CV Directions Vol. 2, No. 2 | Page 9

CV  Matthew C. Bozeman Charles B. Ross Division of Vascular Surgery and Endovascular Therapeutics, Department of Surgery, University of Louisville intra-abdominal hypertension and abdominal compartment syndrome in association with ruptured abdominal aortic aneurysm in the endovascular era: vigilance remains critical Abstract Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are common complications of ruptured abdominal aortoiliac aneurysms (rAAAs) and other abdominal vascular catastrophes even in the age of endovascular therapy. Morbidity and mortality due to systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF) are significant. Recognition and management of IAH are key critical care measures which may decrease morbidity and improve survival in these vascular patients. Two strategies have been utilized: expectant management with prompt decompressive laparotomy upon diagnosis of threshold levels of IAH versus prophylactic, delayed abdominal closure based upon clinical parameters at the time of initial repair. Competent management of the abdominal wound with preservation of abdominal domain is also an important component of the care of these patients. 1. Introduction Patients who survive an initial operation for an intra-abdominal catastrophic event, such as a ruptured abdominal aortic aneurysm (rAAA) or other abdominal vascular catastrophes such as complicated mesenteric revascularization, often suffer from severe physiologic derangements. In this review, we describe published experience with IAH and ACS complicating abdominal vascular catastrophes, experience with ACS complicating endovascular repair of rAAAs, and techniques for management of the abdominal wound. Vigilance and appropriate management of IAH and ACS remains critically important in decreasing morbidity and optimizing survival following catastrophic intra-abdominal vascular events. Kron et al. [7] in 1984 described ACS and end-organ failure emphasizing oliguria managed successfully with decompressive laparotomy following an initial operation for repair of rAAA. Fietsam et al. [8] first described delayed abdominal closure and subsequent management in 1989. Since that time, further experiences and lessons learned from diagnosing and treating ACS have been reported [1, 4, 9–20]. Factors contributing to their critical illness include hemodynamic instability, massive fluid resuscitation, transfusion of blood products, hypothermia, acidosis, and lengthy operations with resultant fluid shifts. ACS is recognized as a major cause of death after treatment for rAAA with short-term mortality rates as much as 5 times greater than observed in patients without ACS even in patients treated by endovascular techniques [1]. 2. The Physiologic Basis of Abdominal Compartment Syndrome Although endovascular repair of rAAA (REVAR) has shown promise in reducing these challenges and improving survival in patients with suitable anatomy [2], a reported 10–20% of patients treated by endovascular techniques still develop ACS [1–6]. Recognition and management of IAH and ACS complicating open or endovascular repairs is critically important in decreasing morbidity and improving survival from rAAA. IAH is defined as an intra-abdominal pressure (IAP) greater than 12 mmHg in consecutive, standardized measurements with the risk of progression to overt ACS, defined as IAP greater than 20 mmHg or abdominal perfusion pressure less than 60 mmHg with end-organ dysfunction [21], increasing as IAP increases. CV DIRECTIONS VOL. 2, NO. 2 The end result of intra-abdominal hypertension is impaired organ perfusion resulting in MOF. A relationship exists as a continuum between IAH and ACS. IAH is evaluated with a grading system reported in 2006 by the World Conference on Abdominal Compartment Syndrome (Table 1) [21]. Early in the disease process, prior to stage III, patients develop oliguria, elevat ed end-inspiratory pressures, and 9