Treatment of an Infected, Bovine Pericardial Carotid Patch: Excision and Reconstruction with a Superficial Femoral Arterial Interposition Graft

Open Surgical Conversion of Popliteal Endograft Infection: Case Reports and Literature Review

BACKGROUND

Endovascular treatment of popliteal aneurysms (PA) has increased in the last few years, quickly becoming the main treatment performed in many vascular centers, based on the acceptable and promising outcomes reported in the literature. However, endograft infections after endovascular popliteal aneurysm repair (EPAR) are the most dangerous complications to occur as they involve serious local compromise and usually require open surgical conversion and device explantation to preserve the affected extremity.

CASE REPORT

We report two patients who were admitted to the emergency room of our hospital for pain and edema in the lower leg. Both patients had undergone exclusion of a ruptured PA a few years before by endovascular graft. CTA testing showed a significant volume of fluid-corpuscular collection related to perianeurysmal abscess collection in both cases. Blood cultures and drained material cultures were positive for Staphylococcus capitis in the first case and S. aureus in the second. Prophylactic antibiotics were administered for 10 days, then patients underwent an open surgical conversion with the complete explantation of endovascular material and a femoro-popliteal bypass using an autologous vein in the first case and a biological bovine pericardium prosthesis in the second case. The infective department of our hospital had defined a discharged specific antibiotic therapy for each patient, based on intraoperative microbiological samples. Furthermore, we have examined the literature and found six more cases described in case report articles that refer to popliteal graft infections by different microorganisms, mostly presenting acute limb ischemia as the first symptom and suggesting endograft explantation with open conversion and autologous vein bypass as the commonest therapeutic choice.

CONCLUSIONS

The open surgical conversion of popliteal endograft infection is the best strategy to manage peripheral infection after an endovascular popliteal aneurysm repair procedure.

Use of a bovine pericardial patch angioplasty for completion of a complicated end to side anastomosis of a recipient vessel in the free flap reconstruction of a radiated wound: A case report

Soft tissue sarcomas treated by extensive surgical resection and adjuvant radiation can lead to large tissue deficits that require free flap repair. Significant radiation can further compromise vessels necessitating novel therapeutic approaches. We describe an 82-year-old man who presented with a posterior thigh sarcoma and underwent wide local tumor resection and immediate reconstruction with a microvascular free flap. Due to radiated recipient vessels, this case required bovine patch angioplasty as a conduit for end to side anastomosis. Initial resection and pathology revealed a large myxofibrosarcoma. Wide local resection and radiotherapy resulted in a large irradiated soft tissue defect of 26 x 15 x 4 cm with exposed, radiation damaged neurovascular structures, and a lack of available regional flap options. The planned free flap, a 30 x 8 cm skin island from the left latissimus dorsi muscle with end-to-side anastomosis to the popliteal artery was complicated by friability of the vessel wall and insufficient perfusion. Given the extent of resection and radiation, there were no alternative recipient vessels present within the field. A bovine pericardial patch angioplasty of 2.5 cm in length was performed to the diseased popliteal vessel and an end to side anastomosis was successfully performed between the thoracodorsal artery and the patch. Improved reperfusion of the free flap was noted immediately following anastomosis indicating completion of the anastomosis of our complicated recipient vessel. During the uncomplicated postoperative course, the flap had good perfusion with Doppler signals present, and incision sites intact at discharge from acute hospitalization. Recurrent sarcomas that have undergone extensive resection and radiotherapy pose significant reconstructive challenges. For defects that require free tissue reconstruction when there are limited options for healthy, recipient vessels, bovine pericardial patch angioplasty may act as a robust conduit for diseased vessels.

Computed Tomography Angiography and B-Mode Ultrasonography under Artificial Intelligence Plaque Segmentation Algorithm in the Perforator Localization for Preparation of Free Anterolateral Femoral Flap

This research was aimed to investigate the accuracy of U-shaped network (UNet)-based computed tomography angiography (CTA) and B-mode ultrasonography (US) in the perforator localization of free anterolateral thigh flap (ALTF). Based on UNet, a fusion of deep supervision mechanism, squeeze-and-excitation module, and attention mechanism was introduced to optimize the algorithm. Then, a CTA segmentation model, DA-UNet, was established. The segmentation performance of DA-UNet and other algorithms was compared under the same conditions. 30 patients who were planned to receive ALTF surgery were selected as the research objects. According to different preoperative localization methods, they were divided into group A (CTA) and group B (B-mode US), 15 cases in each group. Combined with the actual situation during surgery, the diagnostic accordance rate, sensitivity (Sen), specificity, and the distance between the perforator location and the actual location were compared between the two groups. The Dice coefficient, Jaccard index, Sen, the area under curve (AUC), and average Hausdorff distance (AVD) of the DA-UNet segmentation algorithm were 80.70%, 69.97%, 77.56%, 0.887, and 2.48, respectively. These results were significantly better than those of other algorithms (P < 0.05). In group A, the diagnostic accordance rate, Sen, and specificity of patients were 96.55%, 90.52%, and 73.58%, respectively, which were higher than 91.53%, 81.36%, and 15.60% of patients in group B significantly (P < 0.05). There was no statistical difference in the distance between the perforator location and the actual location (P > 0.05). It showed that the accuracy of CTA under the UNet-based DA-UNet segmentation model in the perforator localization of ALTF was better than that of B-mode US. Thus, a reference could be provided for the preparation of free ALTF and its clinical application.

Ex Vivo and In Vivo Analysis of a Novel Porcine Aortic Patch for Vascular Reconstruction

(1) Background: The aim of the present study was the biocompatibility analysis of a novel xenogeneic vascular graft material (PAP) based on native collagen won from porcine aorta using the subcutaneous implantation model up to 120 days post implantationem. As a control, an already commercially available collagen-based vessel graft (XenoSure®) based on bovine pericardium was used. Another focus was to analyze the (ultra-) structure and the purification effort. (2) Methods: Established methodologies such as the histological material analysis and the conduct of the subcutaneous implantation model in Wistar rats were applied. Moreover, established methods combining histological, immunohistochemical, and histomorphometrical procedures were applied to analyze the tissue reactions to the vessel graft materials, including the induction of pro- and anti-inflammatory macrophages to test the immune response. (3) Results: The results showed that the PAP implants induced a special cellular infiltration and host tissue integration based on its three different parts based on the different layers of the donor tissue. Thereby, these material parts induced a vascularization pattern that branches to all parts of the graft and altogether a balanced immune tissue reaction in contrast to the control material. (4) Conclusions: PAP implants seemed to be advantageous in many aspects: (i) cellular infiltration and host tissue integration, (ii) vascularization pattern that branches to all parts of the graft, and (iii) balanced immune tissue reaction that can result in less scar tissue and enhanced integrative healing patterns. Moreover, the unique trans-implant vascularization can provide unprecedented anti-infection properties that can avoid material-related bacterial infections.

Carotid Endarterectomy with Stent Graft Removal and End to End Bypass in the Treatment of In-Stent Occlusion after Endovascular Therapy of Carotid Gunshot Injury

Carotid jugular fistula and pseudoaneurysm are easy to form after gunshot injury of carotid artery. Endovascular therapy, such as stent graft implantation, can successfully block the fistula and pseudoaneurysm cavity. However, the possibility of in-stent restenosis or occlusion will lead to treatment failure. The authors describe the case of a 30-year-old man with carotid jugular fistula and pseudoaneurysm after gunshot injury of left carotid artery who had received stent graft placement. However, two years after stent graft, the stenosis of proximal carotid artery near stent was found and gradually aggravated. During the follow-up, transient amaurosis of his left eye occurred intermittently and in-stent occlusion and severe stenosis of proximal carotid artery were found by computed tomography angiography (CTA) in our center. Carotid endarterectomy (CEA)with stent graft removal and end to end bypass using vascular graft was performed to reconstruct the blood flow of left carotid artery. To the extent of the authors' knowledge, this case illustrates a rare CEA and vascular graft bypass in the treatment of in-stent occlusion following the gunshot injury to the carotid artery. The successful treatment of this rare case provides an option to deal with this kind of tricky problem.