A case report of duodenal arteriovenous malformation: usefulness of intraoperative indocyanine green angiography for precise identification of the lesion

Background Arteriovenous malformation (AVM) of the gastrointestinal (GI) tract can cause bleeding. The treatment choice for GI tract AVM is surgical resection of the involved bowel segment with complete resection of the nidus. The AVM formed in the duodenum or pancreatic head could also cause gastrointestinal bleeding, and there are several reports of pancreaticoduodenectomy as its treatment. However, if the area of AVM can be accurately identified during surgery, it may be possible to completely resect the AVM while preserving the organ. We report a case of duodenal AVM in a patient successfully treated with a subtotal stomach-preserving duodenal bulb resection using intraoperative indocyanine green (ICG) angiography technique. Case presentation An 18-year-old man was diagnosed with duodenal AVM after several examinations for anemia and was referred to our hospital for further treatment. Preoperative imaging studies showed that the inflow vessels of this duodenal AVM were the inferior pyloric artery and the superior duodenal artery, and the AVM was localized to the duodenal bulb. Thereafter, stomach-preserving duodenal bulb resection preceded by ligation of the inflow vessels was performed. During the surgery, ICG angiography clearly demonstrated the area, where the nidus was distributed, and a duodenal bulb resection with complete resection of the AVM was successfully performed. There was no recurrence at the 6-month follow-up. Conclusions Intraoperative ICG angiography was a useful procedure for precise identification of the AVM of the GI tract.

Towards Quantitative ICG Angiography: Fluorescence Monte Carlo Multi Cylinder

Intraoperative blood flow measurement is an effective way to assess the quality of bypass surgery. Flow quantification from indocyanine green (ICG) angiography promises to be an easy, contact-free method. It shows deviations compared to a reference. These are given as factor k, which depends on the vessel diameter d. The radiation transport within the vessel while recording the ICG passage might cause this. It is analyzed in silico to disclose its impact on k (d). A Fluorescence Monte Carlo Multi Cylinder (FMCMC) model was developed as a static model, assuming homogeneous concentration of ICG. In contrast to published approaches utilizing a Monte Carlo Multi Layer (MCML) model assuming the deepest penetration location within a photon packet’s path to be the fluorescence location, the events are modeled. Fluorescence event modeling, Multi Cylinder geometry and a homogeneous illumination as well as combinations of these were implemented in separate aspect models. Resulting k (d) were compared to k (d) from MCML. Deviations in k (d) derived from FMCMC and MCML in each aspect model were present. The Root Mean Square Error ranges from 6,8% to 36 %, k (d) also varied comparing the aspect models to each other. The model geometry, the modeled fluorescence location and illumination mode show a clear impact on simulated k (d). Therefore, our study shows that simplifications of previous studies are invalid. The developed FMCMC model considers the named aspects, allowing the analysis of radiation transport in ICG angiography. The FMCMC model assumes a homogeneous concentration of ICG which is not true in clinical cases. Obtaining the heterogeneous distribution of ICG is possible via fluid flow models. Coupling the fluid flow model and the developed radiation transport model as well as including a detailed camera optic is the task for future work.

Thermal Laser Monotherapy for Extrafoveal Polypoidal Choroidal Vasculopathy

Introduction Polypoidal choroidal vasculopathy (PCV) is a vascular disease of the choroid. Diagnosis is mainly based on polypoidal aneurysm-like lesions seen in indocyanine green (ICG) angiography. Various therapeutic options have been proposed. Methods Outcomes of 10 cases with extrafoveal PCV and consecutive macular edema treated with thermal laser are reported. Diagnosis of PCV was confirmed by ICG angiography. Results Upon successful occlusion of the polyps in 10 eyes after thermal laser treatment demonstrated in ICG angiography, a regression of central foveal edema was seen in optical coherence tomography and color fundus photography. Visual acuity improved from logMAR 0.8 to logMAR 0.3. Follow-up ranged from 4 months to 15 years, with a median of 1 year. Two eyes had a recurrence of exudative maculopathy 5 and 7 years after laser treatment, respectively. Conclusion A careful differentiation between various subforms of exudative maculopathy using fluorescein and ICG angiography can identify certain selected patients with extrafoveal PCV, for whom thermal laser monotherapy can be a therapeutic option.

Indocyanine Green Angiography for Parathyroid Gland Evaluation during Transoral Endoscopic Thyroidectomy

Indocyanine green (ICG) angiography, a real-time intraoperative imaging technique, is associated with better parathyroid identification and functional evaluation during open thyroidectomy. However, the benefits of ICG fluorescence imaging application in transoral endoscopic thyroidectomy are not well-documented. Consecutive patients who underwent transoral endoscopic thyroidectomy were retrospectively reviewed. Parathyroid glands were assessed with visual inspection followed by ICG angiography. The fluorescence intensity of all parathyroid glands was recorded. In total, 158 parathyroid glands from 60 patients (41 underwent lobectomy and 19 underwent total thyroidectomy) were eligible for evaluation. A total of 135 parathyroid glands (85.4%) were identified, including nine glands (5.7%) that were solely localized because of ICG angiography. Incidental parathyroidectomy occurred in 12 patients with predominant inferior gland (83.3%) and associated with central neck dissection (66.7%). Among patients receiving total thyroidectomy, patients who retained at least one well-perfused parathyroid gland had higher parathyroid hormone (PTH) level and were less likely to develop hypoparathyroidism on postoperative day one than those without any well-perfused ICG-enhanced parathyroid gland (p = 0.038). In addition, the duration of calcium supplementation to maintain normocalcemia was also shorter. ICG angiography is a feasible adjunct procedure for parathyroid identification and postoperative functional prediction in transoral endoscopic thyroidectomy.

Endoscope-Assisted Resection of Extra-Axial Premedullary Neurenteric Cyst via Far Lateral-Supracondylar Approach: 2-Dimensional Operative Video

Neurenteric cysts are rare congenital lesions that may compress the ventral brainstem.1-9 In this operative video, we illustrate the surgical treatment of an intradural extra-axial neurenteric cyst extending from the lower pons to the craniocervical junction. The patient, an asymptomatic 52-yr-old female, underwent surveillance imaging of the premedullary lesion for 14 yr without progression. However, after developing progressive strain-induced headaches, imaging revealed a significant enlargement of the lesion with brainstem compression and partial obstruction of the foramen magnum. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a lateral suboccipital craniotomy and C1 laminectomy through a far lateral approach. The lesion was immediately visualized upon opening the dura. After identifying the cranial nerves, we resected the tumor while taking care to preserve the neurovascular elements of the cerebellopontine angle and foramen magnum. During the resection, we unexpectedly encountered a firm nodule that was adherent to the right posterior inferior cerebellar artery. This was meticulously dissected and removed en bloc using intraoperative indocyanine green (ICG) angiography. The cavity was inspected with 0-degree and 30-degree endoscopes to ensure complete resection of the lesion. Gross total resection was confirmed on postoperative magnetic resonance imaging. The patient was neurologically intact with no cranial nerve abnormalities and discharged home on postoperative day 3. This case demonstrates that the far lateral-supracondylar approach affords safe access to the ventral pontomedullary and craniocervical junctions and that intraoperative adjuncts, including ICG angiography and endoscopic visualization, can facilitate complete lesion resection with excellent clinical outcomes.

Management of post-traumatic ischaemic ileal stricture using intraoperative indocyanine green fluorescence-guided resection

Blunt abdominal trauma can affect mesenteric circulation which may lead to bowel strictures. Indocyanine green (ICG) angiography can be used to assess mesenteric blood flow and bowel perfusion as a guide to resect length intraoperatively. But this concept has not been applied to ischaemic bowel strictures. We present a case of ischaemic ileal stricture induced by blunt abdominal trauma which was managed by resection and anastomosis. Intraoperative near-infrared (NIR) ICG angiography was used as a guide to resect the bowel length. This case emphasises that ischaemic bowel strictures should be suspected in patients presenting with intestinal obstruction following trauma. Resection and anastomosis of the affected segment remains the primary treatment modality with excellent outcomes. NIR ICG angiography is a real-time objective and useful resource for assessing bowel perfusion and could be used to determine the length of the segment to be resected in patients with ischaemic bowel stricture.

Near-infrared fluorescent imaging techniques for the detection and preservation of parathyroid glands during endocrine surgery

Objectives In over 30% of all thyroid surgeries, complications arise from transient and definitive hypoparathyroidism, underscoring the need for real-time identification and preservation of parathyroid glands (PGs). Here, we evaluate the promising intraoperative optical technologies available for the identification, preservation, and functional assessment of PGs to enhance endocrine surgery. Methods We performed a review of the literature to identify published studies on fluorescence imaging in thyroid and parathyroid surgery. Results Fluorescence imaging is a well-demonstrated approach for both in vivo and in vitro localization of specific cells or tissues, and is gaining popularity as a technique to detect PGs during endocrine surgery. Autofluorescence (AF) imaging and indocyanine green (ICG) angiography are two emerging optical techniques to improve outcomes in thyroid and parathyroid surgeries. Near-infrared-guided technology has significantly contributed to the localization of PGs, through the detection of glandular AF. Perfusion through the PGs can be visualized with ICG, which can also reveal the blood supply after dissection. Conclusions Near infrared AF and ICG angiography, providing a valuable spatial and anatomical information, can decrease the incidence of complications in thyroid surgery.