Gastroduodenal artery aneurysm - an extremely rare but insidious cause of abdominal pain: a case report.

An arterial aneurysm is a localized weakening of the artery wall that results in pathological dilatation. All intra-abdominal artery aneurysms are labeled as visceral artery aneurysms (VAA), apart from the aorto-iliac artery aneurysms. VAA´s are rare, gastroduodenal artery aneurysms (GDAA), constituting 1.5% of visceral artery aneurysms. A woman in her early 80s´ presented with chronic epigastric pain, weight loss, and nausea. Conservative management was unsuccessful. Imaging revealed a GDAA, prompting endovascular coil embolization. Subsequent evaluation confirmed Polyarteritis Nodosa (PAN), treated with rituximab. The report underscores the diagnostic challenges, emphasizing the need for a multidisciplinary approach using imaging and angiography. GDAA's potential life-threatening rupture necessitates prompt intervention, as illustrated in this case. The rare association with PAN, although infrequent, underscores the importance of considering underlying etiologies in multiple visceral aneurysms. Early diagnosis and intervention are pivotal for this uncommon yet potentially lethal condition.

Proton pump inhibitor therapy after transcatheter angiography in refractory nonvariceal acute upper gastrointestinal bleeding patients: a cohort study.

BACKGROUND: Transcatheter angiography (TA) could help to diagnose and treat refractory nonvariceal upper gastrointestinal bleeding (NVUGIB). Proton pump inhibitors (PPIs) are the key medication for reducing the rebleeding rate and mortality and are usually continued after TA. It is unknown whether high-dose PPIs after TA are more effective than the standard regimen. METHODS: We retrospectively collected data from patients who received TA because of refractory NVUGIB from 2010 to 2020 at West China Hospital. 244 patients were included and divided into two groups based on the first 3 days of PPIs treatment. All baseline characteristics were balanced using the inverse probability of treatment weighting method. The 30-day all-cause mortality, rebleeding rate and other outcomes were compared. The propensity score matching method was also used to verify the results. RESULTS: There were 86 patients in the high-dose group and 158 in the standard group. The average daily doses of PPI were 192.1 ± 17.9 mg and 77.8 ± 32.0 mg, respectively. Cox regression analysis showed no difference in the 30-day all-cause mortality (aHR 1.464, 95% CI 0.829 to 2.584) or rebleeding rate (aHR 1.020, 95% CI 0.693 to 1.501). There were no differences found in red blood cell transfusion, hospital stay length and further interventions, including endoscopy, repeating TA, surgery and ICU admission. The results were consistent in the subgroup analysis of patients with transcatheter arterial embolization. CONCLUSION: In refractory NVUGIB patients who received TA, regardless of whether embolization was performed, high-dose PPI treatment did not provide additional benefits compared with the standard regimen.

Quantifying Inferior Vena Cava Compliance and Distensibility in an In Vivo Ovine Model Using 3D Angiography.

Synthetic vascular grafts overcome some challenges of allografts, autografts, and xenografts but are often more rigid and less compliant than the native vessel into which they are implanted. Compliance matching with the native vessel is emerging as a key property for graft success. The current gold standard for assessing vessel compliance involves the vessel's excision and ex vivo biaxial mechanical testing. We developed an in vivo method to assess venous compliance and distensibility that better reflects natural physiology and takes into consideration the impact of a pressure change caused by flowing blood and by any morphologic changes present. This method is designed as a survival procedure, facilitating longitudinal studies while potentially reducing the need for animal use. Our method involves injecting a 20 mL/kg saline bolus into the venous vasculature, followed by the acquisition of pre and post bolus 3D angiograms to observe alterations induced by the bolus, concurrently with intravascular pressure measurements in target regions. We are then able to measure the circumference and the cross-sectional area of the vessel pre and post bolus. With these data and the intravascular pressure, we are able to calculate the compliance and distensibility with specific equations. This method was used to compare the inferior vena cava's compliance and distensibility in native unoperated sheep to the conduit of sheep implanted with a long-term expanded polytetrafluorethylene (PTFE) graft. The native vessel was found to be more compliant and distensible than the PTFE graft at all measured locations. We conclude that this method safely provides in vivo measurements of vein compliance and distensibility.

Complicaciones tras retirada de barra de Nussen pectus excavatum. Análisis y propuesta de unprotocolo de seguridad / Complications after Nuss bar removal procedure for pectus excavatum. Analysis and proposal of a safety protocol

Objetivo: La retirada de la barra de Nuss puede provocar diversascomplicaciones, algunas leves y otras potencialmente mortales. Su incidencia puede verse reducida con una preparación quirúrgica adecuaday siguiendo ciertos pasos de seguridad. El presente estudio tiene porobjeto analizar nuestra experiencia con las complicaciones acontecidasdurante la retirada de la barra, así como nuestro protocolo de seguridadpara la prevención y el manejo de dichas complicaciones.Material y métodos:Estudio de cohortes observacional llevado acabo a partir del análisis retrospectivo de todos los pacientes sometidos acirugía de retirada de barra de Nuss entre noviembre de 2013 y marzo de2022 en un hospital universitario. Se analizaron las siguientes variables:demografía de los pacientes, presencia de comorbilidades, tiempo desdela colocación de la barra hasta su retirada, y complicaciones operatoriasy postoperatorias. El estudio se realizó conforme a las directrices de laPROCESS Guideline. Resultados: Se incluyó a 40 pacientes, 37 de ellos varones. En 17pacientes se retiró una barra, y en 22, dos. La edad media en el momento de la cirugía fue de 17,5 años (percentil 25-75%: 16,75 - 19,25).El tiempo transcurrido desde la colocación hasta la retirada fue de 26meses (percentil 25-75%: 23,75 - 30,25). Se registraron 10 complicaciones en 9 pacientes (22,5%), 6 de clase I según la clasificación deClavien-Dindo (67%), 2 de clase II (22%), 1 de clase IIIb y 1 de claseIV. La complicación hemorrágica motivó la creación de un protocolo deseguridad para disminuir la incidencia de las complicaciones. Conclusión: La retirada de la barra de Nuss es un procedimientoseguro, habitualmente con escasas complicaciones, aunque en ocasionespueden ser graves. Para evitarlas, es importante contar con un protocoloque garantice la seguridad.(AU)

Objective: The Nuss bar removal procedure may bring about different complications. Some are mild while others can be life-threatening.An adequate surgery setup and the fulfilment of some security stepsmay reduce their incidence. This study aims to analyze our experiencewith the complications that occurred during bar removal and our safetyprotocol for the prevention and management of these complications.Materials and methods: Observational cohort study from a retrospective chart review of all patients who underwent Nuss bar removalfrom November 2013 to March 2022 at a University hospital. Variablesanalyzed include patients’ demographics; presence of comorbidities;time elapsed from bar placement to removal, and the occurrence ofoperative and postoperative complications. Study written under the´PROCESS Guideline’. Results: Fourty (40) patients were included in the study; 37 weremale. One bar was removed in 17 patients and two in 22 patients. Medianage at surgery: 17.5 years (Percentile 25-75%: 16.75 - 19.25). Timeelapsed from placement to removal: 26 months (Percentile 25 - 75%:23.75 - 30.25). Complications: 10 in 9 patients (22.5%); 6 Clavien-Dindoclass I (67%); 2 class II (22%); 1 class IIIb, 1 class IV. The hemorrhagiccomplication motivated the development of a safety protocol to reduceincidence of complications. Conclusion: Nuss bar removal is a safe procedure with usuallyscant complications. Nonetheless, these may be serious sometimes. Toprevent them, a protocol for a safe procedure is important.(AU)

Displasia fibromuscular y síndrome de ligamento arcuato medio. Infrecuentesy simultáneos / Fibromuscular dysplasia and median arcuate ligament syndrome. Rare and simultaneous findings

Introducción: la displasia fibromuscular (DFM) es una patología poco frecuente de la capa muscular de las arterias. El síndrome de ligamento arcuato medio (SLAM) es una entidad infrecuente causada por la compresión extrínseca del tronco celíaco por el diafragma. Caso clínico: presentamos el caso de una mujer joven con DFM diagnosticada de afectación a nivel del tronco celíaco y de la arteria hepática común. Ante clínica de dolor abdominal, se solicita angio TC, que describe un SLAM asociado a la DFM. Se decide sección quirúrgica del ligamento arcuato y descompresión del tronco celíaco mediante abordaje robótico. Discusión: en ambas entidades la angiografía es el trataminto de referencia para el diagnóstico. El tratamiento de primera línea de la DFM es el endovascular mediante angioplastia, y del SLAM, el quirúrgico, seccionando el ligamento arcuato.(AU)

Introduction: fibromuscular dysplasia (FMD) is a rare disorder that affects the muscular layer of the arteries. The medianarcuate ligament syndrome (MALS) is also a rare disorder due to the extrinsic compression of the celiac trunk by thediaphragm.Case report: we report the case of a young woman with FMD and splachnic involvement of the celiac trunk and thecommon hepatic artery level. After presenting with abdominal pain, a CCTA was performed that revealed the presenceof FMD-related MALS. The surgical section of the arcuate ligament and decompression of celiac trunk were decided andperformed through robotic approach.Discussion: the gold standard for the diagnosis of both entities is angiography. However, while the first-line therapy ofFMD is endovascular, in the case MALS the best alternative is surgical treatment sectioning the arcuate ligament.(AU)

Transesophageal Echocardiography-Guided Elephant Trunk Procedure for Repair of Descending Thoracic Aorta: A Case Report.

ABSTRACT: The elephant trunk procedure, an endovascular strategy for retrograde type A acute aortic dissection, is associated with several complications, hemolytic anemia being a rare one. We performed endovascular stent-graft insertion in a patient who developed hemolytic anemia. Transesophageal echocardiography (TEE) detected turbulent jet flow and stenosis position, which was not detected by angiography and intravascular ultrasound (IVUS). This imaging technique proved effective for malperfusion diagnosis and enabled us to confirm its resolution after the endovascular procedure. Intraoperative TEE is a useful adjunct to angiography and IVUS for diagnosis and therapeutic assessment during endovascular repair of a stenosed elephant trunk.

Endovascular repair of bilateral isolated common iliac artery aneurysms with unsuitable anatomy utilizing an aortic bifurcated unibody endograft and modified sandwich technique to preserve pelvic blood flow: a case series.

Bilateral isolated common iliac artery aneurysms (CIAAs) are rare, and endovascular repair of CIAAs has emerged as an alternative to traditional open surgical repair. The primary goal of therapy is to exclude the aneurysm sac while maintaining perfusion of at least one internal iliac artery (IIA) to prevent pelvic ischemia. Although the iliac branch device (IBD) has improved the feasibility of preserving the IIA, its applicability is limited to a specific subset of aneurysm anatomy. We present a case series of three patients with bilateral isolated CIAAs in whom preoperative CT scans revealed an absence of a landing zone, the diameter of proximal CIA diameter was less than 13.0 mm, and normal diameter of the nonaneurysmal infrarenal aorta, making it challenging to use an IBD alone or a standard bifurcated aortic endograft to provide a proximal landing zone for iliac artery stenting. To overcome the small diameter of the infrarenal aorta, we implanted an aortic bifurcated unibody endograft. Then, we utilized a balloon-expandable covered stent-graft with overdilation as a modified sandwich technique to create an "eye of the tiger" configuration to prevent gutter leakage. The final angiography performed during the procedure revealed successful exclusion of the aneurysms, with blood flow to the right IIA and no type III endoleak. During the postoperative follow-up period, no patients exhibited symptoms associated with pelvic ischemia. There were no endoleaks or sac expansions on the two-year follow-up CT scans, and all external and internal iliac graft limbs were patent. This study demonstrated that a combination of an aortic bifurcated unibody endograft and a modified sandwich technique can effectively treat bilateral isolated CIAAs with certain anatomical constraints.

Influencing factors on the time to CT in suspected pulmonary embolism: an explorative investigation.

Pulmonary embolism is a potentially fatal condition with increased mortality if anticoagulation is delayed. This study aimed to find influencing factors on the duration from requesting a computed tomography (CT) pulmonary angiography (CTPA) to performing a CTPA in suspected acute pulmonary embolism. In 1849 cases, automatically generated time data were extracted from the radiological information system. The impact of the distance to the scanner, case-related features (sector of patient care, triage), and workload (demand for CTs, performed CTs, available staff, hospital occupancy) were investigated retrospectively using multiple regression. The time to CTPA was shorter in cases from the emergency room (ER) than in inpatients and outpatients at distances below 160 m and 240 m, respectively. While requests from the ER were also performed faster than cases from regular wards (< 180 m), no difference was found between the ER and intensive care units. Compared to "not urgent" cases, the workflow was shorter in "urgent" (- 17%) and "life-threatening" (- 67%) situations. The process was prolonged with increasing demand (+ 5%/10 CTs). The presented analysis identified relevant in-hospital influences on the CTPA workflow, including the distance to the CT together with the sector of patient care, the case triage, and the demand for imaging.

Massive retroperitoneal hematoma caused by intercostal artery bleeding after blunt trauma: a case report.

BACKGROUND: The occurrence of massive retroperitoneal hematoma caused by intercostal artery bleeding is exceedingly uncommon. CASE PRESENTATION: A middle-aged male presented to the hospital after a fall. Computed tomography scan revealed a massive retroperitoneal hematoma without any evidence of organ or major vessel rupture. The angiogram revealed extravasation from a branch of the twelfth intercostal artery, and successful transcatheter arterial embolization was performed on this specific artery. CONCLUSIONS: The possibility of intercostal artery rupture should be considered in cases of retroperitoneal hematomas, and accurate diagnosis can be achieved through imaging studies. Transcatheter arterial embolization represents an effective treatment modality.

Nomogram-based geometric and hemodynamic parameters for predicting the growth of small untreated intracranial aneurysms.

Previous studies have shown that the growth status of intracranial aneurysms (IAs) predisposes to rupture. This study aimed to construct a nomogram for predicting the growth of small IAs based on geometric and hemodynamic parameters. We retrospectively collected the baseline and follow-up angiographic images (CTA/ MRA) of 96 small untreated saccular IAs, created patient-specific vascular models and performed computational fluid dynamics (CFD) simulations. Geometric and hemodynamic parameters were calculated. A stepwise Cox proportional hazards regression analysis was employed to construct a nomogram. IAs were stratified into low-, intermediate-, and high-risk groups based on the total points from the nomogram. Receiver operating characteristic (ROC) analysis, calibration curves, decision curve analysis (DCA) and Kaplan-Meier curves were evaluated for internal validation. In total, 30 untreated saccular IAs were grown (31.3%; 95%CI 21.8%-40.7%). The PHASES, ELAPSS, and UIATS performed poorly in distinguishing growth status. Hypertension (hazard ratio [HR] 4.26, 95%CI 1.61-11.28; P = 0.004), nonsphericity index (95%CI 4.10-25.26; P = 0.003), max relative residence time (HR 1.01, 95%CI 1.00-1.01; P = 0.032) were independently related to the growth status. A nomogram was constructed with the above predictors and achieved a satisfactory prediction in the validation cohort. The log-rank test showed significant discrimination among the Kaplan-Meier curves of different risk groups in the training and validation cohorts. A nomogram consisting of geometric and hemodynamic parameters presented an accurate prediction for the growth status of small IAs and achieved risk stratification. It showed higher predictive efficacy than the assessment tools.

Comparative Analysis of Angiographic Parameters and Percutaneous Coronary Intervention Outcomes in Diverse Populations in Türkiye.

OBJECTIVE: Due to the conflict in Syria since 2011, more than 3.5 million Syrian citizens reside in Türkiye. Because Syrian patients were underrepresented in previous studies on percutaneous coronary intervention (PCI) outcomes, we aimed to analyze the severity of coronary artery disease and in-hospital outcomes of PCI in this population. METHODS: We retrospectively analyzed 142 Syrian patients who underwent PCI at our center between June 2020 and October 2022 and compared the data with that of age- and sex-matched Turkish patients (n = 271) who also underwent PCI. We assessed comorbidities, coronary anatomy features, procedural complications, and in-hospital cardiovascular outcomes (Major Adverse Cardiac and Cerebrovascular Events, MACCE). RESULTS: The mean age of the study population was 57 ± 12 years, with 15% being female. Clinical indication and coronary anatomy features did not differ between the groups. However, the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score was higher in Syrian patients compared to Turkish patients (16 [11-22] vs. 12 [8-20]; P < 0.001). Complex PCI rates, in-hospital bleeding and contrast nephropathy were similar in both groups. MACCE was comparable between Syrian and Turkish patients (13 [4.8%] vs. 13 [9.2%], P = 0.083). CONCLUSION: Comparable MACCE rates were observed in both ethnic groups undergoing PCI, despite a higher SYNTAX score in Syrian patients. Future research should investigate whether similar in-hospital MACCE rates are observed in other regions of Türkiye and whether long-term cardiovascular outcomes differ between Turkish and Syrian patients.

Early and mid-term results after endovascular repair of thoracoabdominal aortic aneurysms using the off-the-shelf multibranched t-Branch device: a national multi-center study.

Objective: The multibranched off-the-shelf Zenith® t-Branch (Cook Medical, Bloomington, IN) device is commonly chosen for endovascular repair of thoracoabdominal aortic aneurysms. The aim of this study was to report early and mid-term outcomes in all patients treated with the t-Branch in Norway; Design and Methods: A retrospective multicenter study with Norwegian centers performing complex endovascular aortic repair was undertaken. T-Branch patients from 2014 to 2020 were included. All postoperative computed tomography angiography images were reviewed, and demographic, anatomical, perioperative and follow-up data were analyzed; Results: Seventy patients were treated in a single-step (n = 55) or staged (n = 15) procedure. Symptomatic presentation was seen in 20 patients, six of which had a contained rupture. Technical success was 87% (n = 59), with failures caused by unsuccessful bridging of target vessels (n = 4), target vessel bleeding (n = 3), persisting type 1c endoleak (n = 1) and t-Branch malrotation (n = 1). 30-day mortality was 9% (n = 6) and was associated with high BMI (p = .038). The spinal cord ischemia rate was 21% (n = 15) and was associated with type II aneurysms (OR 5.4, 95% CI 1.1-26.7, p = .04), smoking (OR 6.0, 95% CI 1.3-27.6, p = .02) and intraoperative blood loss (OR 1.1, 95% CI 1.0-1.3, p = .01). Survival at one, two and three years was 84 ± 4%, 70 ± 6% and 67 ± 6%, respectively. Freedom from aortic-related reinterventions at one, two and three years was 80 ± 5%, 65 ± 7% and 50 ± 8%, respectively; Conclusion: The study showed low early mortality (9%) and satisfactory mid-term survival. Technical success was achieved in acceptable 87% of procedures. The rate of spinal cord ischemia was high, occurring in 21% of patients.

This paper provides a national experience of all TAAA patients treated with the multibranched t-Branch stent graft in Norway in a multi-center study. As we aimed at including all Norwegian patients operated with the device, the paper adds real-world data on t-Branch outcomes from four regional smaller-volume vascular centers.The paper provides technical and clinical mid-term results with several patients being followed up for >3 years.Technical success was achieved in 87% of procedures.The 30-day mortality rate was 9% and survival at one, two and three years was 85 ± 4%, 70 ± 6% and 67 ± 6%, respectively.Spinal cord ischemia was associated with Crawford type II aneurysms, smoking and intraoperative blood loss.

Risk factors of internal carotid artery stenosis in patients with proliferative diabetic retinopathy: an analysis using optical coherence tomography and optical coherence tomography angiography.

BACKGROUND: This research investigates the correlation between the severity of internal carotid artery (ICA) stenosis and retinal parameters in patients with proliferative diabetic retinopathy (PDR), aiming to uncover potential risk factors. METHODS: A retrospective analysis of 68 patients (136 eyes) diagnosed with bilateral PDR from January 1, 2017, to December 31, 2021, was conducted. Carotid artery stenosis (CAS) was assessed using neck computed tomography angiography (CTA) and carotid duplex ultrasound (CDUS), with stenosis classified into two groups: normal (group 1) and mild or above (group 2), based on the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Optical coherence tomography (OCT) and OCT angiography (OCTA) measured several retinal parameters, including sub foveal choroidal thickness (SFCT), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, vessel density (VD), and foveal avascular zone (FAZ) area. Statistical analyses determined correlations between ICA degrees and retinal parameters. RESULTS: This study showed significant differences between groups in total VD, FAZ area, total RNFL thickness, and temporal RNFL thickness, indicating that patients with more severe ICA stenosis had noticeable retinal changes. Other parameters such as hyperlipidemia, total cholesterol levels, and intraocular pressure (IOP) also differed significantly, while no notable differences were observed in SFCT, central VD, average GCIPL, and superior, nasal, and inferior RNFL thickness. CONCLUSION: The study findings highlight retinal changes, such as an increased FAZ area, decreased total VD, and a total and thinner temporal RNFL, which suggest the need for carotid artery evaluation in patients. These findings have important clinical implications for the need for carotid work up in patients with PDR.

Successful Transcatheter Arterial Embolization of Abdominal Wall Hematoma from the Left Deep Circumflex Iliac Artery after Abdominal Paracentesis in a Patient with Liver Cirrhosis: Case Report and Literature Review.

The occurrence of an abdominal wall hematoma caused by abdominal paracentesis in patients with liver cirrhosis is rare. This paper presents a case of an abdominal wall hematoma caused by abdominal paracentesis in a 67-year-old woman with liver cirrhosis with a review of the relevant literature. Two days prior, the patient underwent abdominal paracentesis for symptom relief for refractory ascites at a local clinic. Upon admission, a physical examination revealed purpuric patches with swelling and mild tenderness in the left lower quadrant of the abdominal wall. Abdominal computed tomography revealed advanced liver cirrhosis with splenomegaly, tortuous dilatation of the para-umbilical vein, a large volume of ascites, and a large acute hematoma at the left lower quadrant of the abdominal wall. An external iliac artery angiogram showed the extravasation of contrast media from the left deep circumflex iliac artery. Embolization of the target arterial branches using N-butyl-2-cyanoacrylate was then performed, and the bleeding was stopped. The final diagnosis was an abdominal wall hematoma from the left deep circumflex iliac artery after abdominal paracentesis in a patient with liver cirrhosis.

Practicality and Hemodynamic Advantage of Microvascularly Augmented Pectoralis Major Musculocutaneous Flap: Technical Approach and Evidence Based on Indocyanine Green Angiography.

ABSTRACT: We have recently shown that including the blood flow from the lateral thoracic artery (LTA) in addition to the thoracoacromial artery in the pectoralis major muscle musculocutaneous (PMMC) flap (bipedicle PMMC flap) can increase the perfusion of the flap. We also developed the concept of the supercharged PMMC flap, in which the LTA included in the flap was once cut and anastomosed to a cervical artery under a microscope. It is an effective solution to maintain the additional blood flow from the LTA, when the length of the LTA is compromised for reconstruction. The mandibular reconstruction of an oral cancer patient was performed with a supercharged PMMC flap. Intraoperative indocyanine green angiography was performed in a single pedicle, bipedicle, and supercharged conditions, and the videos were analyzed with a quantitative assessment system of perfusion using some parameters. As a result, blood supply from the LTA was essential for flap survival in this patient, and supercharging from the cervical artery improved flap perfusion compared with the perfusion in the bipedicle condition. The supercharged PMMC flap can resolve the compromise of pedicle length and be also hemodynamically advantageous, thus making the reconstruction more reliable than the conventional technique.

Long-term Intravital Investigation of an Orthotopic Glioma Mouse Model via Optical Coherence Tomography Angiography.

BACKGROUND/AIM: Probing brain tumor microvasculature holds significant importance in both basic cancer research and medical practice for tracking tumor development and assessing treatment outcomes. However, few imaging methods commonly used in clinics can noninvasively monitor the brain microvascular network at high precision and without exogenous contrast agents in vivo. The present study aimed to investigate the characteristics of microvasculature during brain tumor development in an orthotopic glioma mouse model. MATERIALS AND METHODS: An orthotopic glioma mouse model was established by surgical orthotopic implantation of U87-MG-luc cells into the mouse brain. Then, optical coherence tomography angiography (OCTA) was utilized to characterize the microvasculature progression within 14 days. RESULTS: The orthotopic glioma mouse model evaluated by bioluminescence imaging and MRI was successfully generated. As the tumor grew, the microvessels within the tumor area slowly decreased, progressing from the center to the periphery for 14 days. CONCLUSION: This study highlights the potential of OCTA as a useful tool to noninvasively visualize the brain microvascular network at high precision and without any exogenous contrast agents in vivo.

Optical coherence tomography angiography analysis methods: a systematic review and meta-analysis.

Optical coherence tomography angiography (OCTA) is widely used for non-invasive retinal vascular imaging, but the OCTA methods used to assess retinal perfusion vary. We evaluated the different methods used to assess retinal perfusion between OCTA studies. MEDLINE and Embase were searched from 2014 to August 2021. We included prospective studies including ≥ 50 participants using OCTA to assess retinal perfusion in either global retinal or systemic disorders. Risk of bias was assessed using the National Institute of Health quality assessment tool for observational cohort and cross-sectional studies. Heterogeneity of data was assessed by Q statistics, Chi-square test, and I2 index. Of the 5974 studies identified, 191 studies were included in this evaluation. The selected studies employed seven OCTA devices, six macula volume dimensions, four macula subregions, nine perfusion analyses, and five vessel layer definitions, totalling 197 distinct methods of assessing macula perfusion and over 7000 possible combinations. Meta-analysis was performed on 88 studies reporting vessel density and foveal avascular zone area, showing lower retinal perfusion in patients with diabetes mellitus than in healthy controls, but with high heterogeneity. Heterogeneity was lowest and reported vascular effects strongest in superficial capillary plexus assessments. Systematic review of OCTA studies revealed massive heterogeneity in the methods employed to assess retinal perfusion, supporting calls for standardisation of methodology.