Surgical management of stage III thymic tumors

Surgical management of thymic epithelial tumors

Resection is the mainstay of treatment for thymic epithelial tumors (TETs), with complete removal of the tumor and involved organs being the ultimate aim. The choice of surgical approach plays a major role in defining treatment success, and the optimal choice of method should thus provide an adequate surgical view to achieve complete tumor resection. While median sternotomy is considered the gold standard for access to the mediastinum, several minimally invasive approaches to thymectomy have been described, including video-assisted robotic-assisted thymectomy, although the oncological outcomes of that procedure remain unclear. A multimodal approach incorporating chemotherapy or chemoradiotherapy followed by extended surgery may improve resectability and outcomes for patients with advanced TETs. Surgical debulking is also reportedly acceptable for invasive thymoma because of its potential for achieving favorable outcomes. Re-resection is an acceptable option for patients with recurrent thymoma after initial resection, and repeat resection for recurrent pleural dissemination seems effective. Here, the literature on current clinical practices in the surgical management and treatment of TETs is reviewed.

Robotic thoracic surgery for resection of thymoma and tumors of the thymus: technical development and initial experience

Objective:

To evaluate the results of resection of tumors of the thymus by robotic thoracic surgery, analyzing the extent of resection, postoperative complications, time of surgery, and length of stay.

Methods:

Retrospective study from a database involving patients diagnosed with a tumor of the thymus and undergoing robotic thoracic surgery at one of seven hospitals in Brazil between October of 2015 and June of 2018.

Results:

During the study period, there were 18 cases of resection of tumors of the thymus: thymoma, in 12; carcinoma, in 2; and carcinoid tumor, in 1; high-grade sarcoma, in 1; teratoma, in 1; and thymolipoma, in 1. The mean lesion size was 60.1 ± 32.0 mm. Tumors of the thymus were resected with tumor-free margins in 17 cases. The median (interquartile range) for pleural drain time and hospital stay, in days, was 1 (1-3) and 2 (2-4), respectively. There was no need for surgical conversion, and there were no major complications.

Conclusions:

Robotic thoracic surgery for resection of tumors of the thymus has been shown to be feasible and safe, with a low risk of complications and with postoperative outcomes comparable to those of other techniques.

Is a diagnostic video-assisted thoracoscopic thymectomy an acceptable first-line approach to the suspicious anterior mediastinal mass?

INTRODUCTION

The incidental early-stage thymic mass presents a diagnostic challenge. Video-assisted thoracoscopic (VAT) thymectomy is an attractive but potentially morbid solution. The aim was to show it can be safely applied as a first-line modality in those with undiagnosed thymic enlargement with acceptable long-term results.

METHODS

A total of 45 patients were identified (24 male, median age 52 interquartile range [IQR]: 41-66 years) in a 14-year experience who had CT evidence of an enlarged, possibly malignant thymic mass, but no tissue diagnosis before undertaking VAT thymectomy. The clinical outcomes of both benign and malignant diagnoses were compared.

RESULTS

Myasthenic symptoms were present in 20 patients (44%), whereas 15 (33%) were asymptomatic. Benign lesions were resected in 27 patients (60%): thymic hyperplasia (56%), thymic cyst (33%), lipoma (7%) and xanthogranulomatous inflammation (4%). Of the 18 malignant patients, 82% had thymoma (three had Masaoka Stage I, 11 Stage II and one Stage III), 6% thymic carcinoma, 6% teratoma and 6% seminoma. Seven patients required radiotherapy for R1 resection. There was no difference in median hospital stay in either group: Benign group: 4 versus 5 days (P = 0.07). One patient in both groups required conversion to open. Two patients in the malignant group had significant morbidity (one myocardial infarction and one pulmonary embolism). There were no cases of tumour recurrence or mortality at a median follow-up of 6.6 years (IQR: 4.4-9.5 years).

CONCLUSION

Right-sided diagnostic VAT thymectomy is a safe and effective first-line approach to suspected malignant thymic enlargement. At 5-year follow-up, there were no cases of recurrence in the malignant group.

Tumours of the thymus: a cohort study of prognostic factors from the European Society of Thoracic Surgeons database

OBJECTIVES

A retrospective database was developed by the European Society of Thoracic Surgeons, collecting patients submitted to surgery for thymic tumours to analyse clinico-pathological prognostic predictors.

METHODS

A total of 2151 incident cases from 35 institutions were collected from 1990 to 2010. Clinical-pathological characteristics were analysed, including age, gender, associated myasthenia gravis stage (Masaoka), World Health Organization histology, type of thymic tumour [thymoma, thymic carcinoma (TC), neuroendocrine thymic tumour (NETT)], type of resection (complete/incomplete), tumour size, adjuvant therapy and recurrence. Primary outcome was overall survival (OS); secondary outcomes were the proportion of incomplete resections, disease-free survival and the cumulative incidence of recurrence (CIR).

RESULTS

A total of 2030 patients were analysed for OS (1798 thymomas, 191 TCs and 41 NETTs). Ten-year OS was 0.73 (95% confidence interval 0.69-0.75). Complete resection (R0) was achieved in 88% of the patients. Ten-year CIR was 0.12 (0.10-0.15). Predictors of shorter OS were increased age (P < 0-001), stage [III vs I HR 2.66, 1.80-3.92; IV vs I hazard ratio (HR) 4.41, 2.67-7.26], TC (HR 2.39, 1.68-3.40) and NETT (HR 2.59, 1.35-4.99) vs thymomas and incomplete resection (HR 1.74, 1.18-2.57). Risk of recurrence increased with tumour size (P = 0.003), stage (III vs I HR 5.67, 2.80-11.45; IV vs I HR 13.08, 5.70-30.03) and NETT (HR 7.18, 3.48-14.82). Analysis using a propensity score indicates that the administration of adjuvant therapy was beneficial in increasing OS (HR 0.69, 0.49-0.97) in R0 resections.

CONCLUSIONS

Masaoka stages III-IV, incomplete resection and non-thymoma histology showed a significant impact in increasing recurrence and in worsening survival. The administration of adjuvant therapy after complete resection is associated with improved 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.