Minimally invasive approaches to aortic valve surgery: Brigham experience

Aortic valve surgery is a proven and effective therapy for severe aortic stenosis and insufficiency. Conventional aortic valve surgery is performed with a full sternotomy, cardiopulmonary bypass, and replacement of the diseased aortic valve. Unlike minimally invasive (or "off-pump") coronary artery bypass, minimally invasive aortic valve surgery still requires cardiopulmonary bypass but refers primarily to smaller incisions and access. Minimally invasive approaches to aortic valve surgery have evolved over the past decade and have become the standard in institutions that perform large-volume minimally invasive cardiac surgery. The upper hemisternotomy has become our standard approach to isolated aortic valve surgery. It is a safe and effective technique with a similar morbidity and mortality to conventional aortic valve surgery. Patients derive clear benefits from this minimally invasive approach including less pain, shorter length of hospital stay, and faster return to preoperative function levels.     

Minimally invasive valve surgery

BACKGROUND: Cardiac surgery has been the last area of clinical surgery to adopt and embrace minimally invasive surgical techniques. Since the onset of arterial embolectomy in 1965, arthroscopic knee surgery performed in 1975 and laparoscopic cholecystectomy in 1985, huge advances in videoscopic, thorascopic and small incision surgery has taken place in all specialties which now allow change in the traditional approaches to cardiac valve surgery. In 1996, the Brigham and Women's Hospital, along with other units, began minimally invasive cardiac valve surgery for patients who had isolated valve pathology without coronary disease. Our experience now totals 689 patients, including 353 minimally invasive mitral valve repair/replacements and 336 minimally invasive aortic valve replacements, including root replacement and reoperations. METHODS: This new operative approach involves smaller incisions, the mandatory use of transesophageal echocardiogram for the monitoring of operation quality and air removal, newer perfusion techniques and some modifications in the standard valve repair/replacement techniques. With this blending of TEE, better perfusion techniques and new exposure, the safety and quality of valve operations by these techniques have been excellent. RESULTS AND CONCLUSION: The operative mortality is equal to (AVR) or less than (MVP) conventional open sternotomy cases and there is a shorter length of stay in the ICU and post-ICU, leading to a lower cost than conventional procedures. There are also less blood transfusions, atrial fibrillation and posthospital rehabilitation requirements, and patients have indicated that there is a faster return to normality over the conventional operative approaches. This brief report summarizes our experience from July, 1996 to January 2001.     

微创小切口心脏瓣膜手术134例

目的总结经微创小切口行心脏瓣膜手术的临床经验,探讨手术径路、方法、效果以及可能的危险因素。方法采用微创小切口行心脏瓣膜手术134例,其中经胸骨旁切口行主动脉瓣置换术5例,二尖瓣置换术2例;经右胸前外侧切口行二尖瓣手术46例,单纯三尖瓣手术15例;经胸骨上段小切口(反Z字形)行主动脉瓣置换术11例;经胸骨下段劈开加横断右半胸骨(倒L形)切口行二尖瓣手术55例。结果术后早期死亡3例,其中2例死于低心排血量综合征和右心功能不全,1例死于急性肝、肾功能衰竭。随访114例,随访时间2个月~7年,术后6个月患者的心功能均有不同程度的改善,切口疤痕隐蔽,复查心脏彩色超声心动图显示心瓣膜功能良好。结论微创小切口行心脏瓣膜手术可行,避免了完全劈开胸骨,维持胸廓的完整性,减少损伤,相对美观,有利于患者术后的恢复。     

Hemisternotomy approach for aortic and mitral valve surgery

After exploring several less invasive approaches for cardiac valve surgery, we have concluded that the partial upper sternotomy is the incision of choice for minimally invasive aortic and mitral valve surgery. From March 1997 to January 1999, 827 patients had cardiac valve surgery using this approach; 462 had mitral valve procedures and 365 had aortic valve procedures. Of those having mitral valve surgery, 87% had mitral valve repair. Aortic valve surgery included replacement with stented bioprostheses (38%), allografts (29%), and mechanical prostheses (10%); in addition, 23% had aortic valve repair. Operative mortality was 0.8%. Conversion to full sternotomy was necessary in 2.4%. Blood use was low with 80% of patients receiving no blood transfusions. We conclude that all primary mitral and aortic procedures can be accomplished safely via partial upper sternotomy.     

Towards trends in minimal invasive cardiac surgery

While various minimally invasive techniques have been established in many other surgical specialties during the last decades, cardiac surgery has been one of the last domains to adopt the principles of minimally invasive techniques. This was mainly based on the reduced surgical exposure in highly complex cardiac operations and the missing technical requirements in the beginning of the modern cardiac era. Nowadays, technical conditions have continuously improved and have become routine also in cardiac surgery. Most of these novel minimal-invasive concepts have been developed in order to treat high-risk or inoperable patients by reducing operative trauma. Actually, since more high-risk and multimorbid patients were referred for surgery, these initial extraordinary procedures have been adopted into daily clinical routine. Currently, many promising innovations aim to reduce the operative trauma and perioperative morbidity, and furthermore, to increase patients' satisfaction and security. It is anticipated that in the future this current trend towards minimal invasiveness will increase further due to an increased demand, and therefore, such minimal-invasive procedures will become less complex and straightforward.     

Surgical, anesthetic, perfusion-related advances in minimal access surgery

As we enter the fifth decade in cardiac surgery, traditionally cardiac surgery has been performed using a median sternotomy with cardiopulmonary bypass providing great access to the heart and all the surrounding structures. During the last decade, there has been a paradigm shift in the methods by which surgery has been performed. The invasiveness of many procedures has been dramatically reduced, with significantly superior outcomes, as evidenced by improved survival, fewer complications, and quicker return to functional health and productive life. This resulted in significant interest and excitement in adopting less invasive techniques in cardiac surgery. Unfortunately, this was an unrealistic expectation due to the limitations that existed in cardiac surgical techniques and conventional endoscopic instruments, cardiac anesthesia, and cardiopulmonary bypass techniques. In this article, the advances in minimally invasive surgical, cardiac anesthesia, and cardiopulmonary bypass techniques in the evolution of minimal access cardiac surgery are summarized.     

Endoscopic aortic valve replacement

During the last 8 years, many different approaches for minimally invasive aortic valve surgery have emerged. We have developed a technique that enables total endoscopic aortic valve replacement with port access, via a small right lateral thoracotomy with only soft tissue retraction and minimally invasive aortic crossclamping. The operation is performed under video guidance, since no direct eye vision is possible. We believe this is the first such operation performed in cardiac surgery and that it mak es possible broadening of indications for nonsternotomy-video-directed surgery in the future.     

Minimally invasive cardiac valve surgery improves patient satisfaction while reducing costs of cardiac valve replacement and repair.

OBJECTIVE: This study compares the quality of valve replacement and repair performed through minimally invasive incisions as compared to the standard operation for aortic and mitral valve replacement. SUMMARY BACKGROUND DATA: With the advent of minimally invasive laparoscopic approaches to orthopedic surgery, urology, general surgery, and thoracic surgery, it now is apparent that standard cardiac valve operations can be performed through very small incisions with similar approaches. METHODS: Eighty-four patients underwent minimally invasive aortic (n = 41) and minimally invasive mitral valve repair and replacement (n = 43) between July 1996 and April 1997. Demographics, procedures, operative techniques, and postoperative morbidity and mortality were calculated, and a subset of the first 50 patients was compared to a 50-patient cohort who underwent the same operation through a conventional median sternotomy. Demographics, postoperative morbidity and mortality, patient satisfaction, and charges were compared. RESULTS: Of the 84 patients, there were 2 operative mortalities both in class IV aortic patients from multisystem organ failure. There was no operative mortality in the patients undergoing mitral valve replacement or repair. The operations were carried out with the same accuracy and attention to detail as with the conventional operation. There was minimal postoperative bleeding, cerebral vascular accidents, or other major morbidity. Groin cannulation complications primarily were related to atherosclerotic femoral arteries. A comparison of the minimally invasive to the conventional group, although operative time and ischemia time was higher in minimally invasive group, the requirement for erythrocytes was significantly less, patient satisfaction was significantly greater, and charges were approximately 20% less than those in the conventional group. CONCLUSIONS: Minimally invasive aortic and mitral valve surgery in patients without coronary disease can be done safely and accurately through small incisions. Patient satisfaction is up, return to normality is higher, and requirement for postrehabilitation services is less. In addition, the charges are approximately 20% less. These results serve as a paradigm for the future in terms of valve surgery in the managed care environment.     

Routine minimally invasive aortic valve procedures

BACKGROUND: Due to the lack of objective evidence supporting the advantages and early technical difficulties, minimally invasive aortic valve procedures were performed on a highly selective rather than routine basis. METHODS: From September 1997 to February 1999, one surgeon routinely used upper or transverse minimally invasive sternotomy to perform 46 consecutive cases of aortic valve procedures (M), whereas two other surgeons performed 40 aortic valve procedures through a conventional sternotomy (C). RESULTS: More time consuming and technically demanding surgeries were done in M. There was one death in each group. Aortic clamp time was longer in M (93+/-40 vs 59+/-24 min, P=0.001). There were no differences in operating time, pump time, intubation duration, bleeding and intensive care unit stay. The advantages of minimally invasive aortic valve operation included better postoperative ejection fraction (58+/-17 vs 51+/-10%, P=0.04), decreased pain score (3+/-2 vs 5+/-2, P=0.004), less transfusion (19 vs 55%, P=0.02), shorter duration of chest tube drainage, and cosmetically more acceptable surgical wound (6.8+/-2.2 vs 5.2+/-2.0, P=0.018). From our series, we could not find any negative effects of minimal access surgery. CONCLUSIONS: Our study demonstrated that aortic valve surgeries could be performed routinely by the minimally invasive approach with a high degree of effectiveness and safety.     

Coronary Surgery: off-pump and port access

Attempts to minimize the invasiveness of cardiac surgery have focused on decreasing access trauma and eliminating cardiopulmonary bypass. The initial procedures, minimally invasive direct coronary artery bypass (MIDCAB, limited access beating heart) and port access (limited access arrested heart), have become niche procedures. Off-pump coronary artery bypass (OPCAB, median sternotomy beating heart) presently accounts for approximately 15% of all coronary bypass operations performed in the United States. Morbidity and cost appear to be decreased with these procedures. Feasibility trials of endoscopic coronary bypass surgery using robotic devices are underway in many centers. It is anticipated that over the next 5 years the alternative approaches to conventional coronary artery bypass surgery will continue to grow as methods of coronary revascularization.     

Surgical management of minimally invasive aortic valve operations

Although there is still a role for conventional sternotomy for aortic valve replacement, minimally invasive techniques are increasing in popularity and may benefit the patient with shorter postoperative course, less morbidity, and decreased overall cost. Additionally, transcatheter procedures have recently shown promising results in high-risk patients. This article provides an overview of the development of minimally invasive aortic valve operations, including a brief history of minimally invasive approaches, surgical considerations during minimally invasive aortic valve replacement, and the technical approach to performing a hemisternotomy with aortic valve replacement. In addition, the authors review transcatheter techniques, including aortic valve replacement via a sheath placed in the apex of the left ventricle or through a sheath placed in the femoral vessels. Finally, the exciting results of the PARTNER trial and the effect of these results on the future of aortic valve surgery are discussed.     

Minimally invasive cardiac surgery: surgical techniques and anesthetic problems]

OBJECTIVE: To review current data on minimally invasive cardiac surgery. DATA SOURCES: Search through the Medline data base of French or English articles. DATA EXTRACTION: The articles were analysed to make a synthesis of the various techniques with their main indications and contra-indications. DATA SYNTHESIS: Minimally invasive cardiac surgery includes various surgical procedures. The usual techniques are described, their major benefits and drawbacks are discussed. The main goals of anaesthetic management are preservation of ventricular function and systemic perfusion, detection and treatment of myocardial ischaemia, prevention of hypothermia in case of coronary artery bypass grafting on the beating heart via sternotomy, intermittent selective ventilation of the collapsed lung using CPAP in case of limited thoracotomy. Expertise in transoesophageal echocardiography is essential for insertion and checking the accurate positioning of the various catheters of the endovascular CPB Heartport system (pulmonary vent, endosinus catheter, venous cannula, endoaortic clamp) allowing coronary artery bypass grafting and mitral valve surgery through limited thoracotomy and finally, detection of retained intracardiac air and assessment of complete clearing of cardiac cavities after mitral valve surgery through limited thoracotomy and aortic valve surgery via ministernotomy. Short-acting anaesthetic agents allow rapid recovery from anaesthesia, early extubation and discharge to the surgical ward within 24 h, whereas overall time spent in the operating room is often longer than with conventional cardiac surgery.     

Minimally invasive cardiac surgery for aortic valve disease

Recent surgical advances leading to good operative results have contributed to the trend to useminimally invasive approaches, even in cardiac surgery. Smaller incisions are clearly more cosmetically acceptable to patients. When using a minimally invasive approach, it is most important to maintain surgical quality without jeopardizing patients. A good operative visual field leads to good surgical results. In the parasternal approach, we use a retractor to harvest an internal thoracic artery in coronary artery bypass surgery. Retracting the sternum upward allows for a good surgical view and permits the use of an arch cannula rather than femoral cannulation. When reoperating for aortic valve repair, the j-sternotomy approach requires less adhesiolysis compared with the traditional full sternotomy. No special technique is necessary to perform aortic valve surgery using the j-sternotomy approach. However, meticulous attention must be paid to avoiding left ventricular air embolisms to prevent postoperative stroke or neurocognitive deficits, especially when utilizing a minimally invasive approach. Transesophageal echo is useful not only for monitoring cardiac function but also for monitoring the persence of air in the left ventricle and atrium. This paper compare as the degree of invasion of minimally invasive cardiac surgery and the traditional full sternotomy. No differences were found in the occurrence of systemic inflammatory response syndrome between patients undergoing minimally invasive cardiac surgery and the traditional technique. Therefore it is concluded that minimally invasive surgery for patients with aortic valve disease may become the standard approach in the near future.     

Minimally Invasive Approach for Redo Mitral Valve Surgery: A True Benefit for the Patient

ABSTRACT Objectives Redo mitral valve surgery via sternotomy is associated with a substantial morbidity and mortality. This study evaluated a minimally invasive technique for mitral valve redo procedures. Material and Methods: Out of a series of 394 patients undergoing mitral valve repair or replacement via a right minithoracotomy, 39 patients underwent redo mitral valve surgery (59 ± 13 years, 23 female). Previous cardiac surgeries included 17 patients with mitral valve repair, 6 patients with mitral valve replacement, 3 patients with aortic valve replacement, 2 patients with atrial septal defect closure, and 11 patients with coronary artery bypass grafting (CABG). In all cases, femoro-femoral cannulation was performed. The port access technique was applied in patients undergoing redo valve surgery. In patients with prior CABG, the operation was performed using deep hypothermia and ventricular fibrillation. Results: In all cases, sternotomy was avoided. The mitral valve was replaced in 20 patients and repaired in 19. Time of surgery and cross-clamp time were comparable with the overall series (168 ± 73 [redo] vs 168 ± 58 min and 52 ± 21 [redo] vs 58 ± 25 min). Mortality was 5.1%. One patient had transient hemiplegia due to the migration of the endoclamp. All other patients had uneventful outcomes and normal mitral valve function at 3-month's follow-up. Conclusion: Redo mitral valve surgery can be performed safely using a minimally invasive approach in patients with a previous sternotomy. The right lateral minithoracotomy offers excellent exposure. It minimizes the need for cardiac dissection, and thus, the risk for injury. Avoiding a resternotomy increases patient comfort of redo mitral valve surgery.     

Minimally invasive approach for redo mitral valve surgery: a true benefit for the patient

OBJECTIVES: Redo mitral valve surgery via sternotomy is associated with a substantial morbidity and mortality. This study evaluated a minimally invasive technique for mitral valve redo procedures. MATERIAL AND METHODS: Out of a series of 394 patients undergoing mitral valve repair or replacement via a right minithoracotomy, 39 patients underwent redo mitral valve surgery (59+/-13 years, 23 female). Previous cardiac surgeries included 17 patients with mitral valve repair, 6 patients with mitral valve replacement, 3 patients with aortic valve replacement, 2 patients with atrial septal defect closure, and 11 patients with coronary artery bypass grafting (CABG). In all cases, femoro-femoral cannulation was performed. The port access technique was applied in patients undergoing redo valve surgery. In patients with prior CABG, the operation was performed using deep hypothermia and ventricular fibrillation. RESULTS: In all cases, sternotomy was avoided. The mitral valve was replaced in 20 patients and repaired in 19. Time of surgery and cross-clamp time were comparable with the overall series (168+/-73 [redo] vs 168+/-58 min and 52+/-21 [redo] vs 58+/-25 min). Mortality was 5.1%. One patient had transient hemiplegia due to the migration of the endoclamp. All other patients had uneventful outcomes and normal mitral valve function at 3-month's follow-up. CONCLUSION: Redo mitral valve surgery can be performed safely using a minimally invasive approach in patients with a previous sternotomy. The right lateral minithoracotomy offers excellent exposure. It minimizes the need for cardiac dissection, and thus, the risk for injury. Avoiding a resternotomy increases patient comfort of redo mitral valve surgery.     

Aortic valve repair with minimal access "J" sternotomy

Recently many cardiovascular operations have been performed with minimally invasive cardiac surgery (MICS). It is reported that MICS is superior to standard full sternotomy in regard to cosmetic and post-operative recovery. In our institution, aortic valve repair operations have been performed to aortic valve insufficiency. This time, we performed aortic valve repair by minimal access "J" sternotomy. A 63-year-old male with degenerative aortic regurgitation underwent aortic valve repair by MICS. He had experienced dyspnea on exertion 7 days before admission. Preoperative transthoracic echocardiogram showed the grade of aortic regurgitation (AR) was severe. Surgery was successful and the grade of AR became trivial. This combined procedure have merits for patients because of freedom from anticoagulation and small incision. Such combined surgery may be indicated in the treatment in a subset of patients with degenerative AR.     

Early and late outcomes of 1000 minimally invasive aortic valve operations

OBJECTIVE: Minimal access cardiac valve surgery is increasingly utilized. We report our 11-year experience with minimally invasive aortic valve surgery. METHODS: From 07/96 to 12/06, 1005 patients underwent minimally invasive aortic valve surgery. Early and late outcomes were analyzed. RESULTS: Median patient age was 68 years (range: 24-95), 179 patients (18%) were 80 years or older, 130 patients (13%) had reoperative aortic valve surgery, 86 (8.4%) had aortic root replacement, 62 (6.1%) had concomitant ascending aortic replacement, and 26 (2.6%) had percutaneous coronary intervention on the day of surgery (hybrid procedure). Operative mortality was 1.9% (19/1005). The incidences of deep sternal wound infection, pneumonia and reoperation for bleeding were 0.5% (5/1005), 1.3% (13/1005) and 2.4% (25/1005), respectively. Median length of stay was 6 days and 733 patients (72%) were discharged home. Actuarial survival was 91% at 5 years and 88% at 10 years. In the subgroup of the elderly (> or =80 years), operative mortality was 1.7% (3/179), median length of stay was 8 days and 66 patients (37%) were discharged home. Actuarial survival at 5 years was 84%. There was a significant decreasing trend in cardiopulmonary bypass time, the incidence of bleeding, and operative mortality over time. CONCLUSIONS: Minimal access approaches in aortic valve surgery are safe and feasible with excellent outcomes. Aortic root replacement, ascending aortic replacement, and reoperative surgery can be performed with these approaches. These procedures are particularly well-tolerated in the elderly.     

Minimally invasive reoperative isolated valve surgery: early and mid-term results

OBJECTIVE: Minimally invasive, nonsternotomy approaches for valve procedures may reduce the risks associated with cardiac surgery after prior sternotomy and may improve outcomes. We analyzed our institutional experience to test this hypothesis. METHODS: Between 1995 and 2002, 498 patients with previous cardiac operations via sternotomy underwent isolated valve surgery: 337 via median sternotomy (aortic = 160; mitral = 177) and 161 via mini-thoracotomy (aortic = 61; mitral = 100). Data were collected prospectively using the New York State Cardiac Surgery Report Form. RESULTS: Preoperative incidences of congestive heart failure, renal disease, and nonelective procedures were higher in the sternotomy group. Hospital mortality was significantly lower with the minimally invasive approach, 5.6% (9/161) versus 11.3% (38/337) (univariate, p = 0.04). However, multivariate analysis (odds ratio: 95% confidence intervals, p value) revealed that chronic obstructive pulmonary disease (6.6: 1.4 to 3.1, p = 0.001), renal disease (4.1: 1.52 to 11.2, p = 0.01), cerebrovascular disease (2.2: 1.03 to 4.78, p = 0.04), and ejection faction <30% (1.5: 0.96 to 5.5, p = 0.06) were associated with increased mortality. While mean bypass time, cross-clamp times, and stroke rates were comparable between groups, patients undergoing minimally invasive valve surgery had no deep wound infections (0% vs 2.4%, p = 0.05), less need for blood products (p = 0.02), and shorter hospital stays (p = 0.009). Five-year survival was higher with minimally invasive techniques as compared to a sternotomy approach (92.4 +/- 2% and 86.0 +/- 2%, respectively, p = 0.08). CONCLUSIONS: Reoperative valve surgery can be safely performed using a nonsternotomy, minimally invasive approach, with at least equal mortality, less hospital morbidity, decreased hospital length of stay, and slightly favorable mid-term survival as compared to sternotomy.     

Port-Access mitral valve surgery: summary of results

BACKGROUND: The purpose of this study was to review the short-term results of an initial experience with minimally invasive cardiac valve surgery using the Port-Access approach in terms of feasibility, safety, and reproducibility. METHODS: Between October 1995 and October 1997, 151 minimally invasive cardiac valve procedures were performed at our institution using the Port-Access approach. The patients' mean age was 58.1 years (range 21 to 91 years) and 50% were male. Aortic valve replacement was performed in 35 (23.2%) patients, mitral valve repair in 56 (37.1%) patients, mitral valve replacement in 36 (23.8%) patients, and complex valve procedures in 24 (15.9%) patients. RESULTS: The operative mortality rate for isolated mitral valve surgery was 1.1% (1/92) and for all mitral valve surgery 3.5% (4/113). The operative mortality rate for isolated aortic valve patients was 5.7% (2/35). For the total group the operating mortality was 4% (6/151). Early complications for mitral valve patients included reoperation for bleeding or tamponade in 5 (4.4%) patients, myocardial infarction in 2 (1.2%) patients, and transient ischemic attack and wound infection in 1 (0.1%) patient each. One patient required reoperation for mitral valve failure that resulted in aortic dissection unrelated to the Endoaortic Clamp catheter and ultimately led to death. Two (5.6%) aortic valve patients required reoperation for bleeding and two (5.6%) required reoperation for tamponade. CONCLUSIONS: Minimally invasive Port-Access techniques can be applied to most patients with valvular heart disease with minimal morbidity and mortality and good postoperative valve function and may be the preferred approach for isolated mitral and aortic valve surgery.