Month: April 2026

Yonsei Med J. 2026 Apr;67(4):297-305. doi: 10.3349/ymj.2025.0174.

ABSTRACT

PURPOSE: Aortic prostheses are used in pulmonary positions due to structural similarities between the pulmonary and aortic valves. However, there are no available studies that have comprehensively evaluated the mechanism of bioprosthetic aortic valves under pulmonary conditions.

MATERIALS AND METHODS: Using a mock circulatory system, we evaluated the hydrodynamic characteristics of bovine pericardial and porcine valves. Geometric orifice area, regurgitant and leakage volume, regurgitant fraction, peak pressure gradient, and forward flow volume were evaluated in different pulmonary pressure conditions (from 15/5 mm Hg to 75/35 mm Hg) and normal aortic pressure (110/80 mm Hg).

RESULTS: Bovine pericardial valves were associated with larger opening area (0.93±0.01 vs.1.70±0.01 for 23-mm valve; 0.99±0.01 vs.1.75±0.01 for 25-mm valve; 1.58±0.01 vs. 2.25±0.02 for 27-mm valve; all p<0.01) and forward flow volume (42.27±0.05 vs. 64.79±0.14 for 23-mm valve; 46.41±0.06 vs. 64.28±0.18 for 25-mm valve; 72.64±0.17 vs.73.25±0.07 for 27-mm valve; all p<0.01). Porcine valves were associated with incomplete opening, smaller opening area, and lower regurgitant fraction. Bovine pericardial valves demonstrated lower peak pressure gradients (15.75±0.14 vs. 12.57±0.47 for 23-mm valve; 14.85±0.05 vs. 12.87±0.28 for 25-mm valve; 15.72±0.32 vs. 7.91±0.03 for 27-mm valve).

CONCLUSION: Bovine pericardial and porcine bioprosthetic valves has different hydrodynamic characteristics under various pulmonary pressure conditions.

PMID:41914313 | PMC:PMC13040176 | DOI:10.3349/ymj.2025.0174

J Vasc Access. 2026 Mar 11:11297298261424940. doi: 10.1177/11297298261424940. Online ahead of print.

ABSTRACT

BACKGROUND: Native arteriovenous fistulas remain the preferred vascular access for hemodialysis. However, critically unfavorable venous anatomy can impede their successful creation. Poor-quality or small-sized distal veins with areas of focal stenosis and thickened venous segments compromise the feasibility of placing a standard arteriovenous fistula or lead to fistula nonmaturation or malfunction, requiring adjuncts such as primary angioplasty or staged-balloon assisted maturation.

METHODS: This is a report of a single-stage technique using a short strip of bovine pericardium, tapered at the venous half of the patch in a “boat-shaped” configuration and flared at the arterial half of the patch, which is tubularized to create a cylindrical conduit and bridge an otherwise healthy vein with a focal stenosis to the target artery. With this onlay-tubularized bovine pericardial patch, the diseased segment can be enlarged and a smooth “neovein” created while preserving the autogenous cannulation segment.

RESULTS: The technique is illustrated in the case of a 56-year-old patient with immunoglobulin A nephropathy and a distal basilic vein focal defect. Immediate postoperative results were positive with strong bruit and thrill while follow-up duplex within 2 months showed excellent venous dilation and a flow exceeding 600 mL/min. Patency at 12 months remains intact.

CONCLUSIONS: It is appropriate to use this technique in patients with adequate inflow and outflow, but with focal vein stenoses or short, thickened vein segments that preclude the use of a standard AVF. This hybrid approach, combining principles of patch venoplasty and bovine pericardial bypass grafting, may be used as a salvage option in selected patients with focal venous stenotic lesions considered for native arteriovenous fistula creation.

PMID:41810476 | DOI:10.1177/11297298261424940

Angiogenesis. 2026 Mar 8;29(2):22. doi: 10.1007/s10456-026-10039-7.

ABSTRACT

BACKGROUND: Exploring the hemocompatibility of bioprosthetic heart valves (BHVs) has been challenging due to the scarcity of non-degenerated material.

OBJECTIVES: This study has two complementary objectives (1) To characterize the extent and temporal kinetics of endothelial coverage of BHVs implanted in humans; (2) To investigate, in a rat model, the impact of pericardial endothelialization on tissue calcification.

METHODS: We employed histology and electron microscopy to assess cellular organization in non-degenerated BHVs and conducted hemodynamic simulations to evaluate shear stress fields in the ejection valves area. Furthermore, we investigated the impact of pericardium endothelial coverage on calcification using endothelial colony-forming cells (ECFCs) cultured on bovine pericardium discs implanted in athymic nude rats for 18 days. Calcium content was quantified through acetylene flame atomic absorption spectrophotometry.

RESULTS: We observed inflammatory cell infiltration within all explanted BHVs, as well as fibrin deposit on top of the leaflets. Endothelial coverage emerged in long-term implants (> 180 days) but remained incomplete in aortic valves, which could be linked to high shear stress levels in aortic position confirmed in hemodynamic simulations. Besides, the rat experiments revealed that the discs covered with fibrin + ECFCs were significantly less calcified than those covered with fibrin alone (respectively, median = 0.9 µg Ca/mg tissue; IQR: 0.7–1.1 vs median = 18.3 µg Ca/mg tissue; IQR: 9–34.9; p = 0.0003), and less extensively colonized by neutrophils.

CONCLUSIONS: Human explanted BHVs showed intact leaflets with a fibrin layer and organized endothelial coverage, without detectable calcification over the short observation period. In rats, endothelialization was associated with significantly reduced pericardial calcification, suggesting a potential protective effect. However, the limited follow-up in humans precludes conclusions on a causal role of endothelial coverage in hemocompatibility or protection against calcification.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10456-026-10039-7.

PMID:41795724 | PMC:PMC12968097 | DOI:10.1007/s10456-026-10039-7

Int J Surg Case Rep. 2026 Jan 28;138(3):674-679. doi: 10.1097/RC9.0000000000000083. eCollection 2026 Mar.

ABSTRACT

INTRODUCTION: Primary aortoenteric fistulas are rare, life-threatening conditions, usually secondary to abdominal aortic aneurysms. Primary aortoduodenal fistula (PADF) without aneurysmal disease is extremely rare, with very few cases reported in the literature. Delayed diagnosis is common and contributes to high mortality.

CASE PRESENTATION: We report the case of a 71-year-old woman with high-grade serous ovarian cancer who developed a PADF in the absence of an aortic aneurysm. The patient presented with hematemesis and abdominal pain. Initial investigations, including Computed Tomography (CT) scan and upper endoscopy (EGDS), were inconclusive. Although she was initially stabilized, she experienced recurrent gastrointestinal bleeding leading to hemodynamic deterioration. Emergency CT showed active arterial hemorrhage near the duodenum. An urgent exploratory laparotomy confirmed the presence of a PADF, which was surgically repaired using a bovine pericardial patch. Despite surgical intervention, the patient succumbed to postoperative multiorgan failure.

CLINICAL DISCUSSION: PADFs most frequently involve the third or fourth portion of the duodenum and are strongly correlated with aneurysmal disease. However, rare etiologies such as radiation therapy, malignancy, or infection may precipitate fistula formation even in the absence of aneurysms. Our literature review identified only 16 similar cases reported since 2015. Diagnosis remains challenging due to non-specific symptoms and inconclusive early imaging. A high index of suspicion is essential. CT angiography is the most effective diagnostic modality. Definitive management requires urgent surgical or endovascular repair, although prognosis remains poor in hemodynamically unstable patients.

CONCLUSION: This case underscores the need to consider PADF in the differential diagnosis of gastrointestinal bleeding, even in the absence of aneurysmal disease, particularly among oncologic patients with prior radiation exposure or retroperitoneal inflammation. Early diagnosis, prompt imaging, and a multidisciplinary approach are essential to improving patient outcomes.

PMID:41837109 | PMC:PMC12981790 | DOI:10.1097/RC9.0000000000000083

J Vitreoretin Dis. 2026 Feb 25:24741264261423306. doi: 10.1177/24741264261423306. Online ahead of print.

ABSTRACT

Purpose: To evaluate the efficacy and safety of bovine pericardium (Tutopatch) to seal peripheral retinal breaks located over areas of chorioretinal atrophy in highly myopic eyes. Methods: Highly myopic patients with retinal detachment (RD) caused by retinal breaks over areas of chorioretinal atrophy underwent 25-gauge pars plana vitrectomy, subretinal fluid drainage, and silicone oil (SO) tamponade. A trimmed Tutopatch was placed over the retinal breaks. Follow-up assessments were performed over 12 months, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), fundus photography, and widefield optical coherence tomography. Results: Seven eyes of highly myopic patients were included in this study. All eyes achieved complete retinal reattachment, with no recurrence of detachment after SO removal. The median BCVA improved from 0.10 (20/200 Snellen) preoperatively to 0.20 (20/100 Snellen) postoperatively. In addition, the mean IOP increased preoperatively from 13.0 ± 2.6 mm Hg to 15.0 ± 4.2 mm Hg postoperatively. The Tutopatch remained adherent to the retina throughout follow-up, without signs of inflammation, epiretinal membrane formation, or other complications. Conclusions: Tutopatch appears to be a safe and effective method for sealing retinal breaks in areas of chorioretinal atrophy in which conventional treatments are not available. This technique may help prevent redetachment in highly myopic eyes. Larger studies are warranted to confirm our findings.

PMID:41767762 | PMC:PMC12945725 | DOI:10.1177/24741264261423306

Clin Adv Periodontics. 2026 Feb 28. doi: 10.1002/cap.70046. Online ahead of print.

ABSTRACT

BACKGROUND: Autogenous particulate dentin has emerged as one of the promising biocompatible alternatives to traditional bone graft materials in alveolar ridge augmentation. Although its clinical success is documented, comprehensive studies combining histological and radiographic evaluations remain limited. This case report addresses this gap by detailing a novel approach using autogenous particulate dentin combined with cancellous allograft and a long-lasting absorbable barrier membrane (lasso-guided bone regeneration technique) for horizontal ridge augmentation.

METHODS AND RESULTS: A 49-year-old female presented with insufficient alveolar ridge width (Seibert Class I) at edentulous sites #12 and #14, necessitating bone augmentation before implant placement. The procedure involved a layered approach: Cancellous allograft (internal layer, faster remodeling) followed by autogenous particulate dentin (outer layer, slower remodeling). A bovine pericardium membrane was used to isolate the graft site and promote healing. Six months post-surgery, cone-beam computed tomography scans demonstrated significant alveolar ridge width gains of 4.64 mm at #12 and 4.21 mm at #14. Implants were successfully placed, and a bone core harvested at the 4-month mark confirmed the slow remodeling rate of the dentin particles compared to the allograft. One year post-restoration, the implants remain functional.

CONCLUSION: This case report highlights the efficacy of the layered approach using autogenous particulate dentin, particularly for space maintenance. The slower remodeling rate of dentin suggests its suitability as an outer layer, enhancing long-term stability. This innovative technique and material selection may represent a significant advancement in alveolar ridge augmentation procedures. Further studies are warranted to confirm these findings and determine optimal applications in the long term.

KEY POINTS: The case demonstrates that a biologically driven layered grafting approach-placing cancellous allograft internally for faster remodeling and autogenous particulate dentin externally for slower turnover and superior space maintenance-is an option to perform horizontal ridge augmentation by mimicking natural bone architecture. Histologic findings highlight that dentin particles remodel very slowly yet remain well integrated within the grafted site without complications, contributing to stability while allowing substantial formation of vital bone. This confirms that autogenous dentin serves as a reliable, long-lasting scaffold that supports new bone formation. However, long-term evaluation may still be necessary. The use of a long-lasting absorbable pericardium membrane stabilized with the lasso GBR technique ensures membrane security, space preservation, and tension-free primary closure-factors that collectively promote predictable healing and successful guided bone regeneration consistent with biology.

PLAIN LANGUAGE SUMMARY: This case report presents a new approach for rebuilding bone in the jaw to allow for dental implant placement. A 49-year-old woman had insufficient bone width in the upper jaw, which made implant treatment impossible without bone augmentation. To solve this, the treatment combined two materials: donated human bone on the inside, which remodels quickly, and the patient’s own tooth material, ground into small particles, on the outside, which remodels more slowly and helps maintain space. A protective membrane was used to stabilize the graft and promote healing. After 6 months, 3D scans showed a significant increase in bone width, allowing implants to be placed successfully. A small bone sample confirmed the slow remodeling of the tooth particles compared with the donated bone. One year after the final restoration, the implants remained functional and stable. This technique suggests that using a patient’s own tooth material, combined with other grafting materials, may provide a safe and effective alternative for jawbone reconstruction. It may also reduce the need for animal-derived products while improving long-term stability for implant treatments.

PMID:41761954 | DOI:10.1002/cap.70046

J Clin Med. 2026 Feb 8;15(4):1336. doi: 10.3390/jcm15041336.

ABSTRACT

Background/Objectives: Entelon150^® (Vitis vinifera seed extract), losartan, and rosuvastatin have been shown to be effective in reducing calcification and inflammation of bovine pericardium implants. However, no study has compared the effects of the drugs on bioprosthetic heart valve (BHV). This study aimed to compare the anti-calcification and anti-inflammatory effects of each drug in a rat model. Methods: Twenty-eight female Sprague-Dawley rats (two weeks old) were implanted with BHV leaflets in the dorsal subcutis. They were divided into control, losartan (10.3 mg/kg/day), rosuvastatin (2 mg/kg/day), and Entelon150^® (30.8 mg/kg/day) groups. Eight weeks later, the calcium level and inflammatory cell infiltration in the BHV leaflets as well as the expression levels of IL-6, osteopontin, and BMP-2 in the surrounding tissues were measured. Results: Losartan-, Entelon150^®-, and rosuvastatin-treated groups showed a decrease in the calcium content as compared to the control group in the order. A reduction in the inflammatory cell infiltration was observed in the treatment groups (losartan > Entelon150^® > rosuvastatin) as compared to that in the control group. The treatment groups showed a decrease in IL-6, OPN, and BMP-2 expression levels as compared to the control group in the following order: Entelon150^® > losartan > rosuvastatin. Conclusions: The calcification of the BHV leaflets and inflammation of the surrounding tissues in treatment groups were lower than those in the control group and were comparable to each other. Entelon150^® showed comparable anti-inflammatory and anti-calcification effects and may represent a potential therapeutic candidate for prolonging BHV durability, although further validation is required.

PMID:41753024 | PMC:PMC12941210 | DOI:10.3390/jcm15041336

Cureus. 2026 Jan 11;18(1):e101321. doi: 10.7759/cureus.101321. eCollection 2026 Jan.

ABSTRACT

Carotid artery stenting (CAS) is a well-established alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis, particularly in patients at high surgical risk. However, in-stent restenosis (ISR) remains a notable long-term complication, occurring in up to 20% of patients within five years. The optimal management strategy for ISR remains unclear, as endovascular reintervention carries a significant risk of recurrence, and evidence supporting surgical explantation is limited. We present two patients who developed severe carotid ISR and were successfully treated with CEA and complete stent explantation followed by bovine pericardial patch angioplasty. The first patient, an 84-year-old woman with bilateral carotid disease and a history of left carotid stenting, developed 90% restenosis at surveillance and underwent staged bilateral carotid revascularization with durable patency at three-year follow-up. The second patient, a 70-year-old man, presented with acute visual loss and imaging demonstrating near-occlusive thrombosis within a previously placed carotid stent. He underwent urgent surgical stent removal and patch angioplasty, achieving full recovery and maintaining patency at one year. Neither patient experienced perioperative neurological or cardiovascular complications. These cases highlight the feasibility and safety of surgical stent explantation in the management of carotid ISR. Compared with repeat endovascular interventions, surgical removal directly addresses the underlying mechanical and neointimal causes of restenosis and may provide superior long-term durability in appropriately selected patients. CEA with stent explantation represents an effective treatment option for ISR, particularly when endovascular options are limited by calcification, thrombus, or mechanical failure. Larger prospective studies are needed to establish patient selection criteria and optimize management strategies for this challenging clinical scenario.

PMID:41694952 | PMC:PMC12894099 | DOI:10.7759/cureus.101321

Gels. 2026 Jan 28;12(2):118. doi: 10.3390/gels12020118.

ABSTRACT

The physiological relevance of in vitro models is limited because conventional two-dimensional cell culture systems are unable to replicate the structural and functional complexity of native tissues. Extracellular matrix (ECM)-mimetic hydrogels have become important platforms for tissue engineering applications. This work developed hybrid hydrogels that mimic important biochemical and mechanical characteristics of cardiac tissue by combining decellularized bovine pericardium-derived (dBP) ECM, gellan gum (GG), and spermine (SPM). Although dBP offers tissue-specific biological cues, processing compromises its mechanical integrity. This limitation was overcome by adding GG, whose ionic gelation properties were optimized using DMEM and SPM. The hydrogels’ mechanical, biological, physicochemical, and structural characteristics were all evaluated. Under physiologically simulated conditions, the formulations showed quick gelation and long-term stability; scanning electron microscopy revealed an interconnected, ECM-like porous microarchitecture. While uniaxial compression testing provided Young’s modulus values comparable to native myocardium, rheological analysis revealed a concentration-dependent increase in storage modulus with increasing SPM content. H9C2 cardiomyoblasts were used in cytocompatibility studies to confirm that cell viability, morphology, and cytoskeletal organization were all preserved. All of these findings support the potential application of dBP-GG-SPM hydrogels in advanced in vitro cardiac models by showing that they successfully replicate important characteristics of cardiac ECM.

PMID:41744990 | PMC:PMC12939898 | DOI:10.3390/gels12020118

Ann Surg Oncol. 2026 Feb 12. doi: 10.1245/s10434-026-19228-6. Online ahead of print.

ABSTRACT

BACKGROUND: In this video demonstration, we highlight the robotic-assisted resection of a left retroperitoneal leiomyosarcoma and reconstruction of the left renal vein with a bovine pericardial patch.

PATIENT AND METHODS: The patient was placed supine on a split leg table, in 20 degrees of Trendelenburg. After the DaVinci Xi robot was docked, the posterior peritoneum was incised, lifting the right colon and cecum off the retroperitoneum. The peritoneum was temporarily tethered to the anterior abdominal wall using holding stitches. The right gonadal vein was identified and dissected into its insertion into the inferior vena cava (IVC). The IVC was skeletonized to identify the left renal vein. The left renal vein sarcoma was identified and circumferentially dissected. The left renal artery was clamped and proximal and distal control was obtained on the left renal vein. The anterior aspect of the left renal vein was excised en bloc with the sarcoma, with a margin of normal healthy appearing renal vein tissue. Using a 3 × 2 cm bovine pericardial patch, left renal vein reconstruction was performed using running 5-0 Goretex suture. Warm ischemia time was 35 min. The specimen was extracted through a lower midline incision.

RESULTS: The patient was discharged on postoperative day 2 after uneventful hospital course. Her renal function remained unchanged after surgery. Pathology confirmed grade 1 leiomyosarcoma with negative surgical margins.

CONCLUSIONS: With the use of the surgical robot, we demonstrate complete resection of a leiomyosarcoma with reconstruction of the left renal vein to allow preservation of renal function.

PMID:41678049 | DOI:10.1245/s10434-026-19228-6