph node biopsy in gynecological cancer is also discussed. Despite its benefits, the use of ICG fluorescence faces challenges such as limited tissue penetration, the potential for false results, a lack of standardized protocols, and high equipment costs. Nonetheless, it remains a powerful tool that could improve surgical outcomes.

Cesena guidelines: WSES consensus statement on laparoscopic-first approach to general surgery emergencies and abdominal trauma

BACKGROUND

Laparoscopy is widely adopted across nearly all surgical subspecialties in the elective setting. Initially finding indication in minor abdominal emergencies, it has gradually become the standard approach in the majority of elective general surgery procedures. Despite many technological advances and increasing acceptance, the laparoscopic approach remains underutilized in emergency general surgery and in abdominal trauma. Emergency laparotomy continues to carry a high morbidity and mortality. In recent years, there has been a growing interest from emergency and trauma surgeons in adopting minimally invasive surgery approaches in the acute surgical setting. The present position paper, supported by the World Society of Emergency Surgery (WSES), aims to provide a review of the literature to reach a consensus on the indications and benefits of a laparoscopic-first approach in patients requiring emergency abdominal surgery for general surgery emergencies or abdominal trauma.

METHODS

This position paper was developed according to the WSES methodology. A steering committee performed the literature review and drafted the position paper. An international panel of 54 experts then critically revised the manuscript and discussed it in detail, to develop a consensus on a position statement.

RESULTS

A total of 323 studies (systematic review and meta-analysis, randomized clinical trial, retrospective comparative cohort studies, case series) have been selected from an initial pool of 7409 studies. Evidence demonstrates several benefits of the laparoscopic approach in stable patients undergoing emergency abdominal surgery for general surgical emergencies or abdominal trauma. The selection of a stable patient seems to be of paramount importance for a safe adoption of a laparoscopic approach. In hemodynamically stable patients, the laparoscopic approach was found to be safe, feasible and effective as a therapeutic tool or helpful to identify further management steps and needs, resulting in improved outcomes, regardless of conversion. Appropriate patient selection, surgeon experience and rigorous minimally invasive surgical training, remain crucial factors to increase the adoption of laparoscopy in emergency general surgery and abdominal trauma.

CONCLUSIONS

The WSES expert panel suggests laparoscopy as the first approach for stable patients undergoing emergency abdominal surgery for general surgery emergencies and abdominal trauma.

ICG-augmented hyperspectral imaging for visualization of intestinal perfusion compared to conventional ICG fluorescence imaging: an experimental study

BACKGROUND

Small bowel malperfusion (SBM) can cause high morbidity and severe surgical consequences. However, there is no standardized objective measuring tool for the quantification of SBM. Indocyanine green (ICG) imaging can be used for visualization, but lacks standardization and objectivity. Hyperspectral imaging (HSI) as a newly emerging technology in medicine might present advantages over conventional ICG fluorescence or in combination with it.

METHODS

HSI baseline data from physiological small bowel, avascular small bowel and small bowel after intravenous application of ICG was recorded in a total number of 54 in-vivo pig models. Visualizations of avascular small bowel after mesotomy were compared between HSI only (1), ICG-augmented HSI (IA-HSI) (2), clinical evaluation through the eyes of the surgeon (3) and conventional ICG imaging (4). The primary research focus was the localization of resection borders as suggested by each of the four methods. Distances between these borders were measured and histological samples were obtained from the regions in between in order to quantify necrotic changes 6 h after mesotomy for every region.

RESULTS

StO2 images (1) were capable of visualizing areas of physiological perfusion and areas of clearly impaired perfusion. However, exact borders where physiological perfusion started to decrease could not be clearly identified. Instead, IA-HSI (2) suggested a sharp-resection line where StO2 values started to decrease. Clinical evaluation (3) suggested a resection line 23 mm (±7 mm) and conventional ICG imaging (4) even suggested a resection line 53 mm (±13 mm) closer towards the malperfused region. Histopathological evaluation of the region that was sufficiently perfused only according to conventional ICG (R3) already revealed a significant increase in pre-necrotic changes in 27% (±9%) of surface area. Therefore, conventional ICG seems less sensitive than IA-HSI with regards to detection of insufficient tissue perfusion.

CONCLUSIONS

In this experimental animal study, IA-HSI (2) was superior for the visualization of segmental SBM compared to conventional HSI imaging (1), clinical evaluation (3) or conventional ICG imaging (4) regarding histopathological safety. ICG application caused visual artifacts in the StO2 values of the HSI camera as values significantly increase. This is caused by optical properties of systemic ICG and does not resemble a true increase in oxygenation levels. However, this empirical finding can be used to visualize segmental SBM utilizing ICG as contrast agent in an approach for IA-HSI. Clinical applicability and relevance will have to be explored in clinical trials.

LEVEL OF EVIDENCE

Not applicable. Translational animal science. Original article.

Application of fluorescence-guided surgery in the acute care setting: a systematic literature review

PURPOSE

Fluorescence-based imaging has found application in several fields of elective surgery, but there is still a lack of evidence in the literature about its use in emergency setting. The present review critically summarizes currently available applications and limitations of indocyanine green (ICG) fluorescence in abdominal emergencies including acute cholecystitis, mesenteric ischemia, and trauma surgery.

METHODS

A systematic review was performed according to the PRISMA statement identifying articles about the use of ICG fluorescence in the management of the most common general surgery emergency. Only studies focusing on the use of ICG fluorescence for the management of acute surgical conditions in adults were included.

RESULTS

Thirty-six articles were considered for qualitative analysis. The most frequent disease was occlusive or non-occlusive mesenteric ischemia followed by acute cholecystitis. Benefits from using ICG for acute cholecystitis were reported in 48% of cases (clear identification of biliary structures and a safer surgical procedure). In one hundred and twenty cases that concerned the use of ICG for occlusive or non-occlusive mesenteric ischemia, ICG injection led to a modification of the surgical decision in 44 patients (36.6%). Three studies evaluated the use of ICG in trauma patients to assess the viability of bowel or parenchymatous organs in abdominal trauma, to evaluate the perfusion-related tissue impairment in extremity or craniofacial trauma, and to reassess the efficacy of surgical procedures performed in terms of vascularization. ICG injection led to a modification of the surgical decision in 50 patients (23.9%).

CONCLUSION

ICG fluorescence is a safe and feasible tool also in an emergency setting. There is increasing evidence that the use of ICG fluorescence during abdominal surgery could facilitate intra-operative decision-making and improve patient outcomes, even in the field of emergency surgery.

Time limit to rescue intestine with viability at risk caused by blood flow disruption in patients presenting with acute abdomen

Purpose

Early management is crucial for acute intestinal blood flow disorders; however, no published study has identified criteria for the time limit for blood flow resumption. This study specifically examines the time factors for avoiding intestinal resection.

Methods

The subjects of this retrospective cohort study were 125 consecutive patients who underwent emergency surgery for a confirmed diagnosis of intestinal strangulation (n = 86), incarceration (n = 27), or volvulus (n = 12), between January 2015 and March 2021. Intestinal resection was performed when intestinal irreversible changes had occurred even after ischemia was relieved surgically. We analyzed the relationship between the time from computed tomography (CT) imaging to the start of surgery (C-S time) and intestinal resection using the Kaplan–Meier method and calculated the estimated intestinal rescue rate. Patient background factors affecting intestinal resection were also examined.

Results

The time limit for achieving 80% intestinal rescue rate was 200 min in C-S time, and when this exceeded 300 min, the intestinal rescue rate dropped to less than 50%. Multivariate analysis identified the APACHE II score as a significant influencing factor.

Conclusion

A rapid transition from early diagnosis to early surgery is critical for patients with acute abdomen originating from intestinal blood flow disorders. The times from presentation at the hospital to surgery should be reduced further, especially for severe cases.

Utility of X-ray and indocyanine green fluorescence imaging in detecting hepatocellular carcinoma dissemination on laparoscopic surgery: A case report

Indocyanine green (ICG) fluorescence imaging is useful for the intraoperative detection of the peritoneal dissemination of hepatocellular carcinoma (HCC). However, in laparoscopic surgery, disseminations cannot be accurately identified unless the camera lens is positioned close to the lesion. The present study describes a case of HCC dissemination in which the lesions were accurately identified by combining intraoperative fluoroscopy with ICG fluorescence imaging. A 76-year-old male was diagnosed with HCC dissemination. Computed tomography revealed a 9-mm disseminated nodule near the gallbladder. Although transarterial chemoembolization had also been used to treat this lesion, chemoembolization was technically difficult to perform. Therefore, a coil was placed around the lesion to serve as an intraoperative landmark for later laparoscopic resection. Given the potential difficulty of detecting the lesion during laparoscopic surgery, ICG fluorescence imaging was used to determine the approximate location of the dissemination. The lesion exhibited strong fluorescence, which facilitated its complete resection.

Rapid intraoperative perfusion assessment of parathyroid adenomas with ICG using a wide-field portable hand-held fluorescence imaging system

BACKGROUND

Fluorescence angiography (FA) using indocyanine green dye (ICG) has recently been introduced for real-time identification of parathyroid adenomas. However, time to peak fluorescence has not yet been critically evaluated.

METHODS

This was a retrospective review of parathyroidectomies with ICG FA over a one-year period.

RESULTS

There were 66 patients with average age of 64 years. The average time to initial fluorescence was 26.7 s and to peak fluorescence was 38.0 s. The time to saline flush administration significantly correlated with times to initial and peak fluorescence (p < .0001). The rate of in-situ fluorescence was 97%. The rates of suspected adenoma detection were 69% for sestamibi scan, 71% for ultrasound, and 96% for CT scan. Imaging was discordant in 13 cases (20%), with the adenoma located on the opposite side of the neck in 4 cases.

CONCLUSIONS

ICG FA is a rapid and effective adjunct for the intraoperative identification of parathyroid adenomas.

Nonocclusive mesenteric ischemia associated with postoperative jejunal tube feeding: Indicators for clinical management

Postoperative nutrition via a jejunal tube after major abdominal surgery is usually well tolerated. However, some patients develop nonocclusive mesenteric ischemia (NOMI). This morbid complication has a grave prognosis with a mortality rate of 41% to 100%. Early symptoms are nonspecific, and no treatment guideline is available. We reviewed cases of NOMI at our institution and cases described in the literature to identify factors that impact the clinical course. Among five patients, three had no necrosis and one had segmental necrosis and perforation. These patients recovered with limited resection and decompression of the bowel and abdominal compartment. In one patient with extended bowel necrosis at the time of re-laparotomy, NOMI progressed and the patient died of multiple organ failure. The extent of small bowel necrosis at the time of re-laparotomy is a relevant prognostic factor. Therefore, early diagnosis and treatment of NOMI can improve the prognosis. Clinical symptoms of abdominal distension, cramps and high reflux plus paraclinical signs of leukocytosis, hypotension and computed tomography findings of a distended small bowel with pneumatosis intestinalis and portal venous gas can help to establish the diagnosis. We herein introduce an algorithm for the diagnosis and management of NOMI associated with jejunal tube feeding.

A Systematic Review of the Utility of Indocyanine Angiography in Autologous Breast Reconstruction

BACKGROUND

In the last decade, a number of studies have demonstrated the utility of indocyanine green (ICG) angiography in predicting mastectomy skin flap necrosis for immediate breast reconstruction. However, data are limited to investigate this technique for autologous breast reconstruction. Although it may have the potential to improve free flap outcomes, there has not been a large multicenter study to date that specifically addresses this application.

METHODS

A thorough literature review based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines was conducted. All studies that examined the use of intraoperative ICG angiography or SPY to assess perfusion of abdominally based free flaps for breast reconstruction from January 1, 2000, to January 1, 2020, were included. Free flap postoperative complications including total flap loss, partial flap loss, and fat necrosis were extracted from selected studies.

RESULTS

Nine relevant articles were identified, which included 355 patients and 824 free flaps. A total of 472 free flaps underwent clinical assessment of perfusion intraoperatively, whereas 352 free flaps were assessed with ICG angiography. Follow-up was from 3 months to 1 year. The use of ICG angiography was associated with a statistically significant decrease in flap fat necrosis in the follow-up period (odds ratio = 0.31, P = 0.02). There was no statistically significant difference for total or partial flap loss.

CONCLUSIONS

From this systematic review, it can be concluded that ICG angiography may be an effective and efficient way to reduce fat necrosis in free flap breast reconstruction and may be a more sensitive predictor of flap perfusion than clinical assessment alone. Future prospective studies are required to further determine whether ICG angiography may be superior to clinical assessment in predicting free flap outcomes.

Hyperspectral imaging and indocyanine green fluorescence angiography in acute mesenteric ischemia: A case report on how to visualize intestinal perfusion

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First case of HSI and ICG in Acute mesenteric ischemia.

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Similar results of moth modalities with regard to well perfused intestine.

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ICG shows exact vascular blood supply and intestinal perfusion.

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Hyperspectral imaging can distinguish necrotic and vital intestinal segments in AMI.

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Combined use helps surgeons to evaluate intestinal perfusion intraoperatively in AMI.

Introduction and importance

Acute mesenteric ischemia is a challenging acute condition which is often caused by occlusion of an intestinal vessel. Therapeutic algorithms include revascularization of the occluded vessel and a surgical procedure to remove necrotic intestine. Sometimes necrotic intestine is hard to identify visually. Therefore, tools such as hyperspectral imaging (HSI) and indocyanine green fluorescence angiography (ICGFA) might be helpful for objective intraoperative evaluation of intestinal perfusion.

Case presentation

We present a case of an 80-year-old woman with an acute superior mesenteric artery occlusion and subsequent intestinal gangrene. After endovascular arterial revascularization, we performed an explorative laparotomy in which we assessed intestinal perfusion by HSI and ICGFA. Both HSI and ICGFA showed a sharp perfusion borderline in the proximal jejunum. The distal intestine showed low tissue oxygenation (HSI) and inhomogeneous perfusion (ICGFA).

Clinical discussion

Both methods showed reproducible results for tissue perfusion and, thus, could provide additional information on the extent of necrotic bowel with need for resection. Therefore, both modalities might be used in future image-guided surgery in cases of acute mesenteric ischemia where visual discrimination of intestinal perfusion is challenging in order to resect as much bowel as necessary to improve patient outcome. Both methods exert different strengths: i.e. ICGFA is real-time angiography, whereas HSI may expose intestinal necrosis in spectroscopy.

Conclusion

We show, for the first time, simultaneous imaging of HSI and ICGFA in a case of acute mesenteric ischemia. Both imaging modalities reveal similar results reliably concerning intestinal perfusion.

Fluorescence-Based Quantification of Gastrointestinal Perfusion: A Step Towards an Automated Approach

Background: Qualitative fluorescence angiography (FA) provides insights into intestinal tissue perfusion, but today it is not yet accurate in predicting anastomotic leakage. To improve peroperative detection of impaired perfusion, quantified parameters should be investigated using a standardized method. The aim of this study was to develop a (semi)automated algorithm for comprehensive and convenient analysis of FA parameters. Materials and Methods: An analysis tool was developed for the extraction of quantified FA parameters. The start- and endpoint of intensity increase (T₀ and Tmax) were automatically detected in the intensity-time curves. Algorithm performance was measured against manual assignment of T₀ and Tmax by 9 independent observers in 18 in vivo generated test signals, using the intraclass correlation coefficient (ICC). Characteristics of parameter T1∕2 (time to 50% of maximal intensity) were analyzed in normally perfused small intestine of 32 subjects who underwent robotic laparoscopic surgery. Since ethical approval was not required under the Dutch law, the need for informed consent was waived. Results: Automated detection of T₀ and Tmax was successful in all subjects. Output of the algorithm had an excellent agreement with the median of the human observations: ICC = 0.95 (95% confidence interval: 0.86-0.96). Overall, T1∕2 had a median value of 5.1 (interquartile range = 2.4) seconds and a minimal and maximal value of 1.3 and 9.9 seconds, respectively. Conclusions: The presented method provided convenient data analysis in the search for effective FA quantification. Future research should expand the data to find adequate threshold values for peroperatively identifying insufficient perfusion and investigate the influence of physiological conditions.

Planned Versus On-Demand Relaparotomy Strategy in Initial Surgery for Non-occlusive Mesenteric Ischemia

BACKGROUND

There has been insufficient evidence regarding a treatment strategy for patients with non-occlusive mesenteric ischemia (NOMI) due to the lack of large-scale studies. We aimed to evaluate the clinical benefit of strategic planned relaparotomy in patients with NOMI using detailed perioperative information.

METHODS

We conducted a multicenter retrospective cohort study that included NOMI patients who underwent laparotomy. In-hospital mortality, 28-day mortality, incidence of total adverse events, ventilator-free days, and intensive care unit (ICU)-free days were compared between groups experiencing the planned and on-demand relaparotomy strategies. Analyses were performed using a multivariate mixed effects model and a propensity score matching model after adjusting for pre-operative, intra-operative, and hospital-related confounders.

RESULTS

A total of 181 patients from 17 hospitals were included, of whom 107 (59.1%) were treated using the planned relaparotomy strategy. The multivariate mixed effects regression model indicated no significant differences for in-hospital mortality (61 patients [57.0%] in the planned relaparotomy group vs. 28 patients [37.8%] in the on-demand relaparotomy group; adjusted odds ratio [95% confidence interval] = 1.94 [0.78-4.80]), as well as in 28-day mortality, adverse events, and ICU-free days. Significant reduction in ventilator-free days was observed in the planned relaparotomy group. Propensity score matching analysis of 61 matched pairs with comparable patient severity did not show superiority of the planned relaparotomy strategy.

CONCLUSIONS

The planned relaparotomy strategy, compared with on-demand relaparotomy strategy, did not show clinical benefits after the initial surgery of patients with NOMI. Further studies estimating potential subpopulations who may benefit from this strategy are required.

Techniques for intraoperative evaluation of bowel viability in mesenteric ischemia: A review

Acute mesenteric ischemia (AMI) is a deadly and common surgical emergency. While several imaging modalities aid in the diagnosis of AMI preoperatively, there are limited intraoperative tools for surgeon decision making regarding bowel viability. Here we offer a review of the utility and limitations of the many extensively studied techniques. We classify each of these modalities into three hallmarks of healthy bowel: oxygenation, myoelectric activity and perfusion. Finally, we offer a brief discussion of emerging and promising techniques to assist surgeons in intraoperative decision making for patients with mesenteric ischemia.