Aprotinin in deep hypothermic circulatory arrest

Bleeding Following Deep Hypothermia and Circulatory Arrest in Children

Deep hypothermic circulatory arrest (DHCA) is a technique of extracorporeal circulation commonly used in children with complex congenital heart defects undergoing surgical repairs. The use of profound cooling (20°C) and complete cessation of circulation allow adequate exposure and correction of these complex lesions, with enhanced cerebral protection. However, the profound physiologic state of DHCA results in significant derangement of the coagulation system and a high incidence of postoperative bleeding. This review examines the impact of DHCA on bleeding and transfusion requirements in children and the pathophysiology of DHCA-induced platelet dysfunction. It also focuses on possible pharmacologic interventions to decrease bleeding following DHCA in children.

Aprotinin and renal dysfunction

Aprotinin is a polypeptide serine protease inhibitor used to prevent bleeding and need for transfusions in patients having heart surgery. A recent analysis of an observational study data set suggested the use of aprotinin was associated with an increased risk of developing renal failure. The present article reviews the data from basic science studies in tissues, animals and man together with the data from observational studies and randomised controlled trials. The interpretation of the data is hampered owing to the use of different endpoints to describe mild/moderate renal impairment. Nonetheless, the evidence points to aprotinin use being associated with a transient small rise in plasma creatinine concentration in certain patients. There is no evidence for an increased risk of developing new renal failure requiring dialysis/renal replacement therapy.

Safety aspects of aprotinin therapy in cardiac surgery patients

Aprotinin is the only agent with Class A Level 1 evidence for reduction in rates of transfusion and return to operating theatre to control bleeding after heart surgery. Principal on the list of safety issues raised over the years are increased risk for: a) thrombosis; and b) renal dysfunction. With multiple administrations, hypersensitivity reactions have emerged as a further safety concern. This review discusses these issues, based on the examination of > 500 published articles. The article also specifically places in context the data presented recently from the observational McSPI database analysis. This report suggested that aprotinin should be withdrawn from human use as serious safety issues have been ignored or missed, an inference not in agreement with the majority of the human safety literature.

Aprotinin use in thoracic aortic surgery: Safety and outcomes

OBJECTIVES

Previous studies of aprotinin use in thoracic aortic surgery, limited in size and design, reported minimal information regarding outcomes other than blood loss and transfusion. The evaluation of impact of aprotinin on surgical outcomes in a large sample is needed.

METHODS

Patients at Yale New Haven Hospital undergoing thoracic aortic surgery (aneurysm repair, dissections, penetrating ulcers, intramural hematomas) between 1995 and 2003 were considered for inclusion. Each patient receiving aprotinin was matched to a control per preoperative profile (age, gender, urgency of surgery, dissection/location of aortic disease). Data (surgical specifics, demographic variables, comorbidities, disease location-related variables, preoperative medications, intraoperative medications, surgical/operative data) were abstracted from the records of successfully matched aprotinin-treated patients and controls (n = 168). Comparison and determination of success of matching were performed using bivariate analyses. Outcome variables were compared using statistical tests for paired data. Supplementary unpaired and regression analyses were also performed.

RESULTS

Baseline demographics of groups were similar, although controls had reduced history of aortic disease, but greater intraoperative use of lysine analogs (P < .05). Aprotinin significantly reduced platelet transfusion (P < .05). Paired bivariate analyses showed a tendency toward reduced ventilation time, pulmonary complications, and permanent arrhythmias (P < .05) associated with aprotinin. Supplementary analyses were supportive only for pulmonary complications and permanent arrhythmias.

CONCLUSIONS

The current evaluation substantiates previous reports that aprotinin may be safe to use and likely to improve some outcomes of thoracic aortic surgery. However, further studies for rare safety and efficacy end points are warranted.

Coma Might Not Preclude Emergency Operation in Acute Aortic Dissection

BACKGROUND

Syncope or new onset focal neurologic deficits are described in as many as one fifth of patients with acute aortic dissection referred for surgery. Coma or stroke caused by involvement of the arch vessels and secondary brain malperfusion is considered a major contraindication for emergency aortic repair. Initial experience with emergency operation in selected patients with acute type A aortic dissection complicated by coma is described.

METHODS

Five comatose (median Glasgow coma score, 5.5), hemodynamically stable (systolic blood pressure > or = 100 mm Hg) patients with preserved pupillary reactivity and coma duration of less than 12 hours underwent emergency surgical repair. The ascending aorta was always replaced using profound hypothermic circulatory arrest.

RESULTS

There were no operative deaths. No hemorrhagic brain infarction developed postoperatively. Ischemic strokes were documented by radiology in 3 patients, and were always right-sided. Four patients returned to normal life with no neurologic sequelae, whereas 1 patient showed partially recovered left hemiparesis and mild cognitive impairment.

CONCLUSIONS

Coma may not represent an absolute contraindication for resuscitative surgery in hemodynamically stable patients with acute type A aortic dissection. A larger experience is necessary to draw more definitive conclusions.

Circulatory arrest for repair of postcoarctation site aneurysm

BACKGROUND

Aneurysm at previous coarctation repair may be seen more frequently as children operated for this condition survive into adulthood. We use deep hypothermic circulatory arrest to repair these aneurysms.

METHODS

A case series was conducted using 12-year, single-institution, retrospective chart review.

RESULTS

Twenty-one patients underwent left thoracotomy and repair of aneurysm at the site of previous coarctation repair. Three cases presented emergently as aortobronchial fistulas. The age range was 16 to 73 years (median, 26 years). The median circulatory arrest time was 33 minutes (range, 22 to 55 minutes). Repair involved interposition graft replacement. Six patients required additional tube graft replacement of the left subclavian artery. There was 1 operative mortality in a patient having a hypoxic brain injury secondary to an anaphylactic reaction to a plasma expander. There were no embolic strokes or paraplegia. One patient had a recurrent laryngeal nerve paresis. There was 1 case of Horner's syndrome after subclavian artery replacement.

CONCLUSIONS

Circulatory arrest allows for the accurate repair of this difficult pathologic process and avoids the risk of clamp-related injuries. Follow-up out to 16 years demonstrates this technique of repair to be durable, with no late deaths or reoperations for recurrent aneurysm.

First-stage palliation for hypoplastic left heart syndrome in the twenty-first century

Improved understanding of the postoperative physiology and experience with the surgical techniques and perioperative care of patients with hypoplastic left heart syndrome have resulted in improved outcomes. Over the past few years, numerous modifications to the intraoperative and postoperative management of these patients have been described. It is likely that in combination, these modifications and better understanding of the unique physiology after the Norwood procedure are responsible for decreasing early mortality. This review describes and discusses the current surgical and medical management of patients undergoing first-stage palliation for hypoplastic left heart syndrome and its variants.

The effects of aprotinin on blood product transfusion associated with thoracic aortic surgery requiring deep hypothermic circulatory arrest

OBJECTIVE

To compare the effects of aprotinin on blood product use and postoperative complications in patients undergoing thoracic aortic surgery requiring deep hypothermic circulatory arrest.

DESIGN

A retrospective study.

SETTING

A university hospital.

PARTICIPANTS

Nineteen patients who underwent elective or urgent thoracic aortic surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The total number of units of packed red blood cells, fresh frozen plasma, and platelets was significantly less in the group that received aprotinin (p = 0.01, 0.04, and 0.01). The intraoperative transfusion of packed red blood cells and platelets, collection and retransfusion of cell saver, and postoperative transfusion of fresh frozen plasma were also significantly less in the aprotinin group (p = 0.01, 0.02, 0.01, and 0.05). No patient in either group sustained renal dysfunction or a myocardial infarction. Two patients who had not received aprotinin suffered from chronic postoperative seizures, and one patient who had received aprotinin sustained a perioperative stroke.

CONCLUSIONS

Low-dose aprotinin administration significantly decreases blood product transfusion requirements in the setting of thoracic aortic surgery requiring deep hypothermic circulatory arrest, and it does not appear to be associated with renal or myocardial dysfunction.