P. Michael McFadden

The evolution of intraoperative support in lung transplantation: Cardiopulmonary bypass to extracorporeal membrane oxygenation

The report of the first successful clinical heart-lung transplant by Reitz and colleagues at Stanford, and those that followed, ushered in a new enthusiasm for lung transplantation. It was soon recognized that lung transplantation was possible without concomitant heart transplantation, and en bloc double lung transplantation using cardiopulmonary bypass soon evolved. Machuca and colleagues of the University of Toronto compare outcomes of intraoperative extracorporeal membrane oxygenation (ECMO) versus cardiopulmonary bypass (CPB) support in patients undergoing lung transplantation (LTx). This study is the first to address which method of extracorporeal intraoperative support may be superior in LTx, a topic of intense current interest. The matched cohorts (33 ECMO vs 66 CPB) resulted from a 7-year (2007-2013) review of 673 LTxs performed at their Toronto program. Although retrospective and nonrandomized, the study groups are well matched and adequately powered; inclusion and exclusion criteria are sufficiently defined. The contemporary period of LTx began in the late 1980s, following a critical assessment of experimental and clinical results of en bloc double LTx, commonly performed at that time. These investigators determined that en bloc ‘‘double’’ LTx, utilizing a central tracheal anastomosis, was technically feasible but frequently attended with severe airway complications, including dehiscence, necrosis, mediastinitis, sepsis, stenosis, and poor longterm survival. To address this problem, a technical alteration in the airway anastomotic technique was introduced. The en bloc tracheal anastomosis was abandoned for a more easily mastered bilateral sequential bronchial anastomosis. This approach avoided the need for CPB in many patients, reduced postoperative hemorrhage, and practically eliminated the life-threatening complications of airway necrosis and dehiscence. Bilateral sequential LTx, with or

Aggressive Approach to Pulmonary Embolectomy for Massive Acute Pulmonary Embolism: A Historical and Contemporary Perspective

In this issue of Mayo Clinic Proceedings, Sareyyupoglu et al1 of Mayo Clinic describe a series of 18 patients who had aggressive surgical treatment for acute pulmonary embolism (PE). The authors were careful to define the presence of cardiogenic shock and severe right ventricular dysfunction as indications for urgent surgical embolectomy in these critically ill patients. The surgical technique used for acute pulmonary embolectomy is a variation of the modified Trendelenburg procedure used by many surgeons.2-4 Specifically, the operation was conducted through a median sternotomy with aortic and bicaval cannulation and normothermic cardiopulmonary bypass. Incisions into the main pulmonary artery to remove the clot were extended into the distal pulmonary arteries when necessary. The lungs were massaged through bilateral pleurotomies to facilitate clot removal. Inferior vena cava (IVC) filters were placed either preoperatively or within the first 24 hours after surgery to prevent reembolization. Perioperative management included the widely accepted measures of heparin anticoagulation and vena cava filters to prevent progression of deep venous thrombosis and recurrent PE.5-7 Sareyyupoglu et al1 reported a respectable 78% early and 67% long-term survival rate in these severely compromised patients. This aggressive approach to an otherwise lethal problem suggests that acceptable survival is possible in a selected group of patients. Their approach may herald a resurgence of interest in surgical pulmonary embolectomy to treat severe hemodynamic compromise.

Rapidly fatal disseminated acanthamoebiasis in a single lung transplant recipient

BACKGROUND Lung transplant recipients are at great risk for developing various infectious complications. These infections portend a significant morbidity and mortality throughout their lifetime following transplantation. At times, cutaneous manifestations are the only clues to systemic infection. CASE REPORT A 62 year-old man with a history of idiopathic pulmonary fibrosis presented 6 months after receiving bilateral sequential cadaveric lung transplantation for anorexia, early satiety, weight loss, exertional dsypnea, arthralgia, and depression. On exam, two rapidly growing non-painful 1.5-3 centimeter erythematous nodules with purulent draining on the anterior chest wall were noted. On Hospital Day 7, the patent was found to be un-responsive, hypotensive, and febrile. Brain imaging revealed diffuse thick nodular enhancement of leptomeningeal surface and multiple areas of hypodenisty associated with mass effect in the bilateral vermis and cerebellar hemispheres with effacement of the fourth ventricle. CSF PCR analysis showed Acanthamoeba sp. confirmed by the Center for Disease Control. Despite multi-modal therapy, his clinical course deteriorated and resulted in brain death. CONCLUSION Acanthamoeba infection is extremely rare in thoracic organ recipients. We report the fifth case of progressive disseminated acanthamoebiasis in a lung transplant recipient.

A Multicenter RCT of Zephyr® Endobronchial Valve Treatment in Heterogeneous Emphysema (LIBERATE)

Rationale: This is the first multicenter randomized controlled trial to evaluate the effectiveness and safety of Zephyr Endobronchial Valve (EBV) in patients with little to no collateral ventilation out to 12 months. Objectives: To evaluate the effectiveness and safety of Zephyr EBV in heterogeneous emphysema with little to no collateral ventilation in the treated lobe. Methods: Subjects were enrolled with a 2:1 randomization (EBV/standard of care [SoC]) at 24 sites. Primary outcome at 12 months was the &Dgr;EBV‐SoC of subjects with a post‐bronchodilator FEV1 improvement from baseline of greater than or equal to 15%. Secondary endpoints included absolute changes in post‐bronchodilator FEV1, 6‐minute‐walk distance, and St. Georges Respiratory Questionnaire scores. Measurements and Main Results: A total of 190 subjects (128 EBV and 62 SoC) were randomized. At 12 months, 47.7% EBV and 16.8% SoC subjects had a &Dgr;FEV1 greater than or equal to 15% (P < 0.001). &Dgr;EBV‐SoC at 12 months was statistically and clinically significant: for FEV1, 0.106 L (P < 0.001); 6‐minute‐walk distance, +39.31 m (P = 0.002); and St. Georges Respiratory Questionnaire, −7.05 points (P = 0.004). Significant &Dgr;EBV‐SoC were also observed in hyperinflation (residual volume, −522 ml; P < 0.001), modified Medical Research Council Dyspnea Scale (−0.8 points; P < 0.001), and the BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) index (−1.2 points). Pneumothorax was the most common serious adverse event in the treatment period (procedure to 45 d), in 34/128 (26.6%) of EBV subjects. Four deaths occurred in the EBV group during this phase, and one each in the EBV and SoC groups between 46 days and 12 months. Conclusions: Zephyr EBV provides clinically meaningful benefits in lung function, exercise tolerance, dyspnea, and quality of life out to at least 12 months, with an acceptable safety profile in patients with little or no collateral ventilation in the target lobe. Clinical trial registered with www.clinicaltrials.gov (NCT 01796392).

The surgeon's perspective on oesophageal disease, and what it means to pathologists

GERD and its potential complications of Barrett’s oesophagus and oesophageal adenocarcinoma are now the most important disease processes for oesophageal surgeons. A major impact on this disease will likely come from the development of cost-effective screening and diagnostic modalities which identify patients who are at risk for developing oesophageal cancer. The surgical approach to Barrett’s oesophagus and oesophageal adenocarcinoma will continue to evolve in response to advances in ablative therapy and ER. The role of the pathologist, with expertise in the diagnosis of Barrett’s oesophagus, will become more prominent as we better define the histological predictors of oesophageal adenocarcinoma. A collaborative effort between pathologists and surgeons is essential in determining the timing and best approach for interventional therapy.

Contemporary Surgical Management of Acute Massive Pulmonary Embolism

Pulmonary embolism (PE) is the most lethal pulmonary condition in the United States and internationally. It is also the third most common cause of death in hospitalized pa‐ tients. Since the introduction of computed tomographic pulmonary angiography (CT-PA), the estimated incidence of PE has risen from 62.1 to 112.3 cases per 100,000 [1]. Untreated, the associated mortality of PE is as high as 30% with recurrent embolism being the most common cause. Globally, systemic anticoagulation is the mainstay of treatment for both chronic and acute PE. In the case of acute massive PE (presenting with hypotension and systolic arterial pressure less than 90 mm Hg) the prognosis is much graver and associat‐ ed with a mortality of 30-60%, second only to sudden cardiac death as a cause of sudden death. This condition mandates a more aggressive and urgent algorithm for diagnosis and treatment. Prompt and appropriate treatment, which may include surgical pulmonary em‐ bolectomy, can be life-saving.

Optimal Approach for Repair of Left Atrial-Esophageal Fistula Complicating Radiofrequency Ablation

Left atrial-esophageal fistula after endovascular radiofrequency ablation for cardiac arrhythmias is a life-threatening complication. Immediate surgical repair offers the best chance for survival. The optimal surgical technique is unknown. We describe our recommended surgical approach.

Concurrent Aortic Valvular Disease and Pulmonary Sequestration: Clinical Implications

Pulmonary sequestration refers to segmental lung tissue that has no connection with the bronchial tree or pulmonary arteries. In adults, the clinical sequelae are usually related to infection. Patients are typically referred for sequestrectomy even when they are asymptomatic. There are no guidelines for treating patients who have pulmonary sequestration and coexisting cardiac valvular disease, in which case the venous drainage patterns of sequestra pose the additional risks of infective endocarditis and volume overload. We present the cases of 2 adult patients--one symptomatic and one asymptomatic--who had concurrent aortic valvular disease and pulmonary sequestration, and we discuss the factors involved in our evaluation of their cardiac risk and our treatment decisions. In view of the sparse data to predict cardiac risks, we think that pulmonary sequestrectomy in adult patients with concurrent valvular conditions should be considered on a case-by-case basis.

Iatrogenic Tracheal Injury

A49-year-old woman underwent ventral hernia repair. Postoperatively she experienced neck swelling and a voice change. Palpable cervical crepitance prompted a computed tomography of the chest, which revealed mediastinal emphysema and an extensive defect involving the entire length of the intrathoracic membranous trachea. The esophagus seemed intact (Fig 1). With worsening subcutaneous emphysema and impending respiratory failure, the patient was taken to the operating room for intubation and evaluation of the injury. In the operating room, she was intubated to just below the vocal cords. Fiberoptic bronchoscopy revealed a long posterior wall laceration that extended from the neck to the carina (Fig 2). To avoid the risk of an unstable airway, the endotracheal tube was passed into the left mainstem bronchus. A double lumen endotracheal tube was exchanged over an exchange catheter under bronchoscopic guidance. Through a right thoracotomy the azygous was divided