Chronic Thromboembolic Pulmonary Hypertension. The Journey from a Curiosity to a Cure.

Chronic thromboembolic pulmonary hypertension is a progressive and life-threatening condition that is believed to be related to inadequate dissolution of acute pulmonary thromboemboli, followed by fibrotic organization. Without appropriate treatment, progressive pulmonary hypertension, right ventricular failure, and death may occur. While the disorder was initially described nearly a century ago in autopsy studies, antemortem diagnosis became feasible with the advent of cardiac catheterization and angiography techniques in the 1940s, while surgical thromboendarterectomy was not attempted until the 1960s. However, this procedure initially had high mortality rates until refinements in management and surgical techniques resulted in much improved outcomes starting in the 1980s. Many questions remain about the pathophysiology and epidemiology of this condition, with unclear contributions of genetics and environmental exposures. The optimal approach to diagnosis also continues to evolve, with improvements in preoperative imaging and hemodynamic assessment. Treatment of chronic thromboembolic pulmonary hypertension has not remained static, as surgical techniques continue to improve and newer pharmacological treatments and percutaneous catheter-based interventions may play therapeutic roles in selected patients. This is the introductory article of a series that provides a state-of-the-art review of chronic thromboembolic pulmonary hypertension.

Hybrid procedures for acute limb ischemia.

The most efficient treatment for acute arterial embolism is operative embolectomy using Fogarty's balloon catheter, especially if a single large artery is involved. Unfortunately, although the early surgical success of arterial thromboembolectomy often seems acceptable, the early clinical outcome still remains unsatisfactory. This may be related to the incomplete restoration of perfusion (i.e., residual thrombus in distal vessels not reached by the balloon catheter thromboembolectomy), propagation of residual thrombi or presence of underlying steno-occlusive lesions. In such a situation a meticulous intraoperative assessment of the adequacy of clot removal is decisive. Residual thrombus, chronic atherosclerotic disease and even vessel injuries secondary to balloon catheter passage can be corrected by endovascular techniques (hybrid procedures). The combination of surgical and endovascular options may overcome the limitations that characterize the traditional approach, and it is likely that in the future many treatments will be a mix of techniques that can be performed by vascular surgeons in the operating room or in a dedicated endovascular suite. This review article summarizes the hybrid treatment options for acute arterial occlusion caused by either embolism or local thrombosis.

Historical perspective: surgery for chronic thromboembolic disease.

This article provides a historical perspective for our current understanding of chronic thromboembolic pulmonary hypertension and surgery for this disease. It chronicles the developments in surgical techniques that have made pulmonary endarterectomy the procedure of choice for obstruction of pulmonary vessels by organized thromboemboli and secondary vessel wall thickening.

Historical perspective: surgery for chronic thromboembolic disease.

Obstruction of major pulmonary vessels with organized thromboemboli is a rare sequelae of acute pulmonary embolic disease. Depending on the extent and duration of vascular occlusion, patients experiencing this unusual disorder may develop significant pulmonary hypertension and cor pulmonale. If left untreated, the ultimate clinical outcome is right heart failure and death. Over the past several decades, the description of this clinical entity has evolved from an autopsy curiosity to a recognized cause of chronic pulmonary hypertension. Also, during this same time period, surgical capabilities have greatly advanced, providing these patients a potentially life-saving remedy for this debilitating form of pulmonary vascular disease. This article provides a historical perspective for our current understanding of major vessel chronic thromboembolic pulmonary hypertension as a distinct clinical disorder. It also chronicles the developments in surgical techniques that have made thromboendarterectomy of the pulmonary arterial bed a reality.

[Coronary endarterectomy]. / Endarterectomía coronaria.

The technique of coronary endarterectomy, in coronary artery surgery, has been controversial and alternatively indicated or contraindicated by different authors. In this paper coronary endarterectomy is reviewed, including its definition, history and development of different techniques. Early and late results of the main papers in the literature are commented on as well as our results. The surgical technique of endarterectomy in the different coronary artery territories is described with the primary indications and contraindications. Coronary endarterectomy is a valid and well established technique that can provide possibilities of revascularization in patients with extended and diffused coronary artery obstructions, which are unable to be treated with conventional coronary artery bypass grafts. Operative mortality and morbidity are slightly higher, but long-term results, as far as survival and functional class are concerned, are similar to standard coronary artery surgical procedures.

Surgical recanalization of occluded peripheral arteries.

This article, reflecting on the surgical recanalization of occluded peripheral arteries, has exposed the very essence of vascular surgery. Only the pioneering cardiac anomalies repaired by Gross (patent duct arteriosus, 1938), Blalock and Taussig (tetralogy of Fallot, 1944), and Crafoord and Nylin (coarctation, 1945) and the legendary aortic grafting operations of Oudot (occlusion, 1950) and Dubost and coworkers (aneurysm, 1951) are not a part of this article. The contributions to surgical recanalization of the occluded peripheral arteries are numerous. Some are well conceived, and others are innovative. Perhaps the most significant technique of all, endarterectomy itself, began purely as a serendipitous event. The startling impact of dos Santos' revolutionaly "disobliteration" was realized at once. Intimal injury during the operation did not cause inevitable thrombosis, as historically taught. Thus, all vascular interventions, either endarterectomy, graft repair, or the newer endovascular techniques discussed in this issue, would not have been developed without the understanding of the tolerance of the human intima to injury. Thromboendarterectomy, the basis of surgical recanalization of occluded arteries, unlocked the mystery of arterial rethrombosis after intervention. Recognizing these crucial facts, it will have a lasting place in the expanded discipline of vascular disease and its treatment. Dos Santos, the European founder of endarterectomy, and Wylie, the American pioneer and proponent of endarterectomy, were great friends in life (Fig. 4) and would certainly be pleased to see the further development of technology aimed at the treatment of atherosclerotic obstruction of the peripheral arteries.