Intraoperative imaging of pancreas transplant allografts using indocyanine green with laser fluorescence

Intraoperative indocyanine green angiography for predicting postoperative hypoparathyroidism

BACKGROUND

Postoperative hypocalcemia is a common complication of thyroidectomy. This problem is most often associated with accidental devascularization or excision of the parathyroid glands (PG).

AIM

Aim was to study near-infrared (NIR) fluorescent imaging with intraoperative PG indocyanine green (ICG) angiography to help identify and preserve PG during total thyroidectomy in order to avoid postoperative hypocalcemia.

MATERIAL AND METHODS

From 2017 to 2022, a total of 92 patients underwent total thyroidectomy at Odessa Regional Hospital. Indications for surgery were multinodular goiter (n = 42), thyroid cancer (n = 43), and Graves' disease (n = 7). By randomization all patients were divided into two groups: in the control group, 48 patients underwent standard total thyroidectomy, and in the main group, 44 patients underwent NIR-assisted total thyroidectomy with ICG angiography. Serum calcium and parathyroid hormone levels were compared between the two groups of patients in 1, 7-15 days after surgery and then 3, 6 months later.

RESULTS

In the control group, based on a visual assessment of the PG, autotransplantation of the PG was conducted in only five cases. In the second group, autotransplantation was performed in 16 patients. The transient postoperative hypocalcemia was observed in 8 patients of the control group (16, 70%) and in the 2 patients of ICG group (4, 50%) on 5-10 postoperative days. In the first group, 2 patients at 3 months after surgery had permanent hypocalcaemia.

CONCLUSION

NIR fluorescent imaging with intraoperative PG ICG angiography is a safe and an easily repeatable method. This technique provides improved detecting and assessment of the perfusion of the PG. The need for autotransplantation of the PG can be determined more objectively using ICG imaging than simple visualization.

Use of Indocyanine Green and Fluorescence Angiography in Parathyroid Surgery: A Feasibility Study

Background. Indocyanine green (ICG) with near-infrared (NIR) fluorescence is an established method for assessing vascularity in various clinical settings. We hypothesized that parathyroid adenomas, with increased capillary networks, may demonstrate a fluorescence which could aid intraoperative identification and confirmation of the abnormal parathyroid tissue. Methods. This prospective case-control study compared patients with primary hyperparathyroidism undergoing parathyroidectomy (cases) to normal parathyroid in thyroidectomy patients (controls). After exposing the parathyroid gland, ICG was injected and the fluorescence of parathyroid and thyroid was recorded and graded in comparison to the surrounding tissue and vasculature (0 = nonfluorescent and 5 = vasculature). Results. The intensity of parathyroid fluorescence was more in cases (4 ± 2) than controls (2 ± 1) when graded intraoperatively (P = .001). Thyroid fluorescence did not differ (3 vs 3, P = .072); however, parathyroid fluorescence was more intense than thyroid in cases (parathyroid = 4 ± 2 and thyroid = 3 ± 1, P = .018). Conclusions. ICG fluorescence in diseased parathyroid was more intense than normal parathyroid and thyroid, suggesting the ICG/NIR technology may be a useful intraoperative tool for identification of abnormal parathyroid.

Outcomes using indocyanine green angiography with perforator-sparing component separation technique for abdominal wall reconstruction

BACKGROUND

Usage of intraoperative indocyanine green (ICG) to assess skin flaps prior to abdominal wall closure has been shown to decrease postoperative wound-related complications. Primary outcome assessed is the utility of ICG in intraoperative decision making. Secondary outcomes analyzed are the incidence of surgical site occurrence (SSO) and hernia recurrence rates.

METHODS

A retrospective study using the MedStar Georgetown University Hospital database was conducted, incorporating all consecutive patients undergoing complex incisional hernia repair from 2008 to 2018. 146 patients underwent perforator-sparing component separation (PSCST), 88 underwent flap assessment using intraoperative ICG angiography; they were then analyzed based on patient comorbidities, Ventral Hernia Working Group grade, operative factors, and complications.

RESULTS

A total of 146 patients were analyzed with no statistical difference in patient characteristics between the SPY and no SPY group except in BMI (30.2 vs. 33.2 kg/m², p = 0.036). The no SPY group also had higher numbers of patients undergoing concurrent panniculectomy (12 vs. 1, p < 0.001), and extensive lysis of adhesions (30 vs. 31, p = 0.048). Of the 88 patients undergoing intraoperative SPY, 37 (42%) patients had a change of intraoperative management as defined by further subcutaneous skin flap debridement. Despite this change, there was no statistical difference in incidence of SSO between SPY and no SPY (24.3% vs. 11.8%, p = 0.12), and no difference in hernia recurrence rates 5.6% (n = 5) versus 13.7% (n = 8), p = 0.09.

CONCLUSION

Intraoperative ICG assessment of subcutaneous skin flaps with a perforator-sparing component separation does not result in a decrease in surgical site occurrences.

The use of near-infrared fluorescence imaging in endocrine surgical procedures

Near-infrared fluorescence imaging in endocrine surgery is a new, yet highly investigated area. It involves indocyanine green use as well as parathyroid autofluorescence. Several groups have described their technique and reported on the observed utility. However, there is no consensus on technical details. Furthermore, the correlation between intraoperative findings and postoperative outcomes is unclear. With this study, we aim to review the current literature on fluorescence imaging and share our insights on technical details.

Intraoperative indocyanine green fluorescence angiography to predict wound complications in complex ventral hernia repair

INTRODUCTION

Complex ventral hernia repair (VHR) is associated with a greater than 30% wound complication rate. Perfusion mapping using indocyanine green fluorescence angiography (ICG-FA) has been demonstrated to predict skin and soft tissue necrosis in many reconstructive procedures; however, it has yet to be evaluated in VHR.

METHODS

Patients undergoing complex VHR involving component separation and/or extensive subcutaneous advancement flaps were included in a prospective, blinded study. Patients with active infection were excluded. ICG-FA was performed prior to incision and prior to closure, but the surgeon was not allowed to view it. An additional blinded surgeon documented wound complications and evaluated postoperative photographs. The operative ICG-FA was reviewed blinded, and investigators were then unblinded to determine its ability to predict wound complications.

RESULTS

Fifteen consecutive patients were enrolled with mean age of 56.1 years and average BMI of 34.9, of which 60% were female. Most (73.3%) had prior hernia repairs (average of 1.8 prior repairs). Mean defect area was 210.4 cm2, mean OR time was 206 min, 66.6% of patients underwent concomitant panniculectomy, and 40% had component separation. Mean follow-up was 7 months. Two patients developed wound breakdown requiring reoperation, while 1 had significant fat necrosis and another a wound infection, requiring operative intervention. ICG-FA was objectively reviewed and predicted all 4 wound complications. Of the 12 patients without complications, 1 had an area of low perfusion on ICG-FA. This study found a sensitivity of 100% and specificity of 90.9% for predicting wound complications using ICG-FA.

CONCLUSION

In complex VHR patients, subcutaneous perfusion mapping with ICG-FA is very sensitive and has the potential to reduce cost and improve patient quality of life by reducing wound complications and reoperation.

Fluorescent angiography

Fluorescent angiography is a simple and effective real-time tool for measurement of tissue perfusion both in and out of the operating room. It has multiple uses including: (1) identifying perforating vessels during flap planning; (2) locating primary and secondary angiosomes within a prepared flap; (3) as an aid in decision making for tissue debridement and flap creation; (4) intraoperative evaluation of microanastomoses; (5) postoperative flap monitoring, and (6) documentation of perfusion. The technology is easy to use in the hands of the operating surgeon and is safe for the patient, as it requires no radiation exposure.

Intraoperative evaluation of blood perfusion by laser-assisted indocyanine green angiography after ex vivo vascular reconstruction of intrahilar renal artery aneurysm

The surgical reconstruction of intrahilar renal artery aneurysms (RAAs) is a difficult surgery because of complex anatomy. We present a case of right intrahilar RAA diagnosed in a 67-year-old man. We performed ex vivo reconstruction using an organ preservation solution to prevent postoperative renal failure. We assessed graft patency and blood perfusion was assessed by laser-assisted indocyanine green angiography using the SPY system after autotransplantation. Postoperative renal insufficiency was not observed. The results demonstrate that ex vivo reconstruction of intrahilar RAAs using an organ preservation solution, and graft patency and blood perfusion evaluation using the SPY system are effective methods for preserving renal function.

Near-infrared imaging method for the in vivo assessment of the biodistribution of nanoporous silicon particles

In the development of new nanoparticle-based technologies for therapeutic and diagnostic purposes, understanding the fate of nanoparticles in the body is crucial. We recently developed a multistage vector delivery system comprising biodegradable and biocompatible nanoporous silicon particles (first-stage microparticles [S1MPs]) able to host, protect, and deliver second-stage therapeutic and diagnostic nanoparticles (S2NPs) on intravenous injection. This delivery system aims at sequentially overcoming the biologic barriers en route to the target delivery site by separating and assigning tasks to the coordinated logic-embedded vectors constituting it. In this work, by conjugating a near-infrared dye on the surface of the S1MP without compromising the porous structure and potential loading of S2NPs, we were able to monitor the in vivo distribution of S1MPs in healthy mice using an optical imaging system. It was observed that particles predominantly accumulated in the liver and spleen at the end of 24 hours. Further quantification of S1MPs in the major organs of the animals by elemental analysis of silicon using inductively coupled plasma-atomic electron spectroscopy verified the accuracy of in vivo near-infrared imaging as a tool for evaluation of nanovector biodistribution.