Iliac Vein Rupture During the Endovascular Treatment for May-Thurner Syndrome in a Previously Irradiated Pelvis.

May-Thurner syndrome (MTS) is a vascular condition for which endovascular management is commonly chosen. We report an unusual presentation of this syndrome in a patient with previous Wertheim hysterectomy and pelvic radiotherapy, characterized by bilateral leg swelling due to radiation-induced right iliac vein stenosis. Endovascular left iliac vein stenting was performed. During the procedure, an iliac vein rupture occurred after stenting and was successfully treated using a stent graft. Two months follow-up showed a significant reduction of the leg swelling and the patency of the iliac stents. This rare case highlights a potential major risk of iliac vein rupture during the endovascular procedure in an irradiated pelvis.

Spontaneous Pneumomediastinum: A Possible Severe Condition in SARS-CoV-2 Pneumonia.

Background Spontaneous pneumomediastinum (SP) is the presence of free air into extra-alveolar tissues within the mediastinum, without notion of trauma. This rare condition may occur as a complication of an underlying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia. Higher rates of mechanical ventilation are reported in coronavirus disease 2019 (COVID-19) patients with pneumomediastinum. Case Description We report two cases of COVID-19 infected patients suffering from mild and severe SP and their outcome. Discussion The objective of this report is to review the literature about this condition. We discuss about the pathological pathways underlying this complication and how it reflects the severity of COVID-19 pneumonia. Conclusion Currently, it remains unclear if SP in SARS-CoV-2 pneumonia is a potential predictor of disease worsening, for it does not seem to be related with a higher rate of mortality.

Enhanced Vascular Biocompatibility and Remodeling of Decellularized and Secured Xenogeneic/Allogeneic Matrices in a Porcine Model.

BACKGROUND/PURPOSE: Calcifications and absence of growth potential are the major drawbacks of glutaraldehyde-treated prosthesis. Decellularized and secured xeno-/allogeneic matrices were assessed in a preclinical porcine model for biocompatibility and vascular remodeling in comparison to glutaraldehyde-fixed bovine pericardium (GBP; control). METHODS: Native human (fascia lata, pericardium) and porcine tissues (peritoneum) were used and treated. In vitro, biopsies were performed before and after treatment to assess decellularization (hematoxylin and eosin/DAPI). In vivo, each decellularized and control tissue sample was implanted subcutaneously in 4 mini-pigs. In addition, 9 mini-pigs received a patch or a tubularized prosthesis interposition on the carotid artery or abdominal aorta of decellularized (D) human fascia lata (DHFL; n = 4), human pericardium (DHP; n = 9), porcine peritoneum (DPPt; n = 7), and control tissue (GBP: n = 3). Arteries were harvested after 1 month and subcutaneous samples after 15-30 days. Tissues were processed for hematoxylin and eosin/von Kossa staining and immunohistochemistry for CD31, alpha-smooth muscle actin, CD3, and CD68. Histomorphometry was achieved by point counting. RESULTS: A 95% decellularization was confirmed for DHP and DPPt, and to a lower degree for DHFL. In the subcutaneous protocol, CD3 infiltration was significantly higher at day 30 in GBP and DHFL, and CD68 infiltration was significantly higher for GBP (p < 0.05). In intravascular study, no deaths, aneurysms, or pseudoaneurysms were observed. Inflammatory reaction was significantly higher for DHFL and GBP (p < 0.05), while it was lower and comparable for DHP/DPPt. DHP and DPPt showed deeper recellularization, and a new arterial wall was characterized. CONCLUSIONS: In a preclinical model, DPPt and DHP offered better results than conventional commercialized GBP for biocompatibility and vascular remodeling.

Decellularized and Secured Porcine Arteries with NaOH-based Process: Proof of Concept.

BACKGROUND: There is a need for small caliber vascular prosthesis. Synthetic grafts are hindered by thrombogenicity and rapid occlusion. Decellularized matrices could be an alternative. We assessed in vitro and in vivo the biocompatibility of porcine artery treated with a chemical/physical process for decellularization and graft securitization with non/conventional pathogens inactivation. METHODS: Porcine carotid arteries (PCA) were treated. First, biopsies (n = 4/tissue) were performed before/after treatment to assess decellularization (hematoxylin and eosin/-4',6-diamidino-2-phenylindole/DNA/Miller). Second, 5 rats received an abdominal aortic patch of decellularized PCA (DPCA). Four pigs received subcutaneous DPCA implants (n = 2/pig). Half were explanted at day 15 and half at day 30. Finally, 2 pigs received DPCA (n = 2) and polytetrafluoroethylene prosthesis (n = 1), respectively, as carotid interposition. Implants were removed at day 30. Inflammation (CD3 and CD68 immunostaining) calcifications (von Kossa staining), remodeling (hematoxylin and eosin), and vascular characterization (CD31 and alpha-smooth muscle actin immunofluorescent staining) were investigated. RESULTS: Ninety-five percentage of decellularization was obtained without structural deterioration. No death occurred. Low inflammatory reaction was found in the 2 models for DPCA. Acquisition of vascular identity was confirmed in the rodent and porcine models. Similarity between native PCA and DPCA was observed after 30 days. In contrast, polytetrafluoroethylene graft showed severe calcifications, higher CD3 reaction, and higher intimal hyperplasia (P < 0.05). CONCLUSIONS: The physical and chemical process ensures decellularization of carotid porcine arteries and their in vivo remodeling with the presence of an endothelium and smooth-muscle-like cells as well as a low level of inflammatory cells.