Laser-Assisted Indocyanine Green Dye Angiography for Postoperative Fistulas After Salvage Laryngectomy

Larynx Cancer: Reconstructive Options

Reconstruction for laryngeal cancer will depend on the defect left by surgical resection and patient-related factors such as medical comorbidities and history of previous radiation treatment. The goals of reconstruction are to preserve and/or restore the primary functions of the larynx (breathing, swallowing, voicing). Options include primary closure, locoregional flaps, and microvascular free tissue each with their advantages and disadvantages, which should be considered when planning reconstruction.

Adherence to the Dietary Approaches to Stop Hypertension (DASH) Eating Pattern Reduces the Risk of Head and Neck Cancer in American Adults Aged 55 Years and Above: A Prospective Cohort Study

OBJECTIVES

Dietary Approaches to Stop Hypertension (DASH) pattern has been found to aid in the reduction of obesity, oxidative stress, and chronic inflammation, which are all strongly linked to the development of head and neck cancer (HNC). Nevertheless, no epidemiological studies have investigated the association between this dietary pattern and HNC risk. This study was conducted with the purpose of bridging this gap in knowledge.

DESIGN

A prospective cohort study involving 98,459 American adults aged 55 years and older.

SETTING AND PARTICIPANTS

Data were drawn from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Trial. In the present study, participants with dependable energy intake data who furnished baseline and dietary history information were identified as the study population.

METHODS

Diet was assessed by food frequency questionnaires and the DASH score was calculated to assess each participant's adherence to DASH eating pattern. Cox proportional hazards models were used to calculate multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the occurrence of HNC. To visualize the variation in cancer risk for HNC and its subtypes across the entire spectrum of DASH scores, restricted cubic spline plots were utilized. Additionally, a series of predefined subgroup analyses were performed to identify potential effect modifiers, and several sensitivity analyses were conducted to assess the stability of the findings.

RESULTS

During a follow-up period of 871,879.6 person-years, 268 cases of HNC were identified, comprising 161 cases pertaining to oral cavity and pharynx cancers, as well as 96 cases of larynx cancer. In the fully adjusted model, adherence to the DASH diet was associated with a remarkable 57% reduction in the risk of HNC when comparing extreme quartiles (HR quartile 4 vs 1: 0.43; 95% CI: 0.28, 0.66; P for trend < 0.001). The restricted cubic spline plots demonstrated a linear dose-response relationship between the DASH score and the risk of HNC as well as its subtypes. Subgroup analysis revealed that the protective effect of the DASH diet against HNC was particularly pronounced in individuals with lower daily energy intake. The primary association remained robust in the sensitivity analysis.

CONCLUSIONS

In American middle-aged and older population, adherence to the DASH diet may help prevent HNC, particularly for individuals with lower daily energy intake.

Applications of intraoperative angiography in head and neck reconstruction

Objective

Laser-assisted angiography with indocyanine green (LAIG) allows objective intraoperative evaluation of tissue vascularity. We endeavored to describe our experience with this technique in the head and neck region.

Methods

A retrospective review from February 2016 till October 2018 was conducted. We included patients who underwent head and neck procedures in which LAIG was employed. The main outcome was postoperative wound complications. We analysed the influence of LAIG results in intraoperative decision-making process.

Results

Nineteen patients were included, and follow-up was for at least 6 months. LAIG was employed in 11 local flaps, 9 free flaps and 6 cases of pharyngeal closure during total laryngectomies. Wound complications occurred in two cases with distal tip flap necrosis. LAIG findings resulted in changes in decision making intraoperatively in 84% of procedures, which consisted in trimming poorly perfused tissues. There were no pharyngocutaneous fistulas.

Conclusions

This represents a descriptive report on the use of LAIG on diverse head and neck reconstruction cases, with important impact on the decision-making process. A low number of postoperative wound complications were observed.

The Use of Indocyanine Green Angiography for Cosmetic and Reconstructive Assessment in the Head and Neck

Reconstructive procedures in the head and neck can be a surgical challenge owing to the complex anatomical and physiological structure. Different locoregional and microvascular flaps are used for various defects to improve both function and cosmesis. Subjective clinical findings have been the mainstay for perfusion monitoring; however, areas of borderline perfusion are much more difficult to assess clinically. Multiple technologies that offer objective perfusion assessment have been developed to improve surgical outcomes. Indocyanine green (ICG) angiography has gained popularity owing to its minimal invasiveness and increased sensitivity and specificity in assessing flap perfusion particularly in the head and neck. It has been extensively used in free flaps, pedicled flaps (including nasal reconstruction), facelift procedures, random flaps, skull base reconstruction, and pharyngocutaneous fistula prediction. Its perioperative use has provided valuable qualitative and quantitative data that aid our understanding of flap hemodynamics. Clinically, this impacted decision-making in flap design, harvest, inset, and precocious salvage interventions. Though increased cost and intraoperative time could be limitations, cost-effectiveness studies have supported its use, particularly in high-risk individuals. Limitations include the lack of standardized dosing and consistent methodology agreement for data analysis. Future studies should involve larger cohorts and multi-institute studies to overcome such limitations.

Intraoperative Dye Test in Total Laryngectomy: A Technique to Reduce the Incidence of Pharyngocutaneous Fistula

Background:

Pharyngocutaneous fistula (PCF) could complicate laryngectomy in advanced disease. The cause is multifactorial, and this may include poor technique in pharyngeal repair. Intraoperative assessment of the repaired mucosa integrity for adequate closure may reduce PCF, but this is not routinely done.

Objective:

The objective of this study is to describe a novel technique that has been successfully used to ascertain intraoperative pharyngeal repair integrity.

Methods:

Thirty-one patients who had total laryngectomy and pharyngeal reconstruction for locally advanced laryngeal squamous cell carcinoma were studied. Connell extramucosal suturing technique was used for the mucosal repair. Thereafter, a small feeding tube was introduced through the oral cavity to the site of the pharyngeal repair, and diluted methylene-blue dye was injected through it while digitally occluding the cervical esophagus. Whenever leakage of the dye was seen, the leakage site (s) was repaired. Thereafter, the dye test would be repeated to confirm the integrity of the repair.

Results:

Their mean age was 53.4 ± 10.9 years. Seven (22.6%) patients had Stage 3 disease and 24 (77.4%) had Stage 4 disease. All the patients had neck dissection, whereas 3 (9.7%) patients had salvage laryngectomy postradiotherapy. Dye test was performed intraoperatively for all the patients and leakages were seen in 4 (12.9%) patients which were successfully repaired. Oral feeding was commenced on the fifth postoperative day, and none of the patients had PCF.

Conclusion:

Performing a dye test intraoperatively helps detect the point of leakage and immediate repair will prevent PCF.

Utility of Indocyanine Green Angiography to Identify Clinical Factors Associated With Perfusion of Paramedian Forehead Flaps During Nasal Reconstruction Surgery

Importance

Identifying factors affecting forehead flap neovascularization during nasal reconstruction surgical procedures using quantitative dynamics of fluorescence from indocyanine green angiography may be associated with reduced vascular complications.

Objectives

To identify quantifiable forehead flap perfusion measures using indocyanine green angiography during nasal reconstruction procedures and to evaluate clinical factors associated with neovascularization.

Design, Setting, and Participants

Retrospective cohort study of 71 patients at a tertiary referral center of Stanford University, Stanford, California, between January 1, 2010, and March 31, 2018, undergoing forehead flap nasal reconstruction surgery with flap perfusion assessed by indocyanine green angiography.

Exposures

Indocyanine green angiography was performed intraoperatively to record forehead flap neovascularization during the second stage of nasal reconstruction surgery after temporary clamping of the pedicle.

Main Outcomes and Measures

With use of quantifiable data of fluorescence dynamics, flap perfusion in association with a reference point in the cheek after pedicle clamping was assessed by 2 methods: (1) ingress (arterial inflow) and egress (venous outflow) flap-to-cheek ratio and (2) flap-to-cheek perfusion (fluorescence) ratio at 3 time points (midpoint of indocyanine green flap inflow, maximum fluorescence [peak], and midpoint of indocyanine green flap outflow) and their calculated mean. Association of the perfusion measures with patient and procedural factors was performed using linear regression models.

Results

Of the 71 patients included in the study, 43 (61%) were men; the mean (SD) age was 71.1 (11.0) years. The mean (SD) flap-to-cheek inflow ratio was 0.48 (0.40), peak fluorescence ratio was 0.59 (0.34), and outflow ratio was 0.88 (0.42). The calculated mean (SD) flap-to-cheek perfusion ratio of these measures was 0.65 (0.35). The mean (SD) flap-to-cheek ingress ratio was 0.54 (0.36) and egress ratio was 0.65 (0.98). With use of a multivariable regression model, the time between stages was positively associated with flap-to-cheek ingress ratio (β, 0.015; 95% CI, 0.001 to 0.030), and cartilage grafting was negatively associated with flap-to-cheek outflow ratio (β, -0.240; 95% CI, -0.472 to -0.008).

Conclusions and Relevance

The findings suggest that indocyanine green angiography is an effective method to quantify relative neovascularization perfusion of forehead flaps. Future applications may include the use of this technology to aid in early flap division and ensure adequate perfusion among high-risk patients.

Level of Evidence

NA.

Intraoperative Fluorescent Angiography Predicts Pharyngocutaneous Fistula After Salvage Laryngectomy

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Fallopian tube perfusion in ex-vivo and in-vivo laparoscopic hysterectomy specimens: potential application for uterine transplantation

STUDY QUESTION

Is there perfusion to the fallopian tubes in ex-vivo and in-vivo uteri at the time of total laparoscopic hysterectomy (TLH), as observed using laser angiography with indocyanine green (ICG)?

SUMMARY ANSWER

The fallopian tubes may have perfusion from the utero-ovarian vasculature alone.

WHAT IS KNOWN ALREADY

The fallopian tubes are perfused by the uterine and utero-ovarian vessels. Perfusion can be measured using laser angiography with ICG.

STUDY DESIGN, SIZE, DURATION

This prospective pilot cohort study included 15 women, ages 32-59 years old, who underwent TLH with bilateral salpingectomy for benign indications.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In five participants, TLH was performed and the utero-ovarian artery was cannulated ex vivo and injected with ICG. The other 10 participants underwent the in-vivo protocol. The mesosalpinx and uterine vessels were transected in the partial protocol. Colpotomy was also performed in the complete protocol. All fallopian tubes were imaged using laser angiography with ICG. The relative fluorescence and the fluorescence intensity ratio (length of fluorescent fallopian tube/total length of fallopian tube) of the fallopian tubes were measured in the ex-vivo and in-vivo protocols, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

Ex vivo, the fimbria of the ipsilateral fallopian tube had 47% median relative fluorescence as compared to the contralateral fallopian tube, which had 2.4% median relative fluorescence. In vivo, the post-ICG fluorescence intensity ratios were 0.61 ± 0.40 for the partial protocol, and 0.78 ± 0.30 for the complete protocol, with mean differences of 0.37 (95% CI: 0.23-0.50, P < .0001) and 0.22 (95% CI: 0.12-0.31, P < 0.0001), respectively, between the pre-procedure and the post-ICG fluorescence intensity ratios. Greater than 0.75 fluorescence intensity ratios (i.e. >75% tubal length fluorescence) was seen in 60% of fallopian tubes.

LIMITATIONS, REASONS FOR CAUTION

This is a pilot study with a small sample size and pathologic uteri, which would not be appropriate for uterine transplantation. No conclusions can be made regarding the functionality of the fallopian tubes.

WIDER IMPLICATIONS OF THE FINDINGS

The fallopian tubes may have perfusion with the utero-ovarian vasculature alone, potentially allowing for future animal studies regarding tubal viability in recipients of uterine-tubal transplants. If successful, human uterine-tubal transplantation may allow for spontaneous conception rather than IVF.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used. S.F., P.F.P., K.A.S. and R.F. have no conflicts of interest to report. M.L.S. is an educational consultant for Medtronic (Dublin, Republic of Ireland) and Applied Medical (Rancho Santa Margarita, CA, USA), as well as a stockholder for SynDaver Labs (Tampa, FL, USA). S.E.Z. is an educational consultant for Applied Medical (Rancho Santa Margarita, CA, USA) and is on the advisory board for AbbVie Inc. (Chicago, IL, USA).

TRIAL REGISTRATION NUMBER

Not applicable.