Experimental multiparametric magnetic resonance imaging characterization of iliocaval venous thrombosis pathological changes.

OBJECTIVE: Iliocaval thrombotic obstruction is a challenging condition, especially because thrombus age and corresponding pathological remodeling at presentation are unknown, which directly impacts management. Our aim was to assess the ability of magnetic resonance imaging (MRI) in determining age thresholds of experimentally created inferior vena cava (IVC) thrombosis in pigs. METHODS: We used a previously described swine model of IVC thrombosis. The animals underwent MRI at baseline, immediately after thrombosis creation, and after a follow-up period extending from 2 to 28 days. Thirteen pigs were divided into three groups according to disease chronicity: acute group (AG; n = 5), subacute group (SAG; n = 4), and chronic group (CG; n = 4), with a mean thrombosis age of 6.4 ± 2.5 days, 15.7 ± 2.8 days, and 28 ± 5.7 days, respectively. A T1-weighted volumetric interpolated breath-hold examination sequence was used to anatomically delineate IVC thrombus as a region of interest. Three other MRI sequences were used to assess the thrombus signal. RESULTS: The Kruskal-Wallis test showed a statistically significant difference in T1 relaxation times after contrast injection (P = .026) between the three groups of chronicity. The AG (360.2 ± 102.5 ms) was significantly different from the CG (336.7 ± 55.2 ms; P = .003), and the SAG (354.1 ± 89.7 ms) was significantly different from the AG (P = .027). There was a statistically significant difference in native T2 relaxation times (P = .038) between the three groups. The AG (160 ± 86.7 ms) was significantly different from the SAG (142.3 ± 55.4 ms; P = .027), and the SAG was significantly different from the CG (178.4 ± 11.7 ms; P = .004). CONCLUSIONS: This study highlighted MRI characteristics in a swine model that might have the potential to significantly differentiate subacute and chronic stages from an acute stage of deep vein thrombosis in humans. Further clinical studies in humans are warranted. CLINICAL RELEVANCE: In addition to providing a better understanding of venous thrombosis remodeling over time, magnetic resonance imaging has the potential to be a tool that could allow us to characterize the composition of venous thrombus over an interval, allowing for a refined analysis of the local evolution of venous thrombosis. We propose a noninvasive and innovative method to characterize different thresholds of chronicity with magnetic resonance imaging features of central deep vein thrombosis of the inferior vena cava experimentally obtained using a totally endovascular in vivo swine model, mimicking human pathophysiology. Being able to determine these features noninvasively is critical for vascular specialists when it comes to choosing between fibrinolytic therapy, percutaneous thrombectomy, or surgical management.

Surgical Treatment of Multiple Venous and Arterial Aneurysms Due to Arteriovenous Malformations of the Arm.

Introduction: Arteriovenous malformations (AVMs) are rare, especially in elderly patients. Occasionally, AVM can produce aneurysmal degenerations, which can lead to bleeding or rupture. The aim of this case report was to describe the surgical treatment of large arterial and venous aneurysms in the arm associated with an AVM. Report: An 83 year old woman of White ethnicity who was a non-smoker presented with a large pulsatile aneurysm at the left elbow with paresis of the first three fingers. The diagnosis was made by duplex ultrasonography (DUS), computed tomography angiography (CTA), and arteriography. Additional tests confirmed aneurysms of the brachial artery and the outflow veins, with the largest more than 7 cm in diameter. A very proximal brachial artery bifurcation and increased venous flow were noted. DUS confirmed the AVM by showing continuous flow in the axillary vein. The decision for surgical resection involved vascular surgeons, radiologists, angiologists, and anaesthetists. Treatment involved opening and excision of multiple venous aneurysms and AVMs. A short segment of the aneurysmal brachial artery was also resected and repaired with end to end anastomosis. The deep brachial artery which supplied AVMs and venous aneurysms was ligated and excision of these lesions was performed. At one year follow up, there were no complications and the revascularisation was patent. Discussion: Arterial and venous aneurysms occurring together with AVMs are rare and not well documented in the medical literature. In this case, surgical intervention, including resection with direct anastomosis of the arterial aneurysm coupled with excision of venous aneurysms and AVM, proved to be effective, as evidenced by stable post-operative outcomes after one year.

Oncovascular Surgery for Soft-Tissue Sarcomas of the Lower Limbs with Vascular Contact: Comparison of Arterial Reconstruction and Arterial Subadventitial Dissection.

BACKGROUND: Soft-tissue sarcomas represent approximately 1% of adult malignancies. When they involve the lower limbs (LLs) and come into contact with blood vessels, the therapeutic choice was historically a primary amputation. Today, radical surgical resection with wide margins of safety is the primary therapeutic option for multidisciplinary limb-salvage surgery. The aim was to compare the morbidity and mortality results of an oncologic resection of LL soft-tissue sarcomas with arterial replacement (AR) to that obtained with arterial subadventitial dissection (ASD). METHODS: All consecutive patients with arterial close contact soft-tissue sarcomas of LL were included. Two groups were formed: an AR group where AR was performed following surgical resection and an ASD group in which the artery in contact with the tumor was preserved by ASD. Fisher's exact test was used. RESULTS: Eighteen patients with a median age of 61.50 (interquartile range [IQR] 54.25-69.75) years underwent oncovascular surgery with orthopedic and vascular surgeons between August 2013 and May 2022. Sarcomas were all located in the thigh. Nine patients were enrolled in each of the 2 groups. The 6-month survival rate was 77.78% in the AR group and 100% in the ASD group (P = 0.4). In the AR group, 2 patients presented local recurrence, with a median recurrence-free time of 24.48 (IQR 14.08-34.87) months, and 2 patients presented distant metastases, with metastasis-free time of 13.45 (IQR 8.12-35.11) months. In the ASD group, no local recurrence was observed, and 2 patients presented metastases with a median metastasis-free time of 3.90 (IQR 3.18-4.61) months. Six patients in the AR group and 7 in the ASD group required surgical revision (P = 0.017). No major amputation was necessary. CONCLUSIONS: Oncovascular surgery for LL sarcomas with ASD is certainly more locally morbid perioperatively than that with AR but provides patients with better medium-term survival.

Case Report and Literature Review of Prosthetic Cardiovascular Mucormycosis.

We report a rare case of aorto-bi-iliac prosthetic allograft mucormycosis in a 57-year-old immunocompetent patient in France. Outcome was favorable after surgery and dual antifungal therapy with liposomal amphotericin B and isavuconazole. In a literature review, we identified 12 other cases of prosthetic vascular or heart valve mucormycosis; mortality rate was 38%.

Mortality and Delays of Management of Acute Mesenteric Ischemia: The Need of a Dedicated Program.

BACKGROUND: To study the mortality and delays of management of patients with acute mesenteric ischemia (AMI) admitted to the emergency department of a tertiary hospital and identify risk factors for 1-month mortality. METHODS: A single-center and retrospective study including all consecutive patients treated for AMI from January 2008 to December 2018 was conducted. Short- and medium-term survival was studied with a Kaplan-Meier analysis. Delays before diagnosis and surgical intervention were collected. To determine factors associated with mortality at 1 month postoperatively, univariate and multivariate analyzes were performed. RESULTS: The survival rate of the 67 included patients was 55.22% at 1 month and 37.31% at 1 year. In-hospital mortality was 50.74%. The average delay between admission and diagnosis was 4.83 ± 5.03 hr (95% confidence interval [CI], 3.60-6.05), and the delay between admission and surgical treatment was 10.64 ± 8.80 hr (95% CI, 8.49-12.79). The independent variables associated with an increased mortality at 1 month postoperatively in the univariate analysis were age >65 years old (odds ratio [OR] = 3.52; P = 0.046), lactate >3.31 mmol/l at admission (H0) (OR = 7.38; P < 0.001), lactate >3.32 mmol/l on day 1 (H24) (OR = 5.60; P = 0.002), creatinine >95.9 µmol/l at H0 (OR = 4.66; P = 0.004), aspartate aminotransferase (AST) >59 U/l at H0 (OR = 3.55; P = 0.017), and having hypertension as comorbidity (OR = 9.32; P = 0.040). Early curative anticoagulation (z = -2.4; P = 0.016) was an independent protective factor for mortality, and lactate >3.31 mmol/l at H0 (z = 2.62; P = 0.009) was an independent predictor factor of mortality at 1 month postoperatively in the multivariate analysis. CONCLUSION: AMI remains a serious and lethal condition with delays of surgical management remaining too long due to a lack of a dedicated therapeutic protocol allowing an early diagnosis.

Robot Assisted Laparoscopy for Median Arcuate Ligament Syndrome Relief.

Objective: To evaluate the outcomes of robot assisted laparoscopic surgery for median arcuate ligament syndrome (MALS) relief. Methods: This was a single centre and retrospective study, including all consecutive patients with symptomatic MALS treated with robot assisted laparoscopic surgery. Symptom relief and quality of life (QoL) were evaluated post-operatively. A comparison between the peak systolic velocity (PSV) of the coeliac artery (CA) measured pre-operatively and post-operatively was carried out. Results: Nine interventions were performed. No conversion to laparotomy was required. There was post-operative abdominal pain relief in eight patients and QoL was improved in seven patients. Post-operatively, the CA PSV decreased (175 (IQR 160 - 195) cm/s vs. 365 (IQR 350 - 419) cm/s; p < .001). Conclusion: MALS relief with robot assisted laparoscopy is safe and provides satisfactory outcomes in terms of symptom relief and CA compression release.

Endovascular Porcine Model of Iliocaval Venous Thrombosis.

OBJECTIVE: To develop a large animal model of iliocaval deep venous thrombosis (DVT), which enables development and evaluation of interventional management and existing imaging modalities. METHODS: The experimental protocol consisted of a total endovascular approach. Pigs were percutaneously accessed through the right internal jugular and bilateral femoral veins. Three balloon catheters were inflated to induce venous stasis in the infrarenal inferior vena cava (IVC) and bilateral common iliac veins (CIVs). Hypercoagulability was induced by injecting 10 000 IU of thrombin. After 2.5 hours, the balloon catheters were removed before animal recovery. After seven, 14, 21, 28, or 35 days, animals were euthanised; the IVC and CIV were harvested en bloc, cross sectioned and prepared for histological examination. Multimodal imaging was performed before and after thrombus creation, and before animal euthanasia. RESULTS: Thirteen female domestic pigs with a mean weight of 59.3 kilograms were used. The mean maximum IVC diameter and area were 16.4 mm and 1.2 cm2, respectively. The procedure was successful in 12 animals with occlusive venous thrombosis in the region of interest on immediate post-operative magnetic resonance venography and a mean thrombus volume of 19.8 cm3. Clinical pathology results showed platelet consumption, D dimer increase, and inflammatory response. Histological evaluation demonstrated a red cell, fibrin, and platelet rich thrombus on day 1, with progressive inflammatory cell infiltration from day 7. Collagen deposition appeared in week 2 and neovascularisation in week 3. CONCLUSION: Endovascular occlusion combined with thrombin infusion is a reliable minimally invasive approach to produce acute and subacute DVT in a large animal model.

Critical Review of Large Animal Models for Central Deep Venous Thrombosis.

OBJECTIVE: To review the existing literature on large animal models of central venous thrombosis (CVT) and to evaluate its relevance in regard to the development and testing of dedicated therapeutics applicable to humans. METHODS: A systematic literature search was conducted in PubMed and Embase. Articles describing an in vivo experimental protocol of CVT in large animals, involving the iliac vein and/or the vena cava and/or the brachiocephalic vein, were included. The primary aim of the study, animal characteristics, experimental protocol, and thrombus evaluation were recorded. RESULTS: Thirty-eight papers describing more than 30 different protocols were included. Animals used were pigs (53%), dogs (21%), monkeys (24%), and cattle (3%). The median number of animals per study was 12. Animal sex, strain, and weight were missing in 18 studies (47%), seven studies (18%), and eight studies (21%), respectively. CVT was always induced by venous stasis: solely (55%), or in addition to hypercoagulability (37%) or endothelial damage (10%). The size of the vessel used for thrombus creation was measured in four studies (10%). Unexpected animal death occurred in nine studies (24%), ranging from 3% to 37% of the animals. Twenty-two studies (58%) in the acute phase and 31 studies in the chronic phase (82%) evaluated the presence or absence of the thrombus created, and its occlusive characteristic was reported, respectively, in five and 17 studies. Histological examination was performed in 24 studies (63%) with comparison to human thrombus in one study. CONCLUSION: This review showed advantages and weaknesses of the existing large animal models of CVT. Future models should insist on more rigour and consistency in reporting animal characteristics, as well as evaluating and comparing the thrombus created to human thrombus.

Explanted Vascular and Endovascular Graft Analysis: Where Do We Stand and What Should We Do?

OBJECTIVE/BACKGROUND: Since the late 1950s, major advances in vascular surgical practice have been closely associated with the introduction of novel vascular implants. These devices have been constructed from a variety of materials and have been designed to be implanted in several different ways. Despite a rigorous regulatory process, regular failures continue to be observed. A systematic review of the literature and of the Geprovas registry was performed in order to improve understanding of the failures. METHODS: A systematic review was performed via a search of the MEDLINE and Embase databases. Full text, English, German, or French language studies without any chronological limit were included. The reference lists of included studies, as well as the first 20 related items, were scanned for other potentially relevant studies. RESULTS: Data extraction allowed the evaluation of 184 publications; 72 publications met the inclusion criteria. Only 12 publications reported sufficient data for structural, histopathological, and epidemiological analysis. However, explant analysis allowed the understanding of degenerative phenomena: "warp knitted" replaced "weft knitted" polyethylene terephthalate grafts, decreasing the risk of dilatation or rupture; inter-nodal distance was modified in order to improve polytetrafluoroethylene graft incorporation capacities; and index of saturation, endograft fabric/stent interactions, and stent fatigue phenomena have been extensively studied in an attempt to improve endovascular device durability. CONCLUSION: A general lack of depth of reporting of explants remains. Dedicated systematic explant analysis programs are the key to improving the performance of future generations of devices.