Superior vena cava reconstruction using bovine jugular vein conduit

Superior Vena Cava Resection in Locally Advanced Thymoma-Surgical and Survival Outcomes

This study was aimed at reporting the surgical management of superior vena cava invasion in patients with locally advanced thymoma and to evaluate surgical and survival outcomes. This is a retrospective analysis of 12 patients operated for superior vena cava resection for locally advanced thymoma over 8 years in a thoracic surgery centre in India. An analysis of peri-operative variables including complications was carried out. The influence of various predictors on survival was assessed by log-rank test. Intra-operatively, superior vena cava (SVC) alone was involved in 3 (25%) cases, SVC with BCV involvement was there in 8 cases (66.7%) and in 1 patient, the SVC involvement extended into the right atrium also. In all cases, the tumour was resected en bloc with the involved part of SVC. Repair with primary closure was sufficient in 2 cases (16.6%) in view of < 1/3rd of circumferential involvement. However, in remaining 10 cases, SVC was replaced with PTFE graft (single graft in 6 cases, Y-graft in 2 cases and twin grafts in 2 cases). No peri-operative deaths. Overall survival (OS) at 1, 3 and 5 years was 100%, 91.6% and 83.3%, respectively. Myasthenia gravis and higher Masaoka stage (IV A) of the disease were poor predictors of survival. Superior vena cava resection and reconstruction is a feasible and oncologically superior option in invasive thymoma with SVC involvement. This challenging surgical procedure should only be attempted by an experienced team of thoracic and cardiac surgeons at high-volume centre to achieve best outcomes.

Prosthetic Reconstruction of Superior Vena Cava System for Thymic Tumor: A Retrospective Analysis of 22 Cases

OBJECTIVE

This study aimed to report our experience in superior vena cava (SVC) resection and reconstruction for 22 thymic tumor patients and to make comparisons with previous related reports.

METHODS

A retrospective study on 22 patients (15 thymomas, 7 thymic cancers) who underwent tumor resection with concomitant SVC reconstruction. All the patients underwent vascular conduit reconstruction by the cross-clamping technique. The corresponding data were reviewed, including clinical presentation, operation management (surgery procedure, selection of suitable graft, strategies against SVC syndrome, etc.), postoperative cares (antithrombotic agent application, treatments on brain edema, etc.), and follow-up information.

RESULT

Two patients were myasthenic, well controlled by oral pyridostigmine. All resections were radical (R0). Ten patients received induction treatment. All the 15 thymoma patients were Masaoka stage III (type B1-B3). As for thymic cancer, six patients were Masaoka stage III and one was stage IVa. Wedge pulmonary resection was performed in three patients (two right upper lobe, one both upper lobe). Procedures included were single graft replacement in 12 patients, bilateral grafts in 9, and Y-shaped graft in 1 patient. Anticoagulation and dehydration agents were routinely applied after operation. No perioperative mortalities were observed. Major complication rate was 9.1%. The median survival time was 44.2 months (range, 4-92 months). Three- and 5-year overall survival rates were 80.8 and 44.0%, respectively. As for conduit patency, two grafts (9.1%) demonstrated evidence of occlusion during long-term follow-up, but no additional interventions were required due to no complications related.

CONCLUSION

Our study, confirming data from existing literature, showed that the prosthetic reconstruction of the SVC system is a feasible additional procedure during resection of thymic tumor infiltrating the venous mediastinal axis, minimally increasing postoperative complications in experienced hands.

A Case Report of Reconstruction of the Left Superior Vena Cava Using the Right Superior Vena Cava Autograft at Bilateral Bidirectional Superior Cavopulmonary Anastomosis

The choice of graft material for reconstruction of the vena cava in pediatric patients remains controversial. We successfully treated an eight-month-old female patient with single ventricle physiology and long segment obstruction of the left superior vena cava using the right superior vena cava autograft at the time of bilateral bidirectional superior cavopulmonary anastomosis. Postoperative computed tomography confirmed the patency of the reconstruction.

Reconstruction of mediastinal vessels for invasive thymoma: a retrospective analysis of 25 cases

BACKGROUND

Discuss an appropriate strategy for treatment of invasive thymoma invading adjacent great vessels.

METHODS

A retrospective study on 25 patients with invasive thymoma invading neighboring great vessels was performed. The corresponding data including clinical presentation, operation procedure, adjuvant radio-chemotherapy and follow-up were reviewed.

RESULTS

Twenty of 25 (80%) patients with invasive thymoma underwent complete resection of the tumor along with vessel reconstruction. Intraoperatively, different types of operation were conducted, namely, brachiocephalic vein (BCV)-right atrial appendage (RAA) reconstruction in 11 cases, complex vessel reconstruction (more than one graft) in 1 case and superior vena cava (SVC)-SVC reconstruction in the remaining cases. Ringed polytetrafluoroethylene (PTFE) grafts were used for vessel reconstruction. Postoperatively, three cases suffered from pulmonary infection, and three cases had haemothorax, chylothorax and atelectasis, respectively. Two patients died due to acute respiratory distress syndrome within 90 days after the surgery. Within the remaining patients, 11 cases (44%) experienced a relapse and finally 8 (32%) patients died. Compared to R1 resection group, R0 resection group had a better prognosis (Log-rank P=0.0196). The 3- and 5-year survival rates were 79.6% and 59.1%, with median survival time of 84 months.

CONCLUSIONS

Reconstruction of mediastinal vessels for invasive thymoma is a feasible technology method. Radical resection of the tumor with involved neighboring structures is the key to prolong overall survival for patients suffered from invasive thymoma.

Surgical treatment of an invasive thymoma extending into the superior vena cava and right atrium

Although invasive thymoma commonly infiltrates neighbouring mediastinal structures, its extension into the superior vena cava (SVC) and consequent SVC occlusion are rare. In such cases, the urgent removal of the thymoma and radical resection of the infiltrated SVC representreasonable options, since induction therapy is time-consuming and useless for symptom resolution. A case of invasive thymoma extending into the SVC and right atrium (RA) with SVC syndrome is reported. The patient underwent a combined resection of the invasive tumor and SVC under cardiopulmonary bypass (CPB), and the SVC and bilateral brachiocephalic vein (BCV) were reconstructed with an autologous pericardial ‘Y’ conduit. After 40 months of follow-up, the patient showed a patent graft and no tumor recurrence.

Heparin nanomodification improves biocompatibility and biomechanical stability of decellularized vascular scaffolds

Biocompatibility and biomechanical stability are two of the main obstacles limiting the effectiveness of vascular scaffolds. To improve the biomechanical stability and biocompatibility of these scaffolds, we created a heparin-nanomodified acellular bovine jugular vein scaffold by alternating linkage of heparin and dihydroxy-iron via self-assembly. Features of the scaffold were evaluated in vitro and in vivo. Heparin was firmly linked to and formed nanoscale coatings around the fibers of the scaffold, and the amount of heparin linked was about 808 ± 86 μg/cm² (101 ± 11 USP/cm²) per assembly cycle. The scaffolds showed significantly strengthened biomechanical stability with sustained release of heparin for several weeks in vitro. Importantly, the modified scaffolds showed significantly reduced platelet adhesion, stimulated proliferation of endothelial cells in vitro, and reduced calcification in a subcutaneous implantation rat model in vivo. Heparin nanomodification improves the biocompatibility and biomechanical stability of vascular scaffolds.

Controlled release of chitosan/heparin nanoparticle-delivered VEGF enhances regeneration of decellularized tissue-engineered scaffolds

Regeneration deficiency is one of the main obstacles limiting the effectiveness of tissue-engineered scaffolds. To develop scaffolds that are capable of accelerating regeneration, we created a heparin/chitosan nanoparticle-immobilized decellularized bovine jugular vein scaffold to increase the loading capacity and allow for controlled release of vascular endothelial growth factor (VEGF). The vascularization of the scaffold was evaluated in vitro and in vivo. The functional nanoparticles were prepared by physical self-assembly with a diameter of 67–132 nm, positive charge, and a zeta potential of ∼30 mV and then the nanoparticles were successfully immobilized to the nanofibers of scaffolds by ethylcarbodiimide hydrochloride/hydroxysulfosuccinimide modification. The scaffolds immobilized with heparin/chitosan nanoparticles exhibited highly effective localization and sustained release of VEGF for several weeks in vitro. This modified scaffold significantly stimulated endothelial cells’ proliferation in vitro. Importantly, utilization of heparin/chitosan nanoparticles to localize VEGF significantly increased fibroblast infiltration, extracellular matrix production, and accelerated vascularization in mouse subcutaneous implantation model in vivo. This study provided a novel and promising system for accelerated regeneration of tissue-engineering scaffolds.

Radical resection of the superior vena cava using the Contegra bovine jugular vein conduit

Radical resection of the superior vena cava poses a challenge for the cardiothoracic surgeon. The Contegra graft (Medtronic Inc, Minneapolis, MN), a biologic conduit comprising the valved segment of the bovine jugular vein, is established as a right ventricular to pulmonary artery conduit for right ventricular outflow tract repair in the pediatric population. We describe the use of the Contegra graft to facilitate radical resection and reconstruction of the superior vena cava in 2 patients, with demonstrable patency of grafts at 12 months and 7 months postoperatively.