Cryopreserved arterial allograft reconstruction after excision of thoracic malignancies

The oncologic efficacy of extended resections for lung cancer

Extended lung resections for T3-T4 non-small-cell lung cancer remain challenging. Multimodal management is mandatory in multidisciplinary tumor boards, and here the determination of resectability is key. Long-term oncologic efficacy depends mostly on complete resection (R0) and the extent of N2 disease. The development of novel innovative treatments (targeted therapy and immune checkpoint inhibitors) sets interesting perspectives to reinforce current therapeutic options in the induction and adjuvant setting.

Superior vena cava graft infection in thoracic surgery: a retrospective study of the French EPITHOR database

 

OBJECTIVES

To report our experience on the management of superior vena cava graft infection.

METHODS

Between 2001 and 2018, patients with superior vena cava synthetic graft or patch reconstruction after resection of intrathoracic tumours or benign disease were selected retrospectively from the French EPITHOR database and participating thoracic centres. Our study population includes patients with superior vena cava graft infection, defined according to the MAGIC consensus. Superior vena cava synthetic grafts in an empyema or mediastinitis were considered as infected.

RESULTS

Of 111 eligible patients, superior vena cava graft infection occurred in 12 (11.9%) patients with a polytetrafluoroethylene graft secondary to contiguous contamination. Management consisted of either conservative treatment with chest tube drainage and antibiotics (n = 3) or a surgical graft-sparing strategy (n = 9). Recurrence of infection appears in 6 patients. Graft removal was performed in 2 patients among the 5 reoperated patients. The operative mortality rate was 25%.

CONCLUSIONS

Superior vena cava graft infection may develop as a surgical site infection secondary to early mediastinitis or empyema. Graft removal is not always mandatory but should be considered in late or recurrent graft infection or in infections caused by aggressive microorganisms (virulent or multidrug resistant bacteria or fungi).

Vascular homografts as bypass grafts for superior vena cava syndrome due to idiopathic fibrosing mediastinitis

Fibrosing mediastinitis can lead to superior vena cava obstruction by generating a fibroinflammatory mass in the mediastinum. Surgical caval reconstruction with conduits could be indicated for cases of unsuccessful or technically unfeasible endovascular stenting and angioplasty. The use of cryopreserved vascular homografts seems to be better than prosthetic conduits for mid- and long-term patency, as was observed in the case we have described in the present report.

Salvage resection of advanced mediastinal tumors

The surgical treatment of locally advanced mediastinal tumors invading the great vessels and other nearby structures still represent a tricky question, principally due to the technical complexity of the resective phase, the contingent need to carry out viable vascular reconstructions and, therefore, the proper management of pathophysiologic issues. Published large-number series providing oncologic outcomes of patients who have undergone extended radical surgery for invasive mediastinal masses are just a few. Furthermore, the wide variety of different histologies included in some of these studies, as well as the heterogeneity of chemo and radiation therapies employed, did not allow for the development of clear oncologic guidelines. Usually in the past, surgical resections of large masses along with the neighbouring structures were not offered to patients because of related morbidity and mortality and limited information available on the prognostic advantage for long term. However, in the last decades, advances in surgical technique and perioperative management, as well as increased oncologic experience in this field, have allowed radical exeresis in selected patients with invasive tumors requiring resections extended to the surrounding structures and complex vascular reconstructions. Such aggressive surgical treatment has been proposed in association or not with adjuvant chemo- or radiotherapy regimens, achieving encouraging oncologic results with limited morbidity and mortality in experienced institutions. Congestive heart failure or impending cardiovascular collapse due to the compression by the large mass are the most frequent immediately life-threatening problems that some of these patients can experience. In this setting, medical palliation is usually ineffective and an aggressive salvage surgical treatment may remain the only therapeutic option.

Bilateral Brachiocephalic Vein and Superior Vena Cava Reconstruction With an Aortic Allograft

Malignant thymoma can be invasive and may require radical resection. Here we present a case with phrenic nerve, right upper lobe, bilateral brachiocephalic vein, and superior vena cava involvement. Total venous reconstruction was performed with a cryopreserved aortic allograft by using the aortic root, ongoing transverse arch, and innominate arterial branch. The patient then had postoperative radiotherapy for a total of 63 Gy over 35 treatment days. Follow-up imaging demonstrated no evidence of recurrence and intermediate-term patency but with homograft calcification developing at 4 years.

Development and characterisation of a large diameter decellularised vascular allograft

The aims of this study were to develop a biological large diameter vascular graft by decellularisation of native human aorta to remove the immunogenic cells whilst retaining the essential biomechanical, and biochemical properties for the ultimate benefit of patients with infected synthetic grafts. Donor aortas (n = 6) were subjected to an adaptation of a propriety decellularisation process to remove the cells and acellularity assessed by histological analysis and extraction and quantification of total DNA. The biocompatibility of the acellular aortas was determined using standard contact cytotoxicity tests. Collagen and denatured collagen content of aortas was determined and immunohistochemistry was used to determine the presence of specific extracellular matrix proteins. Donor aortas (n = 6) were divided into two, with one half subject to decellularisation and the other half retained as native tissue. The native and decellularised aorta sections were then subject to uniaxial tensile testing to failure [axial and circumferential directions] and suture retention testing. The data was compared using a paired t-test. Histological evaluation showed an absence of cells in the treated aortas and retention of histoarchitecture including elastin content. The decellularised aortas had less than 15 ng mg-1 total DNA per dry weight (mean 94% reduction) and were biocompatible as determined by in vitro contact cytotoxicity tests. There were no gross changes in the histoarchitecture [elastin and collagen matrix] of the acellular aortas compared to native controls. The decellularisation process also reduced calcium deposits within the tissue. The uniaxial tensile and suture retention testing revealed no significant differences in the material properties (p > 0.05) of decellularised aorta. The decellularisation procedure resulted in minimal changes to the biological and biomechanical properties of the donor aortas. Acellular donor aorta has excellent potential for use as a large diameter vascular graft.

Primary pulmonary artery sarcoma: a close associate of pulmonary embolism-20-year observational analysis

BACKGROUND

Primary pulmonary artery sarcoma (PPAS) is a rare tumor that mimics pulmonary thromboembolism (PE). Similarities to PE can delay the diagnosis and misguide the treatment of PPAS. This study aimed to evaluate tumor characteristics and outcome predictors among those diagnosed with PPAS and misdiagnosed as PE.

METHODS

From 1991-2010, 10 PPAS cases were available from the Cleveland Clinic (CC) institutional database and another 381 cases were reported in the literature. Patient characteristics, tumor subtypes, diagnostic testing & timing, interventions and clinical outcomes were analyzed. We also noted effects of misdiagnosis as PE and clinical outcome as a result of inappropriate intervention.

RESULTS

Among 391 confirmed cases of PPAS, the mean age at diagnosis was 52±14 years; 55% were male. The median duration of symptoms prior to diagnosis was 100 [interquartile range (IQR), 30-210] days. Nearly half (47%) of PPAS were originally misdiagnosed as PE including 39% that received thrombolytic and/or anticoagulation therapy. For every doubling of time from symptom onset to diagnosis, the odds of death increased by 46% (OR: 1.46, 95% CI: 1.21-1.82; P<0.001). The odds of death (OR: 2.66, 95% CI: 1.58-4.54; P=0.0003) and occurrence of distant metastasis (OR: 2.30, 95% CI: 1.30-4.15; P=0.049) were increased among those who did not receive chemotherapy but chemotherapy did not impact local recurrence. Those with complete resection had a better survival.

CONCLUSIONS

PPAS has a radiological appearance similar to PE, which makes accurate and timely diagnosis challenging. More rapid diagnosis may lead to earlier, appropriate surgical treatment and improved outcomes, when combined with adjuvant treatment.

Lyophilized allografts without pre-treatment with glutaraldehyde are more suitable than cryopreserved allografts for pulmonary artery reconstruction

Various methods are available for preservation of vascular grafts for pulmonary artery (PA) replacement. Lyophilization and cryopreservation reduce antigenicity and prevent thrombosis and calcification in vascular grafts, so both methods can be used to obtain vascular bioprostheses. We evaluated the hemodynamic, gasometric, imaging, and macroscopic and microscopic findings produced by PA reconstruction with lyophilized (LyoPA) grafts and cryopreserved (CryoPA) grafts in dogs. Eighteen healthy crossbred adult dogs of both sexes weighing between 18 and 20 kg were used and divided into three groups of six: group I, PA section and reanastomosis; group II, PA resection and reconstruction with LyoPA allograft; group III, PA resection and reconstruction with CryoPA allograft. Dogs were evaluated 4 weeks after surgery, and the status of the graft and vascular anastomosis were examined macroscopically and microscopically. No clinical, radiologic, or blood-gas abnormalities were observed during the study. The mean pulmonary artery pressure (MPAP) in group III increased significantly at the end of the study compared with baseline (P=0.02) and final [P=0.007, two-way repeat-measures analysis of variance (RM ANOVA)] values. Pulmonary vascular resistance of groups II and III increased immediately after reperfusion and also at the end of the study compared to baseline. The increase shown by group III vs group I was significant only if compared with after surgery and study end (P=0.016 and P=0.005, respectively, two-way RM ANOVA). Microscopically, permeability was reduced by ≤75% in group III. In conclusion, substitution of PAs with LyoPA grafts is technically feasible and clinically promising.

Human aortic allograft: an excellent conduit choice for superior vena cava reconstruction

Superior vena cava (SVC) reconstruction is occasionally required in the treatment of benign and malignant conditions. We report a patient with symptomatic SVC obstruction secondary to mediastinal fibrosis successfully reconstructed with an aortic allograft.

Presensitization revisited: pitfalls of vascular allografts in transplant candidates

Vascular allografts in end-stage renal disease (ESRD) patients represent a particular immunological challenge. A broad HLA immunization led us to study in depth the history of two patients with vascular allografts. In Case 1 the allograft was added to a Gore-Tex graft used for haemodialysis access and no immunosuppression was administered. In Case 2 the allograft was used to prolong a renal artery from living donor and immunosuppression was suboptimal. In vascular surgery, immunosuppression is mainly used to improve graft patency. ESRD patients are potential organ recipients and immunosuppression should therefore be tailored to reduce HLA immunization.

Pulmonary sleeve resection in locally advanced lung cancer using cryopreserved allograft for pulmonary artery replacement

BACKGROUND

During lobectomy, resection of pulmonary artery, followed by reconstruction or replacement with or without concomitant sleeve bronchial resection, is feasible in selected cases. We report morbidity, mortality, and technical issues in pulmonary artery replacement using a cryopreserved arterial allograft after sleeve resection for centrally located non-small cell lung carcinoma (NSCLC).

METHODS

We reviewed clinical and pathologic data of patients who underwent arterial sleeve lobectomy with pulmonary artery replacement in our institution from 2007 to 2012.

RESULTS

Of 178 centrally located NSCLCs, sleeve resections were performed in 92 (51%), pneumonectomies in 33 (18%), and lobectomies in 53 (31%). Of the 32 (34.7%) pulmonary) reconstructions (excluding tangential suture), 20 (21.7%) were end-to-end anastomosis, 2 (2.1%) were pericardial patch reconstructions, and 10 (11%) were PA replacements. Clinical T staging was cT2a in 4 patients, cT2b in 3, cT3 in 2, and cT4 in 1. Four patients received concurrent induction chemoradiotherapy. Three patients underwent a double-sleeve right lobectomy. Cryopreserved allografts used were descending thoracic aorta (n = 3) and pulmonary arteries (n = 7). Complete resection (R0) was achieved in all patients. Final N staging was pN0 (n = 4), pN1 (n = 5), and pN2 (n = 1). There was no operative mortality. Four patients had major morbidity, including 1 early conduit thrombosis treated by pneumonectomy completion. Graft patency, assessed by contrast-enhanced computed tomography scan, was 90%. Mean follow-up was 25 ± 14 (range, 8-47) months (30% for >36 months). Overall 5-year survival was 66.7%, and the estimated median disease-free survival was 42 months.

CONCLUSIONS

In central NSCLCs, conservative surgery using a cryopreserved arterial allograft to replace the pulmonary artery after extended segmental resection could avoid pneumonectomy in selected patients.

[Chest wall surgery]

Despite the numerous differences among the distinct diseases of the chest wall, the surgery of this area shows certain common features. Treatment has progressively changed in the last few years due to advances in diagnostic techniques, minimally invasive procedures and reconstruction materials, and especially due to the multidisciplinary management of many diseases. Nuss' minimally invasive correction of pectus excavatum has gained devotees, although open approaches are performed with increasingly small incisions, almost comparable to the lateral incisions in Nuss' technique. Surgeons supporting the open approach also cite the evident disadvantages of the need for a steel implant for 2 or 3 years and for a second intervention to remove this implant. En-bloc resections with reconstruction using materials, which are increasingly better and covered by myocutaneous grafts in collaboration with plastic surgery departments, constitute a major advance in the treatment of chest wall tumors. Trimodal therapy for Pancoast tumors, consisting of induction chemotherapy and radiotherapy and subsequent surgical treatment of the tumor, currently provides the best results in terms of resectability and survival.

Long-term patency of the stapled bovine pericardial conduit for replacement of the superior vena cava

OBJECTIVE

Artificial prosthesis of the superior vena cava (SVC) may occlude with time. For this reason, we proposed in 2003 the use of a biological material (bovine pericardium) and devised an original technique to construct the prosthetic conduit. We hereby report the long-term results in 15 patients.

METHODS

The SVC prosthetic conduit is realized by wrapping a bovine pericardial leaflet around a 5 or 10 cm(3) syringe and stapling it on the side by a 60-80 linear stapler. This procedure is carried out intra-operatively after the size of the patient's SVC has been ascertained; the conduit is then cut to the appropriate length. We have employed this technique in 15 patients with lung (eight) or mediastinal (seven) tumors; after a minimum follow-up of 1 year, all patients underwent computed tomographic-volume rendering (CT-VR) studies of the SVC.

RESULTS

Technically, the stapled pericardial conduit has several advantages: (1) it is simple and expeditious; (2) it allows an even and regular suture line, which cannot be achieved by hand suturing; (3)'one size fits all': with one single pericardial leaflet, conduits of all sizes can be realized; this is important for an operation which is performed only few times per year; (4) patency is granted by the intrinsic rigidity of the pericardium and staple line, without the need for any reinforcement; (5) different calibers at the two extremities can be obtained by simply placing the stapler obliquely; and (6) the staple line is excellent for the orientation of the conduit while suturing. In our patients, SVC clamping time ranged between 18 and 50 min (mean 29 min); one patient needed cardiopulmonary bypass. Intra-operative anticoagulation (1.500-2.500 units of heparin) was continued postoperatively subcutaneously for 7 days and then shifted to oral anticoagulation for 6 months. One patient died postoperatively of heart failure (mortality 6%). One to 5 years after surgery, CT-VR showed full patency of the pericardial conduit, no clots or thrombus formation, and absence of collateral venous circulation in all 14 patients. One- and 5-year survival was 93% and 73%, respectively (Kaplan-Meier).

CONCLUSIONS

The stapled bovine pericardial conduit is a simple, expeditious, and economic solution to SVC replacement, and offers reliable long-term patency without permanent anticoagulation.

Lung parenchymal sparing using cryopreserved allografts for pulmonary artery reconstruction

This chapter details the indications, technique, and pitfalls of double sleeve resection with pulmonary artery (PA) replacement by a cryopreserved allograft. Both bronchial and vascular anastomoses are explained and intraoperative and postoperative allograft management are described, along with the pros and cons of each possible conduit for PA replacement.

Open approaches to posterior mediastinal tumor in adults

Thoracic surgeons must be familiar with available surgical approaches for posterior mediastinal tumors in order to choose the approach that will contribute to better prognosis and patient quality of life. An open surgical approach should be decided on based on the tumor size, location, and pathology. This article discusses the indications for the open approach in adults and outlines the surgical procedure.