Taek Yeon Lee

Cerebrospinal Fluid Drainage During Thoracic Aortic Repair: Safety and Current Management

BACKGROUND The benefit of cerebrospinal fluid (CSF) drainage during thoracic aortic repair has been established. Few studies, however, report management and safety of CSF drainage. METHODS Between September 1992 and August 2007, 1,353 repairs of the thoracic aorta were performed, with 82% using CSF drainage. The CSF drainage was not used in cases of rupture, acute trauma, infection, or prior paraplegia. Thirty-one percent (76 of 246) of patients without CSF drainage were repaired prior to standardized use. All drains were inserted by cardiovascular anesthesia staff. Repairs were performed using distal aortic perfusion with heparinization. Early management involved free drainage to maintain CSF pressure less than 10 mm Hg, but was later modified to limit CSF drainage unless neurologic deficit occurred. RESULTS Cerebrospinal fluid drainage was technically achieved in 99.8% (1,105 of 1,107) of cases. The CSF catheter-related complications occurred in 1.5% (17 of 1,107) of patients. No spinal hematomas were observed. The CSF leaks with spinal headache, CSF leak without spinal headache, spinal headache, intracranial hemorrhage, catheter fracture, and meningitis occurred in 6 (0.54%), 1 (0.1%), 2 (0.2%), 5 (0.45%), 1 (0.1%), and 2 (0.2%) cases, respectively. Mortality from subdural hematoma was 40% (2 of 5), and from meningitis was 50% (1 of 2). Spinal headaches resolved with conservative management. All CSF leaks resolved, but 71% (5/7) required blood patches. Since implementation of a limited CSF drainage protocol, no subdural hematomas have been observed. CONCLUSIONS Cerebrospinal fluid drainage for thoracic aortic repairs can be performed safely with excellent technical success. Perioperative management of CSF drains requires diligent monitoring and judicious drainage. Standardizing CSF management may be beneficial.

Ascending and Transverse Aortic Arch Repair The Impact of Retrograde Cerebral Perfusion

Background— The benefit of retrograde cerebral perfusion (RCP) with profound hypothermic circulatory arrest has been subject to much debate. We examined our experience with ascending and transverse arch repairs to determine the impact of retrograde cerebral perfusion on stroke and mortality. Methods and Results— Between August 1991 and June 2007, we performed 1107 repairs of the ascending and transverse aortic arch. RCP was used in 82% of cases (907 of 1107). Sixty-two percent were men (682 of 1107); median age was 64 years (range, 16 to 93 years). Perioperative variables were evaluated using univariate and multivariable analysis for mortality and stroke. Thiry-day mortality was 10.4% (115 of 1107). Stroke occurred in 2.8% (31 of 1107) of patients. Univariate risk factors for mortality were increasing age (P<0.0001), history of coronary artery disease (P=0.02), previous coronary artery bypass (P=0.02), emergency status (P<0.0001), acute dissection (P=0.02), rupture (P=0.0001), preoperative glomerular filtration rate, bypass time (P<0.0001), crossclamp time (P<0.007), RCP time (P<0.0001), and packed red blood cell transfusions (P=0.0001). Univariate risk factors for stroke included emergency status (P<0.02), cerebrovascular disease (P<0.02), and crossclamp time (P<0.04). Independent risk factors for mortality were glomerular filtration rate <90 mL/min (P=0.0004), emergency status (P=0.006), rupture (P=0.004), cardiopulmonary bypass time >120 minutes (P<0.04), and packed red blood cell transfusions (P=0.0002). Risk factors for stroke were emergency status (P<0.009) and hypertension (P<0.05). RCP was protective against mortality and stroke. Conclusions— The use of RCP with profound hypothermic circulatory arrest was associated with a reduction in mortality and stroke. The use of RCP remains warranted during repairs of the ascending and transverse aortic arch.

Outcomes of Acute Type A Aortic Dissection After Previous Cardiac Surgery

BACKGROUND Reports on outcomes of acute type A aortic dissection (ATAAD) repair after previous cardiac surgery (PCS) are few. Some suggest no difference in mortality while others note decreased risk of free rupture due to adhesions. We analyzed our experience of ATAAD after PCS. METHODS Between January 1992 and March 2009 we repaired 330 patients with ATAAD. Of these, 49 (15%) patients had PCS: coronary artery bypass in 30 (61%), aortic valve replacement in 8 (16%), coronary artery bypass/aortic valve replacement in 5 (10%), aortic valve replacement-mitral repair in 1 (2%), aortic valve replacement-tricuspid repair in 1 (2%), and others in 4 (9%) patients. The ATAAD patients with and without PCS (primary) were compared. RESULTS The PCS group was older (63 vs 58 years, p < 0.02), more frequently men (82% vs 67%, p < 0.04), and less likely to have aortic insufficiency (30% vs 47%, p < 0.05). Otherwise, the PCS group did not differ in clinical presentation, with similar malperfusion and tamponade. Operative procedures did not differ between groups except for repair of pulmonary artery fistula (4% vs 0%, p < 0.03), more use of Cabrol shunt (18% vs 3%), p < 0.03), and more frequent need for mechanical cardiac support in the PCS group (8% vs 3.6%, p < 0.04). The PCS group suffered more strokes (10% vs 2.5%, p < 0.03), temporary neurologic deficits (24% vs 10%, p < 0.007), and higher hospital mortality (31% vs 13.8%, p < 0.007) than the no-PCS group. CONCLUSIONS Patients with ATAAD after PCS exhibited similar risks for malperfusion, hypotension, and cardiac tamponade. This suggests that adhesions formed after PCS do not eliminate the risk of cardiac tamponade from aortic rupture. Although results from surgical repair are acceptable, justifying timely repair, mortality still remains higher than without prior history of cardiac surgery.

Acute Type A Intramural Hematoma Analysis of Current Management Strategy

Background— Management of acute type A intramural hematoma (IMH) remains controversial, varying from immediate surgery to medical management only. Conversion to typical dissection remains a concern. We analyzed our experience managing acute type A IMH. Methods and Results— Between October 1999 and May 2008, 251 patients with acute type A aortic dissection were treated, including 36 (14.3%) with type A IMH. Seven IMH patients (19%) were repaired immediately, 28 (80%) managed initially with optimal medical management and eventual repair and 1 (3%) with medical management only. End points analyzed were early mortality and conversion to typical dissection (flow in the false lumen of the ascending aorta). Time (hours) from onset of symptoms defined initiation of IMH. Early mortality for acute type A IMH was 8.3% (3/36): 14.3% (1/7) with immediate repair and 7.1% (2/28) when optimal medical management with eventual repair was undertaken (P=0.69). The 1 medically managed Asian patient survived with resolution of the IMH. Conversion to type A IMH to typical dissection occurred in 33% (12/36) of cases. No conversions were observed within 72 hours. Aortic diameter did not predict conversion. In actuarial analysis among the initially medically managed group with eventual repair, the hazard conversion to typical dissection increased significantly at 8 days from the onset of symptoms (P<0.05). Conclusions— Despite optimal medical management, conversion of type A IMH to typical dissection still remains a concern, with the most significant risk beyond 8 days. In our patient population, timely surgical repair is recommended.

Analysis of Ascending and Transverse Aortic Arch Repair in Octogenarians

BACKGROUND Increasing numbers of older patients are requiring complex thoracic aortic surgery. This retrospective study analyzed early and late outcomes after ascending and transverse arch surgery using hypothermic circulatory arrest (HCA). METHODS Between January 1991 and December 2006, 779 patients requiring HCA were treated. Outcomes are reported by age group: group 1, 80 years or more (37, 4.8%); and group 2, less than 80 years (742, 95.2%). Univariate and multivariate analyses were used to identify risk factors for morbidity and mortality. RESULTS Early mortality and stroke did not differ between groups. Thirty-day mortality was13.5% (5 of 37) in group 1 and 10% (78 of 742) in group 2 (p = 0.57). Stroke occurred in 8% (3 of 37) of group 1 patients and 2.7% (20 of 742) of group 2 patients (p = 0.09). Predictors of stroke were prior stroke (p = 0.003) and pump time (p = 0.02). Predictors of early mortality were low glomerular filtration rate (p = 0.0001), long cardiopulmonary bypass time (p = 0.0001), and emergent repair (p = 0.0009). Retrograde cerebral perfusion was protective against stroke (p = 0.0001) and reduced early mortality (p = 0.02). Age was not a predictor of stroke (p = 0.12) or early mortality (p = 0.39). Survival in group 1 compared with the age-matched US population at 1 year was 56% versus 86% (p = 0.02); at 2 years, 48% versus 76% (p = 0.03); at 5 years, 36% versus 48% (not significant); and at 10 years, 20% versus 20%. CONCLUSIONS Ascending and aortic arch surgery in octogenarians involving profound HCA resulted in reasonable morbidity and short- and long-term mortality rates. The use of profound HCA for aortic surgery remains warranted in octogenarians.

Repair of ascending and transverse aortic arch

OBJECTIVES This is a report to update our experience with repairs of the ascending and transverse arch, with an emphasis on the protective measures, including retrograde cerebral perfusion and blood flow and neurologic monitoring. METHODS Retrospective data were collected from January 1991 to February 2010, and analysis was conducted on 1193 patients who had aneurysms involving the ascending aorta and arch. RESULTS The 30-day mortality rate was 9.3%, but with a normal glomerular filtration rate, the mortality rate was 3%. In univariate analysis of the risk factors for death, the factors were advancing age of greater than 72 years (mortality, 14.8%; P = .002), the presence of coronary artery disease (mortality, 13.5%; P = .02), aortic pathology of acute dissection (mortality, 13.9%; P = .004), the emergency nature of the operation (mortality, 16.1%; P = .0001), and renal function in the lowest 3 quartiles of glomerular filtration rate (mortality, 6.9%, 10%, and 18.3%; P = .03, .0005, and .0001, respectively, with decreasing glomerular filtration rate). The highest quartile for pump time (>179 minutes) had a mortality rate of 18.1% (P = .0001). The overall stroke rate was 3%. In univariate analysis of risk factors for stroke, the stroke rate was 2.8% with and 4.2% without retrograde cerebral perfusion (P = .30), but when circulatory arrest time exceeded 40 minutes, the stroke rate was 1.7% with and 30% without retrograde cerebral perfusion (P = .002). Risk factors included age greater than 62 years (stroke rate, 4%; P = .04), hypertension (stroke rate, 3.7%; P = .03), emergency operations (stroke rate, 4.9%; P = .04), and glomerular filtration rate of less than 56 (stroke rate, 4.3%; P = .05). In multiple logistic regression for risk factors for stroke, age was associated with an odds ratio of 1.04 (P = .008), and emergency conditions had an odds ratio of 2.17 (P = .03). CONCLUSIONS Retrograde cerebral perfusion was associated with a trend toward a reduced incidence of hospital mortality and, in patients receiving prolonged hypothermic circulatory arrest, a reduced incidence of stroke.

Mitral valve replacement with or without a concomitant Maze procedure in patients with atrial fibrillation

Background Although the Maze procedure is regarded as the most effective way to restore sinus rhythm in patients with chronic atrial fibrillation (AF), it remains unclear whether this procedure offers long-term clinical benefits in patients undergoing mechanical valve replacement. Methods and results Between 1999 and 2007, 402 patients with AF-associated mitral valve (MV) disease underwent MV replacement with a mechanical prosthesis. Of these patients, 159 underwent valve replacement plus the Maze procedure, whereas 243 received valve replacement alone. The composite end points of cardiac death and cardiac-related morbidities were compared in these two groups using the inverse-probability-of-treatment-weighted method. At a median follow-up time of 63.1 months (range 0.2–123.9 months), patients who had undergone the Maze procedure were at significantly lower risk of thromboembolic events (hazard ratio (HR)=0.26, 95% confidence interval (CI) 0.07 to 0.95; p=0.041) and were at comparable risk of death (HR=0.96, 95% CI 0.44 to 2.07; p=0.907) and cardiac death (HR=1.26, 95% CI 0.53 to 3.01; p=0.598) compared with patients who underwent MV replacement alone. The composite risk of death or major events was lower in the Maze procedure group (HR=0.64, 95% CI 0.38 to 1.08; p=0.093). Conclusions Compared with MV replacement alone, the addition of the Maze procedure was associated with a reduction in thromboembolic complications and better long-term event-free survival in patients with AF undergoing mechanical MV replacement. Prospective randomised data are necessary to confirm the findings of this study.

The impact of sequential versus single anastomoses on flow characteristics and mid-term patency of saphenous vein grafts in coronary bypass grafting

OBJECTIVE To assess the influence of bypass grafting technique on the flow characteristics and mid-term patency of saphenous vein coronary bypass grafts. METHODS In the present study, 309 patients who underwent either sequential (group A, N = 84 grafts) or individual (group B, N = 244 grafts) saphenous vein coronary bypass grafting between February 2002 and September 2007 were investigated. Individual bypassing only was performed in 212 patients, and sequential bypassing only was performed in 78 patients. The remaining 19 patients received both. A total of 436 distal anastomoses were performed with 328 saphenous vein grafts. The intraoperative flow characteristics and the graft patency were assessed with the transit time flow meter and serial multi-detector computed tomography coronary angiograms, respectively. RESULTS Group A showed a higher mean flow compared with group B at 49.4 ± 27.4 mL/min versus 37.1 ± 20.1 mL/min, respectively (P = .001). The mean flow increased linearly as the number of anastomoses increased per graft (P < .001). Graft patency at 3 years was 93.3% ± 3.4% in group A and 86.5% ± 3.1% in group B (P = .048). After adjustment for baseline characteristics, group A showed a tendency for superior mid-term patency than group B (hazard ratio 0.362; 95% confidence interval, 0.129-1.017; P = .0538). CONCLUSIONS Sequential bypass grafts were associated with higher mean flows and superior mid-term patency compared with individual grafts. These findings suggest the more favorable results of sequential bypass grafting to be attributed to the enhanced flow hemodynamics.

Repair of retrograde type A aortic dissection after thoracic endovascular aortic aneurysm repair using the modified elephant trunk technique

We present a case of retrograde type A aortic dissection after thoracic endovascular stenting for acute type B aortic dissection. We describe the specifics of our surgical technique and provide a brief review of the literature.