Author: fidelmac

Background and Objectives: Retrograde free venous flaps represent a separate entity among free venous flaps: their physiology is still unclear, but they provide an immediate visible refill after reconnection, with a similar behaviour to conventional flaps. Therefore, the dimensions and the indications of these flaps can be extended beyond what was previously believed, and they can be easily customized, including with respect to tendons and nerves. Nevertheless, they are still debated and regarded as unsafe.

Materials and Methods: From 2012 to 2019, we performed 31 retrograde free venous flaps on 31 patients to reconstruct hands, digits, and in one case the heel. All the flaps were arterialized in a retrograde manner; the donor site was the forearm in 28 cases, the foot in 2 cases, and the calf in 1 case. We recorded the size, vein architecture, donor site, donor artery, donor morbidity, function for composite and non-composite flaps, immediate complications, late complications, survival rate, and the number of revisions. We recorded the hand function when appropriate. A total of 10 flaps were also intraoperatively studied with indocyanine green to monitor their hemodynamical behaviour.

Results: All the patients were followed for an average of 8 months (6-15). The flap dimensions ranged from 6 cm2 to 136 cm2. All the flaps, except two that had complete necrosis, survived. Two flaps had partial necrosis. There was no correlation between necrosis and the size of the flap, with one case of necrosis and one of partial necrosis in the small flaps (<10 cm2). None of the cases with partial necrosis needed a new flap. Two flaps developed a late arterio-venous shunt that was ligated.

Conclusions: The retrograde free venous flaps proved to be a useful tool for complex reconstructions of the hand and extremities. They can provide a large island of pliable skin and composite tissue with tendons and nerves, but surgeons must be aware of some caveats.

https://pubmed.ncbi.nlm.nih.gov/36013532/

Background: Fluorescence imaging using indocyanine green in thoracic and esophageal surgery is gaining popularity because of the potential to facilitate surgical planning, disease staging, and reduce postoperative complications. To optimize use of fluorescence imaging in thoracic and esophagealsurgery, an expert panel sought to establish a set of recommendations at a consensus meeting.

Methods: The panel included 12 experts in thoracic and/or upper gastrointestinal surgery from Asia Pacific countries. Prior to meeting, seven focus areas were defined: i) intersegmental plane identification for sublobar resections ii) pulmonary nodule localization; iii) lung tumor detection; iv) bullous lesion detection; v) lymphatic mapping of lung tumors; vi) evaluation of gastric conduit perfusion; and vii) lymphatic mapping in esophageal surgery. A literature search of the PubMed database was conducted using keywords ‘indocyanine green’, ‘fluorescence’, ‘thoracic’, ‘surgery’ and ‘esophagectomy’. At the meeting, panelists addressed each focus area by discussing the most relevant evidence and their clinical experiences. Consensus statements were derived from the proceedings, followed by further discussions, revisions, finalization and unanimous agreement. Each statement was assigned a level of evidence and a grade of recommendation.

Results: A total of nine consensus recommendations were established. Identification of the intersegmental plane for sublobar resections, localization of pulmonary nodules, lymphatic mapping in lung tumors, and assessment of gastric conduit perfusion were applications of fluorescence imaging that have the most robust current evidence.

Conclusions: Based on best available evidence and expert opinions, these consensus recommendations may facilitate thoracic and esophageal surgery using fluorescence imaging.

https://pubmed.ncbi.nlm.nih.gov/36030832/

Background: There is insufficient evidence on whether indocyanine green (ICG) fluorescence angiography can reduce the incidence of anastomotic leakage (AL). This retrospective cohort study aimed to evaluate the effect of ICG fluorescence angiography on AL rates in laparoscopic rectal cancer surgery at a single institution.

Methods: Patients who underwent laparoscopic low anterior resection or intersphincteric resection with ICG fluorescence angiography (ICG group; n=73) and patients who underwent a similar surgical procedure for rectal cancer without ICG fluorescence (non-ICG group; n=114) were enrolled consecutively in this study. ICG fluorescence angiography was performed prior to transection of the proximal colon, and anastomosis was performed with sufficient perfusion using ICG fluorescence imaging. AL incidence was compared between both groups, and the risk factors for AL were analyzed.

Results: AL occurred in 3 (4.1%) and 14 (12.3%) patients in the ICG and non-ICG groups, respectively. In the ICG group, the median perfusion time from ICG injection was 34 s, and 5 patients (6.8%) required revision of the proximal transection line. None of the patients requiring revision of the proximal transection line developed AL. In the univariate analysis, longer operating time (odds ratio: 2.758; 95% confidence interval: 1.023–7.624) and no implementation of ICG fluorescence angiography (odds ratio: 3.266; 95% confidence interval: 1.038–11.793) were significant factors associated with AL incidence, although the creation of a diverting stoma or insertion of a transanal tube was insignificant.

Conclusion: ICG fluorescence angiography was associated with a significant reduction in AL during laparoscopic rectal cancer surgery. Changes in the surgical plan due to ICG fluorescence visibility may help improve the short-term outcomes of patients with rectal cancer.

https://www.researchsquare.com/article/rs-1943148/v1

Adequate surgical margins following gastrectomy for gastric cancer are required. In addition, a method for accurately detecting tumor location without palpation is needed during robotic surgery. Although several methods have been reported, most of these either lack accuracy or require increased time and effort during intraoperative detection. Herein, we introduce a new method for detecting tumor location using preoperative indocyanine green (ICG) marking and the built-in ICG detection system of the da Vinci Xi Surgical System in robotic gastrectomy to determine appropriate surgical margins.

We used this method to determine the resection line in six patients who underwent robotic distal gastrectomy for clinical T1 gastric cancer. One to three days before surgery, ICG was diluted to 1.0 mg/mL, and 0.1 mL of this diluted ICG solution was endoscopically injected at one site into the submucosal layer of the stomach, 1 cm proximal to the tumor edge. Gastrectomy was performed using the da Vinci Xi surgical platform, equipped with a near-infrared fluorescence imaging system (Firefly®). The diameter of the fluorescent signal during gastrectomy was estimated to be approximately 2 cm.

The resection line was determined on the outer edge of the fluorescent signal, which ensured a tumor-free margin of ≥2 cm. Fluorescent signals were successfully observed in all cases. Moreover, the required 2-cm surgical margin was achieved in all cases. We could successfully determine proximal margins using preoperative ICG injection marking during robotic distal gastrectomy for gastric cancer.

https://onlinelibrary.wiley.com/doi/abs/10.1111/ases.13121

Objective: To assess the feasibility and effectiveness of indocyanine green (ICG) for image-guided resection of head and neck cancer (HNC).

Review methods: Searches were conducted from database inception to February 2022. Patient and study characteristics, imaging parameters, and imaging efficacy data were extracted from each study.

Results: Nine studies met inclusion criteria, representing 103 head and neck tumors. Weighted mean ICG dose and imaging time were 1.27 mg/kg and 11.77 h, respectively. Among the five studies that provided quantitative metrics of imaging  efficacy, average ICG tumor-to-background ratio (TBR) was 1.56 and weighted mean ONM-100 TBR was 3.64. Pooled sensitivity and specificity across the five studies were 91.7 % and 71.9 %, respectively.

Conclusion: FGS with ICG may facilitate real-time tumor-margin delineation to improve margin clearance rates and progression-free survival. Future studies with validated, quantitative metrics of imaging success are necessary to further evaluate the prognostic benefit of these techniques.

https://pubmed.ncbi.nlm.nih.gov/35939987/

Check out the recently launched Dutch fluorescence guided surgery group website and announcement of their first symposium in September 16^th

https://dfgs-group.org/

Background: Indocyanine green (ICG) is commonly used to assess perfusion, but quality defining features are lacking. We sought to establish qualitative features of esophageal ICG perfusion assessments, and develop an esophageal anastomotic scorecard to risk-stratify anastomotic outcomes.

Methods: Single institution, retrospective analysis of children with an intraoperative ICG perfusion assessment of an esophageal anastomosis. Qualitative perfusion features were defined and a perfusion score developed. Associations between perfusion and clinical features with poor anastomotic outcomes (PAO, leak or refractory stricture) were evaluated with logistic and time-to-event analyses. Combining significant features, we developed and tested an esophageal anastomotic scorecard to stratify PAO risk.

Results: From 2019 to 2021, 53 children (median age 7.4 months) underwent 55 esophageal anastomoses. Median (IQR) follow-up was 14 (10-19.9) months; mean (SD) perfusion score was 13.2 (3.4). Fifteen (27.3%) anastomoses experienced a PAO and had significantly lower mean perfusion scores (11.3 (3.3) vs 14.0 (3.2), p = 0.007). Unique ICG perfusion features, severe tension, and primary or rescue traction-induced esophageal lengthening [Foker] procedures were significantly associated with PAO on both logistic and Cox regression. The scorecard (range 0-7) included any Foker (+2), severe tension (+1), no arborization on either segment (+1), suture line hypoperfusion >twice expected width (+2), and segmental or global areas of hypoperfusion (+1). A scorecard cut-off >3 yielded a sensitivity of 73% and specificity of 93% (AUC 0.878 [95%CI 0.777 to 0.978]) in identifying a PAO.

Conclusions: A scoring system comprised of qualitative ICG perfusion features, tissue quality, and anastomotic tension can help risk-stratify esophageal anastomotic outcomes accurately.

https://pubmed.ncbi.nlm.nih.gov/35934523/

Objective: To compare the (sentinel) lymph node detection rate of ICG-fluorescent imaging versus standard-of-care 99mTc-nanocoilloid for sentinel lymph node (SLN)-mapping.

Summary background data: The current gold-standard for axillary staging in patients with breast cancer is sentinel lymph node biopsy (SLNB) using radio-guided surgery with radioisotope technetium (99mTc), sometimes combined with blue dye. A promising alternative is fluorescent imaging using indocyanine green (ICG).

Methods: In this non-inferiority trial, we enrolled 102 consecutive patients with invasive early-stage, clinically node-negative breast cancer. Patients were planned for breast conserving surgery and SLNB between August 2020 and June 2021. The day or morning before surgery, patients were injected with 99mTc-nanocolloid. In each patient, SLNB was first performed using ICG-fluorescent imaging, after which excised lymph nodes were tested with the gamma-probe for 99mTc-uptake ex-vivo, and the axilla was checked for residual 99mTc-activity. Detection rate was defined as the proportion of patients in whom at least one (S)LN was detected with either tracer.

Results: In total, 103 SLNBs were analysed. The detection rate of ICG-fluorescence was 96.1% (95%CI=90.4-98.9%) versus 86.4% (95%CI=78.3-92.4%) for 99mTc-nanocoilloid. The detection rate for pathological lymph nodes was 86.7% (95%CI=59.5-98.3%) for both ICG and 99mTc-nanocoilloid. A median of 2 lymph nodes were removed. ICG-fluorescent imaging did not increase detection time. No adverse events were observed.

Conclusion: ICG-fluorescence showed a higher (S)LN detection rate than 99mTc-nanocoilloid, and equal detection rate for pathological (S)LNs. ICG-fluorescence may be used as a safe and effective alternative to 99mTc-nanocoilloid for SLNB in patients with early-stage breast cancer.

https://pubmed.ncbi.nlm.nih.gov/35894448/

Researchers nowadays have devoted extra attention to the different biomedical applications of indocyanine green (ICG), a US Food and Drug Administration (FDA)-approved fluorescent compound in the fields such as drug delivery, medical imaging, and disease diagnosis. In addition, hepatic function evaluation could be conducted by using ICG before surgical procedures and angiographic assessment of blood. Therefore, ICG will be expected to be excellent imaging and targeting agent in various preclinical and clinical model systems.

However, whether ICG possesses the potential for the gall bladder’s intraoperative imaging guidance needs to be further explored in vivo animal experiments. Herein, NIR fluorophores ICG can display the specific uptake by the gall bladder cells and tissues. The dynamic process of biodistribution and the clearance of ICG in vivo in mice are clearly shown in real-time live-body imaging.

Furthermore, ICG was rapidly excreted into the bile and lately biodistributed to the stomach after treatment in mice. Meanwhile, the signal-to-background ratio (SBR) of the gall bladder demonstrated a tremendously higher level compared to other organs (stomach, heart, liver, lung, pancreas, spleen, intestine, and duodenum).

In conclusion, fluorescence navigation using ICG fluorescence imaging will provide good visualization and detection of the target lesions (gall bladder) in clinics such as diagnostic medical imaging and intraoperative navigation.

https://pubmed.ncbi.nlm.nih.gov/35904773/