Ramin Malekan

Peripheral Extracorporeal Membrane Oxygenation: Comprehensive Therapy for High-Risk Massive Pulmonary Embolism

BACKGROUND Although commonly reserved as a last line of defense, experienced centers have reported excellent results with pulmonary embolectomy for massive and submassive pulmonary embolism (PE). We present a contemporary surgical series for PE that demonstrates the utility of peripheral extracorporeal membrane oxygenation (pECMO) for high-risk surgical candidates. METHODS Between June 2005 and April 2011, 29 patients were treated for massive or submassive pulmonary embolism, with surgical embolectomy performed in 26. Four high-risk patients were placed on pECMO, established by percutaneously cannulating the right atrium through a femoral vein and perfusing by a Dacron graft anastomosed to the axillary artery. A small, extracorporeal, rotary assist device was used, interposing a compact oxygenator in the circuit, and maintaining anticoagulation with heparin. RESULTS Extracorporeal membrane oxygenation was weaned in 3 of 4 patients after 5.3 days (5, 5, and 6), with normalization of right ventricular dysfunction and pulmonary artery pressure (44.0 ± 2.0 to 24.5 ± 5.5 mm Hg) by ECHO. Follow-up computed tomographies showed several peripheral, nearly resorbed emboli in 1 case and complete resolution in 2 others. The fourth patient, not improving after 10 days, underwent surgery where an embolic liposarcoma was extracted. For all 29 cases, hospital and 30-day mortality was 0% and all patients were discharged, with average postoperative length of stay of 15 days for embolectomy and 17 days for pECMO. CONCLUSIONS Heparin therapy with pECMO support is a rapid, effective option for patients who might benefit from pulmonary embolectomy but are at high risk for surgery.

Acute aortic syndrome.

The term acute aortic syndrome refers to a heterogeneous group of conditions that cause a common set of signs and symptoms, the foremost of which is aortic pain. Various pathologic entities may give rise to this syndrome, but the topic has come to focus on penetrating aortic ulcer and intramural hematoma and their relation to aortic dissection. Penetrating aortic ulcer is a focal atherosclerotic plaque that corrodes a variable depth through the intima into the media. Intramural hematoma is a blood collection within the aortic wall not freely communicating with the aortic lumen, with restricted flow. It may represent a subcategory of aortic dissection that manifests different behavior by virtue of limited flow in the false lumen. This article reviews the current literature regarding acute aortic syndrome, focusing on management options.

Selective cerebral perfusion: A review of the evidence

OBJECTIVE With the realization that hypothermia was neuroprotective, hypothermic selective antegrade cerebral perfusion was adopted by many surgical groups for aortic arch resection, prompting experimental and clinical studies to elaborate technical refinements and safe parameters of selective antegrade cerebral perfusion. We review the evidence for optimum management of perfusion pressure, flow, temperature, pH, hematocrit, and cannulation access. METHODS Underperfusion and overperfusion impair neurologic function after selective antegrade cerebral perfusion. Overperfusion--including excessive flow and pressure--is expressed experimentally as an increase in intracranial pressure, indicative of cerebral edema, and causes slow neurobehavioral recovery. As the safe limits of moderate and mild hypothermic selective antegrade cerebral perfusion are being explored in many aortic centers, the ischemic tolerance of the spinal cord during lower-body circulatory arrest becomes a new focus of concern. RESULTS Although a significant portion of the population has an incomplete circle of Willis, contralateral flow via extracranial collaterals has permitted the successful use of various cannulation techniques. Unilateral perfusion is adequate for short-term (<40 minutes) selective antegrade cerebral perfusion, even at higher temperatures (24 °C-28 °C). However, if prolonged periods of selective antegrade cerebral perfusion are anticipated, evidence suggests that better cerebral protection is obtained with bilateral selective antegrade cerebral perfusion. CONCLUSIONS On the basis of these experimental and clinical studies, certain recommendations for the use of nonpulsatile selective antegrade cerebral perfusion can be made.

Aortic surgery in pregnancy

&NA; Pregnancy engenders changes in hemodynamics and the aortic wall that make a woman more susceptible to aortic dilatation and dissection. This is particularly true of women with aortic dilatation and an aortopathy, including the inherited fibrillinopathies, bicuspid aortic valve, and Turner syndrome. Women in these risk groups may be served best by undergoing elective aortic surgery before becoming pregnant. However, some women present during pregnancy with significant aortic dilatation, rapid expansion, or aortic dissection, and strategies to deal with these situations, while optimizing maternal and fetal outcomes, change as gestation progresses. This review summarizes the approaches to the management of aortic diseases and the conduct of aortic surgery in pregnancy.

Malperfusion in Type A Dissection: Consider Reperfusion First

Acute type A aortic dissection (ATAAD) is a vascular catastrophe, with a mortality of 1% per hour for the first 48 hours without surgical intervention. Of the diverse causes of morbidity and mortality associated with ATAAD, malperfusion, which complicates 20%-50% of cases, is particularly lethal. Although malperfusion can affect any vascular bed, this review focuses on the 3 most devastating: coronary, cerebral, and visceral malperfusion syndromes (MPS). Essentially, there are 3 methods of restoring flow to malperfused areas: central repair, fenestration, and direct revascularization of affected arteries. Of these, emergency central aortic repair is the accepted primary strategy, as it most expeditiously eliminates the risk of rupture, and accordingly, our protocol is to transfer ATAAD cases directly to the operating room. However, central repair is not necessarily the most expedient strategy for resolving malperfusion, and in some cases, malperfusion persists despite central repair. At some point, with certain cases of severe malperfusion, the mortality from end organ damage exceeds the mortality risk of rupture and recent reports suggest that these cases may be best managed by emergency reperfusion of the affected vascular bed, followed by central repair.

Esophago-pericardial Fistula and Pneumopericardium from Caustic ingestion and Esophageal Stent

Esophagopericardial fistulas are rare. Most reported cases are related to malignancy or prior surgical intervention. We report a case of an esophagopericardial fistula presenting as pneumopericardium and purulent pericarditis in a patient with a history of caustic ingestion and an esophageal stent.