A rational approach to wound difficulties after sternotomy: the problem.

One hundred fifty-one patients with mediastinitis after median sternotomy were treated by a single surgeon over a 6-year period. The infections were analyzed in regard to the depth of infection, time of presentation, and the mediastinal defect. Preoperative evaluations included computed tomographic (CT) scans, testing for sternal stability, and the level of contamination. Intraoperative evaluations included bone, inflammatory tissues, Gram stain, and cultures. Treatment options included rewire procedures (20 patients), immediate reconstruction (63 patients), or delayed reconstructions (88 patients). The issues of exposed prosthetic material, right ventricular laceration, long-term intravenous antibiotics, Candida infections, and reexploration of the healed mediastinum after flap reconstruction are discussed. The overall approach to postoperative healing difficulties after sternotomy is examined.

A rational approach to wound difficulties after sternotomy: reconstruction and long-term results.

One hundred fifty-one patients were reconstructed after median stemotomy by a single plastic surgeon over a 6-year period. The treatment included immediate reconstruction (63 patients) and delayed reconstructions (88 patients). Ninety eight percent of the patients had definitive healing at 6 weeks with an overall 30-day mortality of 4 percent. The issues of long-term intravenous antibiotics, perceived skin deficiency, cardiac decompensation, Candida infections, and reexploration of a healed mediastinum after flap reconstruction are discussed. Follow up (4 months to 6 years) of patients treated with reconstruction compared favorably with patients treated with rewiring procedures (20 patients) in regard to strength, chest wall stability, pulmonary function testing, and functional return to hobbies and employment.

Single-stage reoperative repair of chronic type A aortic dissection by means of the arch-first technique.

OBJECTIVE: Management of the enlarged, chronically dissected aorta after previous repair of acute aortic dissection or after a previous cardiac operation may present a formidable technical challenge. Marked enlargement of the proximal descending thoracic aorta precludes safe use of staged procedures, including the elephant trunk technique. METHODS: Sixteen patients with chronic type A aortic dissection (mean age, 56 years) underwent resection of the ascending aorta, the aortic arch, and varying segments of the descending thoracic aorta. We used single-stage replacement, with perfusion of the aortic arch first to minimize the duration of brain ischemia, with a bilateral anterior thoracotomy (clamshell) incision. Eleven patients had undergone previous repair of acute type A dissection. Five patients had type A dissection after aortic valve replacement (2 patients) and coronary artery bypass (3 patients). Marked enlargement of the aorta distal to the left subclavian artery precluded a 2-stage repair. The mean interval between the initial and reoperative procedures was 62 months (range, 5-137 months). RESULTS: There was 1 (6.2%; 70% confidence limits, 0.3%-24.7%) hospital death. Four patients required reoperation for bleeding. One patient required a right ventricular assist device that was successfully removed. Six patients required assisted ventilation for more than 72 hours, and 3 patients required a tracheostomy. All were successfully weaned from ventilatory support. No patient had a stroke or other adverse neurologic outcome. CONCLUSION: The single-stage, arch-first replacement technique is a safe and effective procedure for patients who require extensive reoperations for chronic expanding type A dissection.

Safety and efficacy of hypothermic cardiopulmonary bypass and circulatory arrest for operations on the descending thoracic and thoracoabdominal aorta.

BACKGROUND: Hypothermic cardiopulmonary bypass with circulatory arrest is an important adjunct for operations on the distal aortic arch and the descending thoracic and thoracoabdominal aorta. Its safety and efficacy compared with other techniques (eg, simple aortic clamping, partial cardiopulmonary bypass, and regional hypothermia) are not clearly established. METHODS: One hundred sixty-one patients (ranging from 20 to 83 years old) with descending thoracic or thoracoabdominal aortic disease had resection and graft replacement of the involved aortic segments using hypothermic cardiopulmonary bypass usually with intervals of circulatory arrest (mean interval, 38 minutes). RESULTS: The 30-day mortality rate was 6.2% (10 patients). It was 41% (7 of 17) for patients having emergent operations (rupture or acute dissection) and 2.1% (3 of 144) for all other patients (p < 0.001). The 90-day mortality rate was 11.8% (19 patients). Paraplegia occurred in 4 and paraparesis in 1 of the 156 operative survivors whose lower limb function could be assessed postoperatively (3.2%). Among the 91 survivors with thoracoabdominal aortic disease, early paraplegia occurred in 1 of 33 patients with Crawford type I disease, 0 of 34 with type II disease, and 2 of 24 with type III disease. One patient (type II disease) had development of paraplegia on the tenth postoperative day. None of the 50 patients with aortic dissection experienced paralysis. Renal dialysis was required in 4 (2.5%) of the 157 operative survivors, prolonged inotropic support (> 48 hours) in 17 (11%), reoperation for bleeding in 8 (5%), mechanical ventilation (> 48 hours) in 31 (20%), and tracheostomy in 13 (8%). Three patients (1.9%) sustained a stroke. CONCLUSIONS: Hypothermic cardiopulmonary bypass provides safe and substantial protection against paralysis and renal, cardiac, and visceral organ system failure that equals or exceeds that of other currently used techniques but without the need of other adjuncts.

Sex differences in neurological outcomes and mortality after cardiac surgery: a society of thoracic surgery national database report.

BACKGROUND: The purpose of this study was to evaluate whether women undergoing cardiac surgery are more likely to suffer neurological complications than men and whether these complications could explain, at least in part, their higher perioperative mortality. METHODS AND RESULTS: The Society of Thoracic Surgery National Cardiac Surgery Database was examined for the years 1996 and 1997 to determine the frequency of new neurological events (stroke, transient ischemic attack, or coma) occurring after cardiac surgery. We reviewed clinical information on 416 347 patients (32% women) for whom complete neurological outcome data were available. New neurological events after surgery were higher for women than for men (3.8% versus 2.4%, P=0.001). For the whole group, the 30-day mortality was higher for women than for men (5.7% versus 3.5%, P=0.001), and among those patients who suffered a perioperative neurological event, mortality was also significantly higher for women than men (32% versus 28%, P=0.001). After adjustment for other risk factors (eg, age, history of hypertension and/or diabetes, duration of cardiopulmonary bypass, and other comorbid conditions) by multivariable logistic regression, female sex was independently associated with significantly higher risk of suffering new neurological events after cardiac surgery (OR 1.21, 95% CI 1.14 to 1.28, P=0.001). CONCLUSIONS: Women undergoing cardiac surgery are more likely than men to suffer new perioperative neurological events, and they have higher 30-day mortality when these complications occur. The higher incidence of perioperative neurological complications in women cannot be explained by currently known risk factors.

White matter injury in spinal cord ischemia: protection by AMPA/kainate glutamate receptor antagonism.

BACKGROUND AND PURPOSE: Spinal cord ischemia is a serious complication of surgery of the aorta. NMDA receptor activation secondary to ischemia-induced release of glutamate is a major mechanism of neuronal death in gray matter. White matter injury after ischemia results in long-tract dysfunction and disability. The AMPA/kainate receptor mechanism has recently been implicated in white matter injury. METHODS: We studied the effects of AMPA/kainate receptor blockade on ischemic white matter injury in a rat model of spinal cord ischemia. RESULTS: Intrathecal administration of an AMPA/kainate antagonist, 6-nitro-7-sulfamoyl-(f)-quinoxaline-2, 3-dione (NBQX), 1 hour before ischemia reduced locomotor deficit, based on the Basso-Beattie-Bresnahan scale (0=total paralysis; 21=normal) (sham: 21+/-0, n=3; saline: 3.7+/-4.5, n=7; NBQX: 12. 7+/-7.0, n=7, P<0.05) 6 weeks after ischemia. Gray matter damage and neuronal loss in the ventral horn were evident after ischemia, but no difference was noted between the saline and NBQX groups. The extent of white matter injury was quantitatively assessed, based on axonal counts, and was significantly less in the NBQX as compared with the saline group in the ventral (sham: 1063+/-44/200x200 microm, n=3; saline: 556+/-104, n=7; NBQX: 883+/-103, n=7), ventrolateral (sham: 1060+/-135, n=3; saline: 411+/-66, n=7; NBQX: 676+/-122, n=7), and corticospinal tract (sham: 3391+/-219, n=3; saline: 318+/-23, n=7; NBQX: 588+/-103, n=7) in the white matter on day 42. CONCLUSIONS: Results indicate severe white matter injury in the spinal cord after transient ischemia. NBQX, an AMPA/kainate receptor antagonist, reduced ischemia-induced white matter injury and improved locomotor function.

Aortic allografts and pulmonary autografts for replacement of the aortic valve and aortic root.

BACKGROUND: Extensive experience has accumulated with the use of aortic and pulmonary autografts for replacement of the aortic valve and the aortic root. Three general techniques for insertion have been used: subcoronary (free-hand) valve implantation, mini- or inclusion-root implantation, and aortic root replacement. Thirty-day mortality for elective operations with all of these techniques has not exceeded 5%. Thromboembolic episodes have been rare, and endocarditis has occurred infrequently. Early hemodynamic performance has been excellent, without significant gradients or valve regurgitation in the majority of patients. METHODS AND RESULTS: Progressive aortic regurgitation has been observed with continued follow-up, and is the most important complication of both types of valves. Leaflet failure and technical problems are the major causes of reoperation for patients receiving aortic allografts. There is some evidence to suggest that the prevalence of these complications is lower with the root replacement technique than with the intraaortic implantation methods. CONCLUSIONS: Reoperation for regurgitation of the neoaortic valve is the major complication of the pulmonary autograft procedure. The incidence of reoperation appears to be lowest with the root replacement technique. Certain conditions (acute rheumatic fever, juvenile rheumatoid arthritis, systemic lupus, ankylosing spondylitis, Libman-Sachs endocarditis, and possibly a dilated aortic root) may be contraindications to the use of a pulmonary autograft. Reoperation on the pulmonary allograft that is used to replace the autograft may be necessary in up to 20% of patients at 20 years.

Hypothermic cardiopulmonary bypass for spinal cord protection: rationale and clinical results.

BACKGROUND: Hypothermic cardiopulmonary bypass with or without circulatory arrest has been used successfully for the treatment of complex aneurysms of the descending thoracic and thoracoabdominal aorta. Hypothermia has a protective effect on spinal cord function, and its use has been associated with a low incidence of paraplegia in traditionally high-risk patients. Experimentally, the protective effect of hypothermia has been related to amelioration of excitotoxic injury by reduction of neurotransmitter release and to inhibition of delayed apoptotic cell death. METHODS: During a 12-year period, 114 patients with descending thoracic or thoracoabdominal aortic disease underwent replacement of the involved aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest. RESULTS: The hospital mortality was 8% (9 patients). Paraplegia occurred in 2 and paraparesis in 1 of the 108 patients whose lower limb function was assessed postoperatively (2.8%). None of 40 patients with aortic dissection and none of the last 81 patients in the series developed paralysis. CONCLUSIONS: Our experience with hypothermic cardiopulmonary bypass and circulatory arrest confirms that hypothermia provides substantial protection against paraplegia, and it allows complex operations on the descending thoracic and thoracoabdominal aorta to be performed with acceptable mortality.

Obstacles to early discharge after cardiac surgery.

CONTEXT: Cardiovascular disease and cardiac surgery, in particular, are associated with a large expenditure of healthcare resources. Identifying the factors that affect length of stay for patients hospitalized for cardiac surgery and ways to safely and effectively shorten stays could have significant impact on healthcare costs. OBJECTIVE: To identify obstacles to and the effects of early discharge on outcome after cardiac surgery. STUDY DESIGN: A prospective approach using a protocol consisting of modifying anesthesia, limiting the use of postoperative narcotics, early extubation, and early mobilization, with a goal of discharge at < 5 days. PATIENTS AND METHODS: The study group consisted of 422 consecutive patients (age range 15-89 years, 65% males): coronary artery bypass graft (CABG) (n = 290), valve procedures (n = 54), and CABG + valve procedures (n = 78). The discharge criteria included hemodynamic stability, normal bowel function, independence in activities of daily living, absence of fever, and no incision problems. RESULTS: Predictors of prolonged postoperative stay were prolonged intensive care unit stay (P < 0.0001), postoperative atrial fibrillation (P = 0.0006), preoperative congestive heart failure (P = 0.002), combined CABG and valve procedure (P = 0.005), prolonged ventilator support (P = 0.01), increasing age (P = 0.012), history of peripheral vascular disease (P = 0.02), and female gender (P = 0.025). The 30-day readmission rate for the early discharge group was 7.8% vs 16.2% for the late discharge group (P = 0.01). The mortality rate for the entire group was 3.3%.

Atherosclerosis of the ascending aorta is an independent predictor of long-term neurologic events and mortality.

OBJECTIVES: This study was undertaken to determine whether atherosclerosis of the ascending aorta is a predictor of long-term neurologic events and mortality. BACKGROUND: Atherosclerosis of the thoracic aorta has been recently considered a significant predictor of neurologic events and peripheral embolism, but not of long-term mortality. METHODS: Long-term follow-up (a total of 5,859 person-years) was conducted of 1,957 consecutive patients > or =50 years old who underwent cardiac surgery. Atherosclerosis of the ascending aorta was assessed intraoperatively (epiaortic ultrasound) and patients were divided into four groups according to severity (normal, mild, moderate or severe). Carotid artery disease was evaluated (carotid ultrasound) in 1,467 (75%) patients. Cox proportional-hazards regression analysis was performed to assess the independent effect of predictors on neurologic events and mortality. RESULTS: A total of 491 events occurred in 472 patients (neurologic events 92, all-cause mortality 399). Independent predictors of long-term neurologic events were: hypertension (p = 0.009), ascending aorta atherosclerosis (p = 0.011) and diabetes mellitus (p = 0.015). The independent predictors of mortality were advanced age (p < 0.0001), left ventricular dysfunction (p < 0.0001), ascending aorta atherosclerosis (p < 0.0001), hypertension (p = 0.0001) and diabetes mellitus (p = 0.0002). There was >1.5-fold increase in the incidence of both neurologic events and mortality as the severity of atherosclerosis increased from normal-mild to moderate, and a greater than threefold increase in the incidence of both as the severity of atherosclerosis increased from normal-mild to severe. CONCLUSIONS: Atherosclerosis of the ascending aorta is an independent predictor of long-term neurologic events and mortality. These results provide additional evidence that in addition to being a direct cause of cerebral atheroembolism, an atherosclerotic ascending aorta may be a marker of generalized atherosclerosis and thus of increased morbidity and mortality.

Hypothermic circulatory arrest and hypothermic perfusion for extensive disease of the thoracic and thoracoabdominal aorta.

BACKGROUND: Hypothermic cardiopulmonary bypass with or without an interval of circulatory arrest has been evaluated for the treatment of complex aortic disease of the descending thoracic and thoracoabdominal aorta. Hypothermia has a protective effect on spinal cord function, and its use should reduce the incidence of paraplegia and paraparesis in traditionally high-risk patients. Experimentally, the protective effect of hypothermia has been related to amelioration of excitotoxic injury by reduction of neurotransmitter release and to inhibition of delayed apoptopic cell death. METHODS: During a 12-year period, 114 patients with descending thoracic or thoracoabdominal aortic disease underwent replacement of the involved aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest. The mean age of the patients was 60 years (range 22 to 79 years). Acute or chronic dissection was present in 40 patients (35%). Sixty-four patients (56%) had Crawford Types I, II, or III thoracoabdominal aneurysms. RESULTS: The hospital mortality was 8% (9 patients). Paraplegia occured in 2 and paraparesis in 1 of the 108 patients whose lower limb function was assessed postoperatively (2.8%). None of 40 patients with aortic dissection and none of the last 81 patients in the series developed paralysis. One patient developed renal failure that required dialysis. CONCLUSIONS: Our experience with hypothermic cardiopulmonary bypass and circulatory arrest confirms that hypothermia provides substantial protection against spinal cord ischemic injury. It allows complex operations on the descending thoracic and thoracoabdominal aorta to be performed with acceptable mortality, a low incidence of renal failure, and an incidence of other complications that does not exceed that reported with other techniques.

Single-stage extensive replacement of the thoracic aorta: the arch-first technique.

BACKGROUND: Single-stage extensive replacement of the thoracic aorta usually involves a period of circulatory arrest with performance of the graft-to-lower descending thoracic aorta anastomosis before performing the anastomosis to the arch vessels. To minimize the period of brain ischemia and reduce the potential for neurologic injury, we developed an alternative technique. METHODS: In 6 patients with extensive aneurysms involving the entire thoracic aorta, exposure was obtained via a bilateral thoracotomy in the anterior fourth intercostal space with transverse sternotomy. A 10-mm graft was anastomosed to the aortic graft, opposite the site of the planned anastomosis to the arch vessels. During a single period of circulatory arrest (34-46 minutes), the aortic graft was attached to a cuff of aorta containing the arch vessels. The graft was then clamped on either side, and the arch was perfused with cold blood for 20 to 36 minutes. After the distal aortic anastomosis was completed, antegrade perfusion was established via the 10-mm graft. The proximal aortic anastomosis was performed last. RESULTS: No patient sustained a permanent neurologic deficit. All 6 patients were discharged from the hospital. CONCLUSIONS: The "arch-first" technique, combined with a bilateral transverse thoracotomy, allows expeditious replacement of the thoracic aorta with an acceptable interval of hypothermic circulatory arrest and minimizes the risk of retrograde atheroembolism by establishing antegrade perfusion.

Atherosclerosis of the ascending aorta is a predictor of renal dysfunction after cardiac operations.

OBJECTIVES: Renal dysfunction occurring after cardiac operations has been attributed to various factors, but the importance of an atherosclerotic thoracic aorta has not been previously evaluated. The purpose of this study was to identify predictors of postoperative renal dysfunction (50% or more increase from preoperative values) and to evaluate the importance of atherosclerosis of the ascending aorta as a predictor of this complication. METHODS: Nine hundred seventy-eight consecutive patients, 50 years of age and older with normal preoperative renal function (serum creatinine level of 1.5 mg/dL or less), who were scheduled to undergo cardiac surgery were prospectively evaluated. Atherosclerosis of the ascending aorta was assessed during the operation (with epiaortic ultrasound), and patients were divided into 3 groups according to its severity (normal-to-mild, moderate, and severe). RESULTS: Univariate predictors of renal dysfunction at postoperative day 1 were atherosclerosis of the ascending aorta (P <. 045) and postoperative low cardiac output (P =.05); at postoperative day 6 they were atherosclerosis of the ascending aorta (P <.0001), postoperative low cardiac output (P <.0001), advanced age (P =.001), decreased preoperative left ventricular function (P =.01), and female gender (P =.03). Multivariate analysis showed that atherosclerosis of the ascending aorta (odds ratio, 3.06; P =.04) was the only independent predictor of postoperative renal dysfunction at day 1 and that postoperative low cardiac output (odds ratio, 4.83; P <.0001), atherosclerosis of the ascending aorta (odds ratio, 2.13; P =.0006), and preoperative left ventricular dysfunction (odds ratio, 1.48; P =.028) were independent predictors of postoperative renal dysfunction at day 6. CONCLUSIONS: An atherosclerotic ascending aorta is an important predictor of postoperative renal dysfunction, possibly because atheroembolism to the kidneys occurs in the perioperative period (ie, during surgical manipulation of an atherosclerotic aorta) or because the diseased aorta may be a marker of widespread atherosclerotic disease that may predispose to perioperative renal dysfunction.

Surgical management of the severely atherosclerotic ascending aorta during cardiac operations.

Severe atherosclerosis of the ascending aorta is associated with an increased incidence of stroke after cardiac surgery. Direct intraoperative epiaortic scanning is a rapid and accurate means for detection of ascending aortic atherosclerosis. When severe atheromatous disease is detected, graft replacement of the ascending aorta is our preferred method of management. During an 11-year period, 81 patients (mean age 71 years) who underwent coronary artery bypass were found to have severe ascending aortic atherosclerosis by epiaortic scanning. Using hypothermic circulatory arrest, 80 patients underwent partial (5) or complete (75) ascending aortic replacement. One patient underwent resection of a protruding aortic atheroma. In addition to partial or total replacement of the ascending aorta, 34 patients had replacement of the aortic arch, 19 had a valve replacement, and 6 had carotid endarterectomy. The 30-day mortality was 8.6% (7 patients). Four patients (4.9%) sustained perioperative strokes and 2 (2.5%) sustained transient perioperative ischemic neurological deficits. The 3-year survival rate was 40%. There was one stroke 4 months postoperatively that eventually led to late death. Elective resection and graft replacement of the severely atherosclerotic ascending aorta using hypothermic circulatory arrest in patients undergoing cardiac operations is a safe procedure, associated with an acceptable incidence of postoperative stroke. The procedure may provide long-term protection from subsequent embolic cerebral vascular events. However, long-term survival has been disappointing and is primarily related to generalized atherosclerosis.

MRI-radiofrequency tissue tagging in patients with aortic insufficiency before and after operation.

BACKGROUND: Magnetic resonance imaging tissue tagging is a relatively recent methodology that describes ventricular systolic function in terms of intramyocardial ventricular deformation. Because the analysis involves the use of many intramyocardial points to describe systolic deformation, it is theoretically more sensitive at describing subtle differences in regional myocardial fiber shortening when compared with conventional measures of ventricular function such as wall thickening. The objectives of this study were (1) to define sensitive indices of ventricular systolic deformation to assist the clinician in the surgical evaluation of patients with aortic insufficiency, and (2) to quantify differences in regional systolic deformation before and after surgery for aortic insufficiency. METHODS: Magnetic resonance imaging with tissue tagging was performed on 10 normal volunteers and 8 patients with chronic severe aortic insufficiency. Follow-up postoperative studies (5.4+/-1.1 months) were obtained in 6 patients who underwent Ross procedure (1 patient), David procedure (1), and St. Jude aortic valve replacement (4). RESULTS: There was no significant difference in fractional area change, overall circumferential shortening, or overall radial thickening among the normal group, the preoperative aortic insufficiency group, or the postoperative aortic insufficiency group. However, on a regional basis, there was a decrease in posterior wall circumferential strains in the postoperative aortic insufficiency group (29%+/-13% preoperative aortic insufficiency (n=6) versus 24%+/-12% postoperative aortic insufficiency (n=6), p=0.02). CONCLUSIONS: On regional analysis, there was a small but significant decrease in posterior wall circumferential shortening after operation. Magnetic resonance imaging tissue tagging is a sensitive and clinically applicable method of quantifying regional ventricular wall function before and after intervention for aortic insufficiency.

Profound hypothermia for spinal cord protection in operations on the descending thoracic and thoracoabdominal aorta.

Elective hypothermic cardiopulmonary bypass with or without circulatory arrest has been used successfully for the treatment of complex aneurysms of the descending thoracic and thoracoabdominal aorta. Hypothermia has a protective effect on spinal cord function, and its use has been associated with a low incidence of paraplegia in traditionally high-risk patients. In our series, 96 consecutive patients underwent resection and graft replacement of diseased aortic segments of the distal aortic arch, the descending thoracic aorta, or the thoracoabdominal aorta. Thirty-day mortality was 7.3%, and the incidence of spinal cord ischemic injury was 3.4%. Our experience with hypothermic cardiopulmonary bypass and circulatory arrest confirms the safety and efficacy of the technique for operations on the descending thoracic and thoracoabdominal aorta.