Effects of institutional volumes on operative outcomes for aortic root replacement in North America.

OBJECTIVES: Hospital procedure volume has been strongly associated with postoperative mortality for a number of complex cardiovascular procedures. Although not yet described, a similar relationship might be expected for surgical procedures involving the aortic root and/or ascending aorta. The present study sought to evaluate the relationship between the volume of aortic root replacement procedures and the operative results for centers in North America. METHODS: Patient-level data for 13,358 elective aortic root and aortic valve-ascending aortic procedures performed from 2004 through 2007 were obtained from 741 North American hospitals participating in the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Marginal logistic regression modeling was used for risk adjustment. The hospital procedure volume was the primary predictor variable. Patient demographics, comorbid conditions, and operative characteristics were included as the predictor variables for risk adjustment. The primary outcome measures included unadjusted operative mortality and adjusted odds ratio for mortality. RESULTS: The preoperative patient risk profiles were similar at all center volume levels, and the overall unadjusted operative mortality was 4.5%. The unadjusted operative mortality increased with decreasing case volume, from 3.4% in the highest volume centers to 5.8% in the lowest volume centers. Whether hospital volume was assessed as a categorical or continuous variable, its relationship with the adjusted odds ratio for mortality was nonlinear. A negative association was seen between the hospital procedural volume and adjusted odds ratio for mortality (P < .001) that was most pronounced among hospitals performing fewer than 30 to 40 procedures annually. CONCLUSIONS: Patients undergoing elective aortic root or combined aortic valve-ascending aortic surgery at North American hospitals that performed fewer than 30 to 40 of such procedures annually have greater risk-adjusted mortality than those undergoing surgery in higher volume hospitals. Causative factors for this inverse association between hospital volume and mortality deserve additional analysis.

Risk-adjusted survival after tissue versus mechanical aortic valve replacement: a 23-year assessment.

BACKGROUND AND AIM OF THE STUDY: Detailed analyses of risk-adjusted outcomes after mitral valve surgery have documented significant survival decrements with tissue valves at any age. Several recent studies of prosthetic aortic valve replacement (AVR) also have suggested a poorer performance of tissue valves, although analyses have been limited to small matched series. The study aim was to test the hypothesis that AVR with tissue valves is associated with a lower risk-adjusted survival, as compared to mechanical valves. METHODS: Between 1986 and 2009, primary isolated AVR, with or without coronary artery bypass grafting (CABG), was performed with currently available valve types in 2148 patients (1108 tissue valves, 1040 mechanical). Patients were selected for tissue valves to be used primarily in the elderly. Baseline and operative characteristics were documented prospectively with a consistent variable set over the entire 23-year period. Follow up was obtained with mailed questionnaires, supplemented by National Death Index searches. The average time to death or follow up was seven years, and follow up for survival was 96.2% complete. Risk-adjusted survival characteristics for the two groups were evaluated using a Cox proportional hazards model with stepwise selection of candidate variables. RESULTS: Differences in baseline characteristics between groups were (tissue versus mechanical): median age 73 versus 61 years; non-elective surgery 32% versus 28%; CABG 45% versus 35%; median ejection fraction 55% versus 55%; renal failure 6% versus 1%; diabetes 18% versus 7% (p<0.01). Unadjusted Kaplan-Meier survival was significantly lower with tissue than mechanical valves; however, after risk adjustment for the adverse profiles of tissue valve patients, no significant difference was observed in survival after tissue or mechanical AVR. Thus, the hypothesis did not hold, and risk-adjusted survival was equivalent, of course qualified by the fact that selection bias was evident. CONCLUSION: With selection criteria that employed tissue AVR more frequently in elderly patients, tissue and mechanical valves achieved similar survival characteristics across the spectrum of patient risk. Further studies of the relative outcomes of mechanical versus tissue valves across the spectrum of patient age seem indicated.

Does method of sternal repair influence long-term outcome of postoperative mediastinitis?

BACKGROUND: Post-sternotomy mediastinitis reduces survival after cardiac surgery, potentially further affected by details of mediastinal vascularized flap reconstruction. The aim of this study was to evaluate survival after different methods for sternal reconstruction in mediastinitis. METHODS: Two hundred twenty-two adult cardiac surgery patients with post-sternotomy mediastinitis were reviewed. After controlling infection, often augmented by negative pressure therapy, muscle flap, omental flap, or secondary closure was performed. Outcomes were reviewed and survival analysis was performed. RESULTS: Baseline characteristics were similar. In-hospital mortality (15.7%) did not differ between groups. Secondary closure was correlated with negative pressure therapy and reduced length hospital of stay. Recurrent wound complications were more common with muscle flap repair. Survival was unaffected by sternal repair technique. By multivariate analysis, heart failure, sepsis, age, and vascular disease independently predicted mortality, while negative pressure therapy was associated with survival. CONCLUSIONS: Choice of sternal repair was unrelated to survival, but mediastinal treatment with negative pressure therapy promotes favorable early and late outcomes.

The role of intrathoracic free flaps for chronic empyema.

BACKGROUND: The management of chronic empyema associated with a bronchopleural fistula can be a particularly challenging problem. Successful eradication may not occur without interposition of healthy vascularized tissue. Pedicled muscle flaps for coverage on the thorax have been well described. However, secondary to trauma or previous surgical procedures, a pedicle flap may not be sufficiently sized or available. Free tissue transfer is an attractive option to provide the appropriate vascularized tissue. METHODS: Six patients with chronic empyema-bronchopleural fistulae were reconstructed with 4 rectus abdominis myocutaneous and 2 gracilis muscle flaps. The choice of recipient vessels was dictated by existing local anatomy but included intercostal, thoracodorsal, thoracoacromial, azygous, and circumflex humeral vessels. One flap required interposition saphenous vein grafts for both artery and vein. RESULTS: Patient follow-up ranged from 2 to 14 years. There were no episodes of flap loss or postoperative mortality. Empyema resolution without recurrent bronchopleural fistula was achieved in all patients. CONCLUSIONS: Free tissue transfer is an excellent option for vascularized tissue interposition in patients who are not candidates for pedicled muscle transfer. Multiple potential recipient vessels provide tremendous versatility, arguing for early consideration of free tissue transfer.

Midterm results with thoracic endovascular aortic repair for chronic type B aortic dissection with associated aneurysm.

OBJECTIVE: Thoracic endovascular aortic repair for chronic type B aortic dissection with associated descending thoracic aneurysm remains controversial. Concerns include potential ischemic complications due to branch vessel origin from the chronic false lumen and continued retrograde false lumen/aneurysm sac pressurization via fenestrations distal to implanted endografts. The present study examines midterm results with thoracic endovascular aortic repair for chronic (>2 weeks) type B aortic dissection with associated aneurysm to better understand the potential role of thoracic endovascular aortic repair for this condition. METHODS: Between March 2005 and December 2009, 51 thoracic endovascular aortic repair procedures were performed at a single institution for management of chronic type B dissection. The indication for thoracic endovascular aortic repair was aneurysm in all cases. A subset of 7 patients (14%) underwent placement of the EndoSure wireless pressure measurement system (CardioMEMS, Inc, Atlanta, Ga) in the false lumen adjacent to the primary tear for monitoring aneurysm sac/false lumen pulse pressure after thoracic endovascular aortic repair. RESULTS: Mean patient age was 57±12 years (range, 30-82 years); 14 patients (28%) were female. Mean aortic diameter was 6.2±1.4 cm. There were no in-hospital/30-day deaths, strokes, or permanent paraplegia/paresis. There were no complications related to compromise of downstream branch vessels arising from the false lumen. Two patients (3.9%) who had preexisting ascending aortic dilation had retrograde acute type A aortic dissection; both were repaired successfully. Median postoperative length of stay was 4 days. Mean follow-up is 27.0±16.5 months (range, 2-60 months). Actuarial overall survival is 77.7% at 60 months with an actuarial aorta-specific survival of 98% over this same time period. Actuarial freedom from reintervention is 77.3% at 60 months. All patients with the EndoSure wireless pressure measurement system exhibited a decrease in aneurysm sac/false lumen pulse pressure indicating a depressurized false lumen. The aneurysm sac/false lumen pulse pressure ratio decreased from 52%±27% at the predischarge measurement to 14%±5% at the latest follow-up reading (P=.029). CONCLUSIONS: Thoracic endovascular aortic repair for chronic type B dissection with associated aneurysm is safe and effective at midterm follow-up. Aneurysm sac/false lumen pulse pressure measurements demonstrate a significant reduction in false lumen endotension, thus ruling out clinically significant persistent retrograde false lumen perfusion and provide proof of concept for a thoracic endovascular aortic repair-based approach. Longer-term follow-up is needed to determine the durability of thoracic endovascular aortic repair for this aortic pathology.

Laser Doppler flowmetry assessment of peristernal perfusion after cardiac surgery: beneficial effect of negative pressure therapy.

Negative pressure therapy has been successfully applied to clean, closed incisions in patients at high-risk for wound complications. Using laser Doppler flowmetry, we evaluated peristernal perfusion after cardiac surgery via median sternotomy, assessing the influence of mammary artery harvesting and the impact of negative pressure therapy. Twenty adult patients underwent median sternotomy for cardiac surgery followed by routine closure. Negative pressure was applied at 125 mm Hg for 4 days postoperatively in patients with increased risk for wound complications (n = 10, negative pressure group); standard dressings were applied to control incisions postoperatively (n = 10). Presternal perfusion was determined at baseline and daily for 4 days postoperatively using laser Doppler flowmetry. Results within and between groups were compared with analysis of variance. No wound complications were encountered in either group. Perfusion increased among the patients who underwent negative pressure therapy and decreased among the controls (P = 0.004). Mammary artery harvesting reduced peristernal perfusion by 25.7% in the controls, but negative pressure increased perfusion by 100% after mammary harvesting (P = 0.04). Negative pressure therapy increased perfusion relative to controls and compensated for reduced perfusion rendered by mammary artery harvesting, providing additional support for 'well wound therapy' in high-risk patients.

Influence of patient age on procedural selection in mitral valve surgery.

BACKGROUND: Previous studies suggest that mitral valve replacement is comparable to repair in the elderly, and a national trend exists toward tissue valves. However, few direct comparison data are available, and this study evaluated the effects of patient age on risk-adjusted survival after mitral procedures. METHODS: From 1986 to 2006, 2,064 patients underwent isolated primary mitral operations (±CABG). Maximal follow-up was 20 years with a median of 5 years. Valve disease etiology was the following: degenerative, 864; ischemic, 450; rheumatic, 416; endocarditis, 98; and "other," 236. Overall, 58% had repair and 39% had concomitant coronary artery bypass grafting. Survival differences were evaluated with a Cox proportional hazards model that included baseline characteristics, valve disease etiology, and choice of repair versus replacement with tissue or mechanical valves. RESULTS: Baseline risk profiles generally were better for mechanical valves, and age was the most significant multivariable predictor of late mortality [hazard ratio = 1.4 per 10-year increment, Wald χ(2) = 32.7, p < 0.0001]. As compared with repair, risk-adjusted survival was inferior with either tissue valves [1.8, 27.6, <0.0001] or mechanical valves [1.3, 8.1, 0.0044], and no treatment interaction was observed with age (p = 0.18). At no patient age did tissue valves achieve equivalent survival to either repair or mechanical valves. CONCLUSIONS: Mitral repair is associated with better survival than valve replacement across the spectrum of patient age. If replacement is required, mechanical valves achieve better outcomes, even in the elderly. These data suggest that tissue valves should be reserved only for patients with absolute contraindications to anticoagulation who are not amenable to repair.

Does negative pressure wound therapy have a role in preventing poststernotomy wound complications?

BACKGROUND: Sternal wound infection (SWI) remains a devastating complication after cardiac surgery, decreasing long-term and short-term survival. In treating documented SWI, negative pressure wound therapy (NPWT) reduces wound edema and time to definitive closure and improves peristernal blood flow after internal mammary artery (IMA) harvesting. The authors evaluated NPWT as a form of "well wound" therapy in patients at substantial risk for SWI based on existing risk stratification models. METHODS: Records of 57 adult cardiac surgery patients (September 2006 to April 2008) were reviewed. After preoperative risk assessment, NPWT was instituted on the clean, closed sternotomy immediately after surgery and continued 4 days postoperatively. Adverse postoperative events, including SWI, need for readmission, and other complications, were documented. RESULTS: Mean age was 60.4 +/- 10 years, and 89.5% were male; 77.2% were obese (mean body mass index 35.3 +/- 6.7), 54.4% were diabetic, and 29 (50.9%) were both obese and diabetic. Coronary artery bypass (CAB) with single IMA was performed in 50.9% of the patients followed in frequency by combined CAB/valve, non-CAB surgery, and CAB with bilateral IMA. Estimated risk for SWI was 6.1 +/- 4%. All patients tolerated NPWT to completion. Thirty-day and in-hospital mortality was 1.8% and unrelated to DSWI. No treatment of SWI was required. CONCLUSIONS: In this high-risk cohort, 3 postoperative SWI cases were anticipated but may have been mitigated by NPWT. This is an easily applied and well-tolerated therapy and may stimulate more effective wound healing. Among patients with increased SWI risk, strong consideration should be given to NPWT as a form of "well wound" therapy.

"Real world" thoracic endografting: results with the Gore TAG device 2 years after U.S. FDA approval.

BACKGROUND: The Gore TAG thoracic endoprosthesis (W. L. Gore and Associates, Flagstaff, AZ) was approved by the U.S. Food and Drug Administration (FDA) for the treatment of thoracic aortic aneurysms on March 23, 2005, and remains the only FDA approved thoracic device to date. We present our experience with the TAG device for the 2 years post-approval to better characterize "real world" use and results outside the clinical trial setting. METHODS: Between March 23, 2005, and March 23, 2007, n = 91 thoracic endograft procedures were performed at our institution. Of these, n = 83 (91%) utilized the TAG device and form the basis of this report. Indications for endovascular repair were: fusiform or saccular aneurysm (n = 43; 52%), acute or chronic dissection (n = 30; 36%), acute or chronic traumatic transection (n = 7; 8%), and false aneurysm after prior aortic surgery (n = 3; 4%). A "hybrid" approach involving carotid-carotid bypass (n = 2), stage I elephant trunk procedure (n = 3), aortic arch debranching (n = 7), or complete visceral debranching (n = 5) was required in 20% of patients to create an adequate landing zone. RESULTS: Primary technical success rate was 98.8% (n = 82/83). Thirty-day rates of mortality and permanent stroke were both 3.6% (n = 3 each). Permanent paraparesis/paraplegia rate was 2.4% (n = 2). The 30-day rate of vascular or device-related complications requiring additional endovascular or open procedures was 7.2% (n = 6). During a mean duration of follow-up of 14 +/- 8 months (range 0-28), there was one late death from aneurysm rupture (1.2%) and one late conversion to open repair (1.2%). CONCLUSIONS: "Real world" utilization of the TAG device includes high rates of off-label use (nearly 50%) and "hybrid" techniques (20%) for the treatment of multiple pathologic entities of the thoracic and thoracoabdominal aorta. Regardless, short to mid-term results appear promising. Longer follow-up is needed to determine the durability of this approach.

Short-term and intermediate-term outcomes of aortic root replacement with St. Jude mechanical conduits and aortic allografts.

BACKGROUND: Few studies have directly evaluated outcomes in patients undergoing aortic root replacement with St. Jude mechanical conduits or aortic allografts (ALLO), yet both approaches have been advocated. The purpose of this study was to provide a detailed description of outcomes in a large series of aortic root replacements performed with either St. Jude mechanical conduits or aortic allografts. METHODS: A retrospective analysis was performed on 172 consecutive adult patients undergoing aortic root replacement with either St. Jude mechanical conduits (n = 73) or aortic allografts (n = 99) from January 1990 to December 2002. Maximal follow-up was 15 years, and median follow-up was 5 years. RESULTS: Both groups were similar with regard to median age, preoperative ejection fraction, and New York Heart Association class. The aortic allograft patient group had a higher proportion (p < 0.05) of women (43% versus 18%), prior sternotomies (52% versus 26%), preoperative renal failure (9% versus 1%), and cerebrovascular disease (16% versus 4%). Operative indications for the aortic allograft group were more frequently endocarditis (29% versus 3%; p < 0.0001) and prosthetic valve dysfunction (13% versus 1%; p < 0.01), and less frequently annuloaortic ectasia (34% versus 60%; p < 0.001) or aortic dissection (3% versus 26%; p < 0.0001). Concomitant coronary artery bypass grafting or other valve surgery was performed in 30% of patients in both groups. Incidence of early postoperative complications, including bleeding, stroke, renal failure, and respiratory failure, was similar in both groups. Thirty-day mortality was 5.5% in the St. Jude mechanical conduit group and 8.1% in the aortic allograft group (p = 0.4). Unadjusted actuarial survival at 1, 5, and 10 years was 90%, 81%, 67%, and 86%, 70%, 67%, for the St. Jude mechanical conduit and aortic allograft groups, respectively (p = 0.09). Event-free survival at 1 and 5 years was similar for both groups (p = 0.4). By multivariate analysis, New York Heart Association class III or IV, emergently performed aortic root replacement, and postoperative respiratory failure, but not valve conduit type (p = 0.3), were independent predictors of mortality. CONCLUSIONS: Aortic root replacement can be safely performed with either allograft or mechanical conduits, even in the setting of acute dissection, redo sternotomy, or endocarditis.

Reimplantation technique (David operation) for multiple sinus of valsalva aneurysms.

Sinus of Valsalva aneurysms are relatively uncommon, and surgical repair is indicated at the time of diagnosis whether or not symptoms are present. This generally entails closure using a patch technique because usually only one sinus is involved. We report here the successful treatment of multiple sinus of Valsalva aneurysms using a David reimplantation valve-sparing root replacement.

Pathologic nodal status predicts disease-free survival after neoadjuvant chemoradiation for gastroesophageal junction carcinoma.

BACKGROUND: The incidence of carcinoma of the gastroesophageal junction (GEJ) is rapidly increasing, and the prognosis remains poor. We examined outcomes in patients who received neoadjuvant chemoradiation for GEJ tumors to identify factors that predict disease-free (DFS) and overall (OS) survival. METHODS: A retrospective analysis was performed of 101 consecutive patients who received chemoradiation and surgery for GEJ carcinoma between 1992 and 2001. RESULTS: The median DFS and OS of all patients were 16 and 25 months, respectively. Twenty-eight patients with a complete histological response (T0N0) experienced greater DFS compared with all others (P = .02). Node-negative patients, regardless of T stage, experienced improved median DFS (24 months) compared with N1 patients (9 months; P = .01). Preoperative stage, age, tumor location, or Barrett's esophagus did not independently predict OS by univariate analysis. Multivariate analysis demonstrated that only posttreatment nodal status (P = .03)-not the degree of primary tumor response-predicted DFS. CONCLUSIONS: The nodal status of patients with GEJ tumors after neoadjuvant therapy is predictive of DFS after resection. The poor outcome in node-positive patients supports postneoadjuvant therapy nodal staging, because surgical aggressiveness should be tempered by the realization that cure is unlikely and median survival is short.

Low morbidity and mortality for bronchoplastic procedures with and without induction therapy.

BACKGROUND: The safety of bronchoplastic procedures after induction chemoradiotherapy is uncertain. This study examines short- and long-term outcomes after bronchoplastic procedures with and without induction therapy. METHODS: Between January 1997 and September 2004, more than 1,300 anatomic pulmonary resections for cancer were performed at a single institution. Of these, 73 patients required either sleeve lobectomy (57) or bronchoplasty (16), and were retrospectively analyzed. Nineteen patients (26%) received induction therapy; 15 received chemotherapy and radiation therapy and 4 received chemotherapy alone. Fifty-four patients underwent the bronchoplastic procedure without induction therapy. Mortality and early and late morbidity were analyzed. RESULTS: Mean follow-up was 25 months. Histology was nonsmall cell cancer in 62 (85%), carcinoid in 8 (11%), and renal cell cancer, schwannoma, and mucoepidermoid cancer in 1 patient each. There were 2 (2.7%) 30-day deaths, both in the group not receiving induction therapy. Of the surviving 71 patients, 70 had functional reconstructions at last follow-up. The overall 30-day complication rate was 30% (19 of 54) in patients not receiving induction therapy (no bronchopleural fistulas) and 42% (8 of 19) occurring in those receiving induction therapy (1 bronchopleural fistula). The long-term complication rate was 20% (11 of 54) among patients not receiving induction therapy and 5% (1 of 19) among those receiving induction therapy (completion pneumonectomy). There were no bronchovascular complications. Interventional bronchoscopy was required in 7 patients not receiving induction therapy, and was required in none of the patients receiving induction therapy. CONCLUSIONS: Anatomic pulmonary resections utilizing bronchoplastic techniques can be performed with low morbidity and mortality rates even after induction therapy.

A man with saphenous vein graft aneurysms after bypass surgery.

Saphenous vein graft (SVG) aneurysms are a rare complication of coronary artery bypass graft surgery. Patients in whom these aneurysms form a fistula with either a cardiac chamber or mediastinal vessel are even more uncommon and present a difficult diagnostic and therapeutic challenge. We present a patient with SVG aneurysms and a fistula to the left atrium.

Evaluation of vacuum-assisted closure in the treatment of poststernotomy mediastinitis.

OBJECTIVE: Poststernotomy mediastinitis, although infrequent, is a potentially life-threatening complication of cardiac surgery that continues to have a significant morbidity and mortality despite aggressive therapy. Vacuum-assisted closure uses controlled suction to provide evacuation of wound fluid, decrease bacterial colonization, stimulate granulation tissue, and reduce the need for dressing changes. METHODS: One hundred two patients from Duke University Hospital, The Durham Veterans Administration Hospital, and referring institutions underwent vacuum-assisted closure treatment. There were 63 men and 39 women, with a mean age of 67. The infection was noticed between postoperative days 8 and 34, at which time the wounds were opened and debrided. RESULTS: Ninety-six of the 102 patients received vacuum-assisted therapy while the remaining 6 underwent daily multiple dressing changes without vacuum-assisted therapy. Fifty-three of the 96 patients required only sternal debridement, followed by wound vacuum therapy and closure by secondary intention, while the remaining 43 had an additional procedure. Of these, 33 patients underwent omental transposition and 10 patients had a pectoralis flap. The length of stay for all patients was 27 +/- 12 days. This was related in part to intravenous antibiotics. Hospital mortality for all patients was 3.7% (4 patients). Two of these patients underwent vascular flap and succumbed to multisystemic organ failure, while the other 2 received only wound vacuum therapy following debridement and succumbed to overwhelming sepsis. CONCLUSION: Vacuum-assisted drainage is an effective therapy for mediastinitis following debridement or before placement of a vascularized tissue flap.

Control of the pleural space after pneumonectomy.

The authors believe that most patients who undergo pneumonectomy do not require drainage of the postpneumonectomy space. Needle or catheter aspiration is simple and usually adequate. In cases in which significant bleeding, rapid pleural fluid accumulation, or contamination is expected, however, drainage of the space is recommended. If drainage is used, the tube probably should be connected to a balanced drainage system to ensure proper physiologic positioning of the mediastinum during the critical immediate postoperative period.

Mitral surgery after prior cardiac operation: port-access versus sternotomy or thoracotomy.

BACKGROUND: In reoperation for mitral valve disease, minimally invasive Port-Access (PORT) is a new alternative to standard median sternotomy (STER) or right thoracotomy (THOR); yet, the results of PORT in this setting have not been defined. The aim of this study was to evaluate the results of minimally invasive thoracotomy in reoperation for mitral valve disease. METHODS: Retrospective results are reported for three consecutive series of patients undergoing reoperation for mitral disease using either PORT (n = 60, 1996 to 2001), THOR (n = 37, 1985 to 1997), or STER (n = 155, 1985 to 1997). RESULTS: Red cell transfusion was 3 +/- 4, 14 +/- 13, and 12 +/- 12 units for PORT, THOR, and STER, respectively. Chest tube output was 352 +/- 361, 2048 +/- 3166, and 1683 +/- 3939 mL, respectively. Cardiopulmonary bypass times for these groups were 208 +/- 76 vs. 158 +/- 56 vs. 157 +/- 53 minutes. Thirty-day mortality was 0/60 (0%), 8/37 (22%), and 21/155 (14%), respectively. CONCLUSIONS: This early clinical experience suggests that PORT is an acceptable alternative to THOR or STERN in reoperation for mitral valve disease, with potential advantages of avoiding redo sternotomy and reducing the surgical incision. However, these benefits may come at the expense of longer cardiopulmonary bypass times.