Christopher Cao

Systematic review and meta-analysis of transcatheter aortic valve implantation versus surgical aortic valve replacement for severe aortic stenosis

BACKGROUND Transcatheter aortic valve implantation (TAVI) has emerged as an acceptable treatment modality for patients with severe aortic stenosis who are deemed inoperable by conventional surgical aortic valve replacement (AVR). However, the role of TAVI in patients who are potential surgical candidates remains controversial. METHODS A systematic review was conducted using five electronic databases, identifying all relevant studies with comparative data on TAVI versus AVR. The primary endpoint was all-cause mortality. A number of periprocedural outcomes were also assessed according to the Valve Academic Research Consortium endpoint definitions. RESULTS Fourteen studies were quantitatively assessed and included for meta-analysis, including two randomized controlled trials and eleven observational studies. Results indicated no significant differences between TAVI and AVR in terms of all-cause and cardiovascular related mortality, stroke, myocardial infarction or acute renal failure. A subgroup analysis of randomized controlled trials identified a higher combined incidence of stroke or transient ischemic attacks in the TAVI group compared to the AVR group. TAVI was also found to be associated with a significantly higher incidence of vascular complications, permanent pacemaker requirement and moderate or severe aortic regurgitation. However, patients who underwent AVR were more likely to experience major bleeding. Both treatment modalities appeared to effectively reduce the transvalvular mean pressure gradient. CONCLUSIONS The available data on TAVI versus AVR for patients at a higher surgical risk showed that major adverse outcomes such as mortality and stroke appeared to be similar between the two treatment modalities. Evidence on the outcomes of TAVI compared with AVR in the current literature is limited by inconsistent patient selection criteria, heterogeneous definitions of clinical endpoints and relatively short follow-up periods. The indications for TAVI should therefore be limited to inoperable surgical candidates until long-term data become available.

A Systematic Review of Extrapleural Pneumonectomy for Malignant Pleural Mesothelioma

Introduction: The primary objective of the present systematic review was to evaluate the safety and efficacy of extrapleural pneumonectomy (EPP) for patients with malignant pleural mesothelioma. Methods: A systematic review of relevant studies identified through five online search databases was performed. Two reviewers independently appraised each study. Results: Thirty-four of 58 relevant studies from 26 institutions containing the most updated data were evaluated for survival and perioperative outcomes after EPP. The median overall survival varied from 9.4 to 27.5 months, and 1-, 2-, and 5-year survival rates ranged from 36 to 83%, 5 to 59%, and 0 to 24%, respectively. Overall perioperative mortality rates ranged from 0 to 11.8%, and the perioperative morbidity rates ranged from 22 to 82%. Quality of life assessments from three studies reported improvements in nearly all domains at 3 months postoperatively. Patients who underwent trimodality therapy involving EPP and adjuvant chemoradiotherapy had a median overall survival of 13 to 23.9 months. Discussions: The current evidence suggests that selected patients with malignant pleural mesothelioma may benefit from EPP, especially when combined with neoadjuvant or adjuvant chemotherapy and adjuvant radiotherapy.

Transcatheter aortic valve implantation for high-risk patients with severe aortic stenosis: A systematic review.

OBJECTIVES The present systematic review objectively assessed the safety and clinical effectiveness of transcatheter aortic valve implantation for patients at high surgical risk with severe aortic stenosis. METHODS Electronic searches were performed in 6 databases from January 2000 to March 2009. The end points included feasibility, safety, efficacy, and durability. Clinical effectiveness was synthesized through a narrative review with full tabulation of results of all included studies. RESULTS The current evidence on transcatheter aortic valve implantation for aortic stenosis is limited to short-term observational studies. The overall procedural success rates ranged from 74% to 100%. The incidence of major adverse events included 30-day mortality (0%-25%), major ventricular tachyarrhythmia (0%-4%), myocardial infarction (0%-15%), cardiac tamponade (2%-10%), stroke (0%-10%), conversion to surgery (0%-8%), moderate to major paravalvular leak (4%-35%), vascular complication (8%-17%), valve-in-valve procedure (2%-12%), and aortic dissection/perforation (0%-4%). The overall 30-day major adverse cardiovascular and cerebral events ranged from 3% to 35%. The mean aortic valve area ranged from 0.5 to 0.8 cm(2) before and 1.3 to 2.0 cm(2) after transcatheter aortic valve implantation. The mean pressure gradient ranged from 34 to 58 mm Hg before and 3 to 12 mm Hg after transcatheter aortic valve implantation. There was no significant deterioration in echocardiography measurements during the assessment period. Death rate at 6 months postprocedure ranged from 18% to 48%. No studies had adequate follow-up to reliably evaluate long-term outcomes. CONCLUSIONS The procedure has a potential for serious complications. Although short-term efficacy based on echocardiography measurements is good, there is little evidence on long-term outcomes. The use of transcatheter aortic valve implantation should be considered only within the boundaries of clinical trials.

A systematic review and meta-analysis of surgical treatments for malignant pleural mesothelioma

BACKGROUND Malignant pleural mesothelioma (MPM) is an aggressive disease of the pleural lining with a dismal prognosis. Surgical treatments of MPM with a curative intent include extrapleural pneumonectomy and extended pleurectomy/decortication (P/D). This meta-analysis aimed to compare the perioperative and long-term outcomes of EPP and extended P/D for selected surgical candidates. METHODS A systematic review of the literature was performed on six electronic databases to identify all relevant data on comparative outcomes of extended P/D and EPP in a multimodality setting. Endpoints included perioperative mortality and morbidity, as well as long-term overall survival. RESULTS Seven relevant studies with comparative data on EPP (n=632) versus extended P/D (n=513) were identified from the current literature. Comparison of these two groups demonstrated significantly lower perioperative mortality (2.9% vs. 6.8%, p=0.02) and morbidity (27.9% vs. 62.0%, p<0.0001) for patients who underwent extended P/D compared to EPP. Median overall survival ranged between 13-29 months for extended P/D and 12-22 months for EPP, with a trend favouring extended P/D. CONCLUSIONS Although it must be emphasized that patient selection and treatment strategies differ between EPP and extended P/D, a number of comparative studies have recently been conducted to compare these two surgical techniques for patients with resectable MPM. The present study indicated that selected patients who underwent extended P/D had lower perioperative morbidity and mortality with similar, if not superior, long-term survival compared to EPP, in the context of multi-modality therapy. This may represent an important paradigm shift in the surgical management of MPM.

Video-assisted thoracic surgery versus open thoracotomy for non-small cell lung cancer: a meta-analysis of propensity score-matched patients.

OBJECTIVES This meta-analysis aimed to compare the perioperative outcomes of video-assisted thoracic surgery (VATS) with open thoracotomy for propensity score-matched patients with early-stage non-small cell lung cancer (NSCLC). METHODS Four relevant studies with propensity score-matched patients were identified from six electronic databases. Endpoints included perioperative mortality and morbidity, individual postoperative complications and duration of hospitalization. RESULTS Results indicate that all-cause perioperative mortality was similar between VATS and open thoracotomy. However, patients who underwent VATS were found to have significantly fewer overall complications, and significantly lower rates of prolonged air leak, pneumonia, atrial arrhythmias and renal failure. In addition, patients who underwent VATS had a significantly shorter length of hospitalization compared with those who underwent open thoracotomy. CONCLUSIONS In view of a paucity of high-level clinical evidence in the form of large, well-designed randomized controlled trials, propensity score matching may provide the highest level of evidence to compare VATS with open thoracotomy for patients with NSCLC. The present meta-analysis demonstrated superior perioperative outcomes for patients who underwent VATS, including overall complication rates and duration of hospitalization.

Radioembolization with yttrium microspheres for neuroendocrine tumour liver metastases

90Y microsphere radioembolization is performed by injecting the microspheres through a hepatic artery catheter placed percutaneously via the femoral or brachial artery. This study assessed the efficacy of 90Y microsphere therapy for patients with unresectable neuroendocrine tumour liver metastases (NETLMs). Potential prognostic factors were analysed for their impact on overall survival.

Systematic review and meta-analysis: techniques and a guide for the academic surgeon

With the rapidly growing literature across the surgical disciplines, there is a corresponding need to critically appraise and summarize the currently available evidence so they can be applied appropriately to patient care. The interpretation of systematic reviews is particularly challenging in cases where few robust clinical trials have been performed to address a particular question. However, risk of bias can be minimized and potentially useful conclusions can be drawn if strict review methodology is adhered to, including an exhaustive literature search, quality appraisal of primary studies, appropriate statistical methodology, assessment of confidence in estimates and risk of bias. Therefore, the following article aims to: (I) summarize to the important features of a thorough and rigorous systematic review or meta-analysis for the surgical literature; (II) highlight several underused statistical approaches which may yield further interesting insights compared to conventional pair-wise data synthesis techniques; and (III) propose a guide for thorough analysis and presentation of results.

A meta-analysis of unmatched and matched patients comparing video-assisted thoracoscopic lobectomy and conventional open lobectomy

BACKGROUND Video-assisted thoracic surgery (VATS) for patients with early-stage non-small cell lung cancer (NSCLC) has been established as a safe and feasible alternative to open thoracotomy. This meta-analysis aims to assess the potential difference between unmatched and propensity score-matched cohorts who underwent VATS versus open thoracotomy in the current literature. METHODS Three relevant studies with unmatched and propensity score-matched patients were identified from six electronic databases to examine perioperative outcomes after VATS lobectomy versus open thoracotomy for patients with early-stage NSCLC. Endpoints included perioperative mortality and morbidity, individual postoperative complications and duration of hospitalization. RESULTS Results indicate that perioperative mortality was significantly lower for VATS compared to open thoracotomy in unmatched patients but no significant difference was detected amongst propensity score-matched patients. Similarly, the incidences of prolonged air leak and sepsis were significantly lower for VATS in the unmatched cohort, but not identified in the propensity score-matched cohort. In both the unmatched and matched groups, patients who underwent VATS were found to have a significantly lower overall perioperative morbidity rate, incidences of pneumonia and atrial arrhythmias, and a shorter duration of hospitalization in comparison to patients who underwent open thoracotomy. CONCLUSIONS The present meta-analysis indicates that VATS lobectomy has superior perioperative outcomes compared to open thoracotomy in both matched and unmatched cohorts. However, the extent of the superiority may have been overestimated in the unmatched patients when compared to propensity score-matched patients. Due to the limited number of studies with available data included in the present meta-analysis, these results are only of observational interest and should be interpreted with caution.

Systematic review of trimodality therapy for patients with malignant pleural mesothelioma

BACKGROUND Malignant pleural mesothelioma (MPM) is an aggressive form of cancer arising from the pleural mesothelium. Trimodality therapy (TMT) involving extrapleural pneumonectomy with neoadjuvant or adjuvant chemotherapy and adjuvant radiotherapy is a recognized treatment option with a curative intent. Despite encouraging results from institutional studies, TMT in the treatment of MPM remains controversial. The present systematic review aims to assess the safety and efficacy of TMT in the current literature. METHODS A systematic review was performed using five electronic databases from 1 January 1985 to 1 October 2012. Studies were selected independently by two reviewers according to predefined selection criteria. The primary endpoint was overall survival. Secondary endpoints included disease-free survival, disease recurrence, perioperative morbidity and length of stay. RESULTS Sixteen studies were included for quantitative assessment, including one randomized controlled trial and five prospective series. Median overall survival ranged from 12.8-46.9 months. Disease-free survival ranged from 10-16.3 months. Perioperative mortality ranged from 0-12.5%. Overall perioperative morbidity ranged from 50-82.6% and the average length of stay was 9-14 days. CONCLUSIONS Outcomes of patients who underwent TMT in the current literature appeared to be inconsistent. Four prospective series involving a standardised treatment regimen with neoadjuvant chemotherapy indicated encouraging results based on intention-to-treat analysis. However, a small study assessing the feasibility of conducting a randomized controlled trial for TMT versus conservative treatment reported poor short- and long-term outcomes for patients who underwent pneumonectomy. Overall, results of the present systematic review suggest TMT may offer acceptable perioperative outcomes and long-term survival in selected patients treated in specialized centers.

A systematic review and meta-analysis on pulmonary resections by robotic video-assisted thoracic surgery.

BACKGROUND Pulmonary resection by robotic video-assisted thoracic surgery (RVATS) has been performed for selected patients in specialized centers over the past decade. Despite encouraging results from case-series reports, there remains a lack of robust clinical evidence for this relatively novel surgical technique. The present systematic review aimed to assess the short- and long-term safety and efficacy of RVATS. METHODS Nine relevant and updated studies were identified from 12 institutions using five electronic databases. Endpoints included perioperative morbidity and mortality, conversion rate, operative time, length of hospitalization, intraoperative blood loss, duration of chest drainage, recurrence rate and long-term survival. In addition, cost analyses and quality of life assessments were also systematically evaluated. Comparative outcomes were meta-analyzed when data were available. RESULTS All institutions used the same master-slave robotic system (da Vinci, Intuitive Surgical, Sunnyvale, California) and most patients underwent lobectomies for early-stage non-small cell lung cancers. Perioperative mortality rates for patients who underwent pulmonary resection by RVATS ranged from 0-3.8%, whilst overall morbidity rates ranged from 10-39%. Two propensity-score analyses compared patients with malignant disease who underwent pulmonary resection by RVATS or thoracotomy, and a meta-analysis was performed to identify a trend towards fewer complications after RVATS. In addition, one cost analysis and one quality of life study reported improved outcomes for RVATS when compared to open thoracotomy. CONCLUSIONS Results of the present systematic review suggest that RVATS is feasible and can be performed safely for selected patients in specialized centers. Perioperative outcomes including postoperative complications were similar to historical accounts of conventional VATS. A steep learning curve for RVATS was identified in a number of institutional reports, which was most evident in the first 20 cases. Future studies should aim to present data with longer follow-up, clearly defined surgical outcomes, and through an intention-to-treat analysis.