Malakh Shrestha

Hypothermic circulatory arrest with selective antegrade cerebral perfusion in ascending aortic and aortic arch surgery: A risk factor analysis for adverse outcome in 501 patients

OBJECTIVE This study was undertaken to identify preoperative and intraoperative risk factors influencing outcome after operations requiring hypothermic circulatory arrest with selective antegrade cerebral perfusion in a single center. METHODS Between November 1999 and March 2006, a total of 501 consecutive patients (median age 64 years, range 20-86 years, 320 male) underwent aortic arch surgery with moderate hypothermic circulatory arrest (25 degrees C +/- 2 degrees C) and additional selective antegrade cerebral perfusion (14 degrees C) at our institution for various indications (256 aneurysms, 153 acute and 23 chronic type A aortic dissections, 66 other). Of these, 181 were emergency operations. Statistical analysis was carried out to determine risk factors for 30-day mortality as well as for temporary and permanent neurologic dysfunction. RESULTS Overall mortality was 11.6%. Permanent neurologic dysfunction occurred in 48 patients (9.6%); temporary neurologic dysfunction was detected in 67 patients (13.4%). Multivariate analysis revealed age (P = .001, odds ratio 1.08), reoperation (P = .006, odds ratio 3.58), femoral arterial cannulation (P = .004, odds ratio 2.87), and cardiopulmonary bypass duration (P < .001, odds ratio 1.009) as risk factors for mortality. Permanent neurologic dysfunction was associated with preoperative renal insufficiency (P = .029, odds ratio 2.79) and operation time (P < .001, odds ratio 1.005), whereas temporary neurologic dysfunction occurred in patients with coronary artery disease (P = .04, odds ratio 2.29), emergency surgery (P = .001, odds ratio 4.09), and increasing hypothermic circulatory arrest duration (P = .01, odds ratio 1.015). CONCLUSION Moderate hypothermic circulatory arrest in combination with cold selective antegrade cerebral perfusion is an adequate tool for neuroprotection during aortic surgery. Nevertheless, the safety of this technique is limited for patients with long intraoperative durations, advanced age, and multiple comorbidities. This technique, which avoids profound core temperatures, has become an alternative to simple deep hypothermic circulatory arrest.

Ascending aortic cannulation in acute aortic dissection type A: the Hannover experience

OBJECTIVE The incidence of embolic events and of cerebral malperfusion in aortic dissection type A (AADA) must be viewed in the context of the existence of a number of possible cannulation techniques. Since femoral cannulation is thought to be associated with a higher risk of perfusion of the false lumen and retrograde embolization, techniques establishing antegrade flow may provide a better option. We describe herein our experience with ascending aortic cannulation in this special patient population. METHODS Between November 1999 and February 2006, 122 patients underwent operation for AADA with arterial access via the dissected ascending aorta. The aorta was cannulated at the site of the minimal distances of the dissected layers. Double purse-string sutures were used to support the cannula. Pressure monitoring in both radial arteries as well as bilateral cerebral oxygen saturation measurement helped to identify malperfusion after establishment of cardiopulmonary bypass. Aortic arch as well as aortic root surgery was performed, as dictated by the pathology. Selective antegrade cerebral perfusion and moderate hypothermia were used for brain and body protection. RESULTS Malperfusion occurred in three patients (2.5%). Hospital mortality was 15% for the entire cohort (18 patients). Permanent neurological dysfunction was detected in 15 patients (12%), whereas temporary neurological dysfunction occurred in 21 (17%). Total arch replacement was performed in 31 patients (25%). CONCLUSION Direct cannulation of the ascending aorta is an easy and safe method in patients with AADA. This technique, which also avoids retrograde flow in the downstream aorta, is an alternative to time-consuming axillary artery access.

Current status and recommendations for use of the frozen elephant trunk technique: a position paper by the Vascular Domain of EACTS

The implementation of new surgical techniques offers chances but carries risks. Usually, several years pass before a critical appraisal and a balanced opinion of a new treatment method are available and rely on the evidence from the literature and experts opinion. The frozen elephant trunk (FET) technique has been increasingly used to treat complex pathologies of the aortic arch and the descending aorta, but there still is an ongoing discussion within the surgical community about the optimal indications. This paper represents a common effort of the Vascular Domain of EACTS together with several surgeons with particular expertise in aortic surgery, and summarizes the current knowledge and the state of the art about the FET technique. The majority of the information about the FET technique has been extracted from 97 focused publications already available in the PubMed database (cohort studies, case reports, reviews, small series, meta-analyses and best evidence topics) published in English.

Long-term results after aortic valve-sparing operation (David I)

OBJECTIVE Aortic valve-sparing David procedure has gained broad acceptance. However, few long-term results have been published. We present our results. METHODS More than 450 David procedures have been performed in our institution so far. Of these, 126 patients were operated between July 1993 and December 2000. Median age was 57 (8-83) years and 46 (36.5%) were female. As many as 26 (20.6%) had Marfan syndrome, 21 (16.7%) had acute aortic dissection type A (AADA) and 67 (53.2%) had additional procedures. RESULTS There were six (4.8%) deaths in 30 post-operative period (POD), four of whom had AADA. In the follow-up, there were 32 (25.4%) late deaths, 11 (34.4%) of these were caused by cardiac or underlying disease or op-related. As many as 15 (11.9%) patients were re-operated; six (40%) were Marfan patients and two (13.3%) had early endocarditis. Follow-up echocardiography of 76 (60.3%) event-free patients showed valve insufficiency (AI)≤AI I° in 68 (89.5%) and grade II in 7 (9.2%) patients. Leaflet degeneration due to proposed leaflet contact with the straight Dacron graft was not observed. A total of 36 (47.4%) patients were in New York Heart Association (NYHA) class I, 33 (43.4%) in NYHA II, and five (6.6%) were in class III. During the entire follow-up of 790 patient-years, there was no stroke or major bleeding. Survival at 1, 5 and 10 years was 93%, 85% and 70%, respectively. Freedom from valve replacement at 1, 5 and 10 years was 96%, 91% and 87%, respectively. CONCLUSIONS Regardless of the underlying pathology, valve-sparing David I procedure has acceptable long-term results. Valve-related complications such as stroke or major bleeding is exceedingly low.

Sutureless aortic valve replacement: a systematic review and meta-analysis.

BACKGROUND Sutureless aortic valve replacement (SU-AVR) has emerged as an innovative alternative for treatment of aortic stenosis. By avoiding the placement of sutures, this approach aims to reduce cross-clamp and cardiopulmonary bypass (CPB) duration and thereby improve surgical outcomes and facilitate a minimally invasive approach suitable for higher risk patients. The present systematic review and meta-analysis aims to assess the safety and efficacy of SU-AVR approach in the current literature. METHODS Electronic searches were performed using six databases from their inception to January 2014. Relevant studies utilizing sutureless valves for aortic valve implantation were identified. Data were extracted and analyzed according to predefined clinical endpoints. RESULTS Twelve studies were identified for inclusion of qualitative and quantitative analyses, all of which were observational reports. The minimally invasive approach was used in 40.4% of included patients, while 22.8% underwent concomitant coronary bypass surgery. Pooled cross-clamp and CPB duration for isolated AVR was 56.7 and 46.5 minutes, respectively. Pooled 30-day and 1-year mortality rates were 2.1% and 4.9%, respectively, while the incidences of strokes (1.5%), valve degenerations (0.4%) and paravalvular leaks (PVL) (3.0%) were acceptable. CONCLUSIONS The evaluation of current observational evidence suggests that sutureless aortic valve implantation is a safe procedure associated with shorter cross-clamp and CPB duration, and comparable complication rates to the conventional approach in the short-term.

Aortic valve replacement in geriatric patients with small aortic roots: are sutureless valves the future?

OBJECTIVES Aortic valve replacement (AVR) in geriatric patients (>75 years) with small aortic roots is a challenge. Patient-prosthesis mismatch and the long cross-clamp time necessary for stentless valves or root enlargement are matters of concern. We compared the results of AVR with sutureless valves (Sorin Perceval), against those with conventional biological valves. METHODS Between April 2007 and December 2012, 120 isolated AVRs were performed in patients with a small annulus (<22 mm) at our centre. In 70 patients (68 females, age 77.4 ± 5.5 years), conventional valves (C group) and in 50 patients (47 females, age 79.8 ± 4.5 years), sutureless valves (P group) were implanted. The Logistic EuroSCORE of the C group was 16.7 ± 10.4 and that of the P group 20.4 ± 10.7, (P = 0.054). Minimal-access surgery was performed in 4.3% (3/70) patients in the C group and 72% (36/50) patients in the P group. RESULTS The cardiopulmonary bypass (CPB) and cross-clamp times of the C group were 75.3 ± 23 and 50.3 ± 14.2 min vs 58.7 ± 20.9 and 30.1 ± 9 min in the P group, (P < 0.001). In the C group, two annulus enlargements were performed. Thirty-day mortality was 4.3% (n = 3) in the C group and 0 in the P group, (n.s.). At follow-up (up to 5 years), mortalities were 17.4% (n = 12) in the C group and 14% (n = 7) in the P group, (n.s.). CONCLUSIONS This study highlights the advantages of sutureless valves for geriatric patients with small aortic roots reflected by shorter cross-clamp and CPB times, even though most of these patients were operated on via a minimally invasive access. Moreover, due to the absence of a sewing ring, these valves are also almost stentless, with greater effective orifice area (EOA) for any given size. This may potentially result in better haemodynamics even without the root enlargement. This is of advantage, as several studies have shown that aortic root enlargement can significantly increase the risks of AVR. Moreover, as seen in this series, these valves may also enable a broader application of minimally invasive AVR.

European multicentre experience with the sutureless Perceval valve: clinical and haemodynamic outcomes up to 5 years in over 700 patients†.

OBJECTIVES This report summarizes the 5-year clinical and haemodynamic data from three prospective, European multicentre trials with the Perceval sutureless aortic valve. METHODS From April 2007 to August 2012, 731 consecutive patients (mean age: 78.5 years; 68.1% females; mean logistic EuroSCORE 10.9%) underwent AVR with the Perceval valve in 25 European centres. Isolated AVR was performed in 498 (68.1%) patients. A minimally invasive approach was performed in 189 (25.9%) cases. The cumulative follow-up was 729 patients-years. RESULTS In isolated AVR, mean cross-clamp and cardiopulmonary bypass times were 30.8 and 50.8 min in full sternotomy, and 37.6 and 64.4 min in the minimally invasive approach, respectively. Early cardiac-related deaths occurred in 1.9%. Overall survival rates at 1 and 5 years were 92.1 and 74.7%, respectively. Major paravalvular leak occurred in 1.4% and 1% at early and late follow-up, respectively. Significant improvement in clinical status was observed postoperatively in the majority of patients. Mean and peak gradients decreased from 42.9 and 74.0 mmHg preoperatively, to 7.8 and 16 mmHg at the 3-year follow-up. LV mass decreased from 254.5 to 177.4 g at 3 years. CONCLUSIONS This European multicentre experience, with the largest cohort of patients with sutureless valves to date, shows excellent clinical and haemodynamic results that remain stable even up to the 5-year follow-up. Even in this elderly patient cohort with 40% octogenarians, both early and late mortality rates were very low. There were no valve migrations, structural valve degeneration or valve thrombosis in the follow-up. The sutureless technique is a promising alternative to biological aortic valve replacement.

A Staged Approach towards Interventional Aortic Valve Implantation with a Sutureless Valve: Initial Human Implants

OBJECTIVE Percutaneous implantable aortic valves may become an alternative to conventional approaches. The purpose of this study was to assess a new sutureless aortic valve (Perceval Sorin). As a first step, an open approach using cardiopulmonary bypass (CPB) was chosen to evaluate the feasibility of implantation. METHODS Between April and September 2007, 16 high-risk patients (13 females, aged 81 [76 - 88]) were operated on via a median sternotomy, using CPB and cardioplegia (Euro Score 17 [8 - 73]). All patients had significant aortic valve disease and seven of these patients had concomitant coronary artery disease. This pilot project was initiated with prior approval of the Institutional Review Board. All patients gave informed consent. RESULTS One patient died during hospital stay for unknown reasons. Autopsy revealed no valve related pathologies. CPB time was 60 min (41 - 130), cross-clamping time was 36 (22 - 79) min. Intraoperative as well as postoperative echocardiography revealed neither aortic insufficiency nor paravalvular leakage in any of the patients. CONCLUSIONS The new approach as described here is a technically simple alternative to conventional aortic valve replacement in high-risk patients and offers the potential of less invasive approaches. It appears especially useful in patients with severe calcification of the aortic root. CPB and cross-clamping times were markedly reduced compared with patients who underwent conventional operations.

Impact of clinical factors and surgical techniques on early outcome of patients treated with frozen elephant trunk technique by using EVITA open stent-graft: results of a multicentre study

OBJECTIVES The treatment of patients with extensive thoracic aortic disease involving the arch and descending aorta is often performed, using the frozen elephant trunk (FET) technique. We retrospectively analysed early outcomes with this technique, using a prospective database. METHODS A total of 509 patients (mean age: 61 ± 11 years) were registered between January 2005 and January 2014 in a multicentre database after FET surgery. Acute or chronic aortic dissection (AD) was the indication for surgery in 350 (68.8%) patients and degenerative or atherosclerotic aneurysm (DA) accounted for 159 (31.2%) patients. A logistic regression model was created to identify independent predictors of in-hospital mortality and neurological complications. RESULTS The average in-hospital mortality was 15.9% (n = 81) with 17.1% for AD patients and 13.2% for DA patients (P = 0.2). Independent predictors of in-hospital mortality were haemodynamic instability [odds ratio (OR): 2.7, P = 0.005], peripheral vascular disease (OR: 2.6, P = 0.002), diabetes (OR: 2.1, P = 0.05) and selective cerebral perfusion time >60 min (OR: 2.2, P = 0.005). Patients under 60 years of age and the use of guide wire during FET implantation were protective for early survival. Stroke occurred in 7.7% (n = 39) of patients. Paraplegia or paraparesis occurred in 7.5% (n = 38) of patients. A distal landing zone lower than T10 was an independent predictor for spinal cord injury (OR: 2.3, P = 0.03). CONCLUSIONS Techniques for faster arch replacement and controlled FET placement should be considered in order to reduce the early mortality and neurological complications after FET surgery. For distal aortic lesions, a two-staged approach is suggested, rather than the FET landing lower than T10.

Isolated surgical aortic valve replacement after previous coronary artery bypass grafting with patent grafts: is this old-fashioned technique obsolete?

AIM High-risk patients are currently being evaluated for various catheter-based aortic valve replacement (AVR) techniques. To identify an individual patients risk, scores such as the EuroSCORE or STS risk calculator (RC) are used. The aim of the present study was to evaluate the surgical results in patients who underwent isolated AVR via a median re-sternotomy after prior CABG. PATIENTS AND METHODS Between 01/96 and 01/08, 349 patients underwent AVR as a redo procedure. One hundred and thirty patients had undergone previous CABG; in 39 patients (29 male, median age 75 (60-84)) preoperative coronary angiography revealed open grafts with no need for additional revascularization (30 had LIMA grafts). These patients underwent isolated AVR. Operative mortality was calculated using the standard and logistic EuroSCORE, and the STS RC. RESULTS Operative (30-day mortality) was 5% (2 patients). Mean calculated predicted mortality rates for the cohort were: 12+/-3% for the standard, and 32+/-21% for the logistic EuroSCORE, and 10+/-4% according to the STS RC. Receiver operated characteristics (ROC) analysis revealed 100% specificity for standard EuroSCOREs up to 12.5%, logistic EuroSCOREs up to 39.7% and up to 17.45% for STS RC, with a sensitivity of 69.5%, 75% and 97.2%, respectively. The STS RC showed significant better prediction of mortality than the EuroSCOREs (p=0.006). CONCLUSIONS Conventional AVR as a redo procedure after CABG with patent grafts can be performed with excellent results and lower mortality than estimated. Results of newer catheter-based AVR approaches should not to be compared with artificial scores to justify high morbidity rates.