Management of patients undergoing multivalvular surgery for carcinoid heart disease: the role of the anaesthetist.

BACKGROUND: The management of patients with carcinoid heart disease poses two major challenges for the anaesthetist: carcinoid crisis and low cardiac output secondary to right ventricular (RV) failure. Carcinoid crises may be precipitated by the administration of catecholamines and histamine-releasing drugs. METHODS: We analysed a series of 11 patients [six males, median (range) age 60 (42-73) yr] with severe symptomatic carcinoid heart disease who underwent multivalve surgery (right-sided valves, n=8; right- and left-sided valves, n=3) between 2001 and 2007. RESULTS: All patients received octreotide intraoperatively [650 (300-1050) microg] to prevent carcinoid symptoms and vasoplegia. Those patients on a greater preoperative octreotide regime required additional intraoperative octreotide [median (range) dose 320 (300-850) vs 750 (650-1050) mug]. Similarly, the use of greater doses of aprotinin (> 5 KIU) was associated with greater requirements for octreotide [475 (300-700) vs 750 (320-1050) microg] and higher glucose levels (> or =8.5 mmol litre(-1)). Catecholamines were generally required in those patients who presented with a worse New York Heart Association functional class. Overall mortality was 18% (n=2) and only one episode of mild intraoperative carcinoid crisis was observed. CONCLUSIONS: Carcinoid crisis and RV failure still remain the primary challenges for the anaesthesiologist while managing patients with carcinoid heart disease. Our study supports the administration of catecholamines to wean patients off cardiopulmonary bypass, particularly in the presence of myocardial dysfunction. Those patients on higher octreotide dosages may require close intraoperative glucose monitoring. Despite high operative mortality, surgical outcome has been improved potentially due to earlier patient referral and better perioperative management.

Automated distal coronary bypass with a novel magnetic coupler (MVP system).

OBJECTIVE: We sought to assess the feasibility of performing sutureless distal coronary artery bypass anastomoses with a novel magnetic coupling device. METHODS: From May 2000 to April 2001, single-vessel side-to-side coronary artery bypass grafting on a beating heart was performed in 39 domestic white pigs (35-60 kg) without the use of mechanical stabilization, shunts, or perfusion bridges. Animals were divided into 2 groups. Seventeen pigs underwent right internal thoracic artery to right coronary artery bypass grafting through a median sternotomy (group 1) with a novel magnetic vascular positioning system (MVP system; Ventrica, Inc, Fremont, Calif). Twenty-two pigs underwent left internal thoracic artery to left anterior descending artery grafting with the MVP anastomotic device through a left anterior minithoracotomy (group 2). This system consists of 2 pairs of elliptical magnetic implants and a deployment device. One pair of magnets forms the anastomotic docking port within the graft; the other pair forms an identical anastomotic docking port within the target vessel. The anastomosis is created when the 2 docking ports magnetically couple. Anastomotic patency was evaluated by means of angiography during the first postoperative week and at 1 month. Histologic studies were performed at different time points as late as 6 months. RESULTS: Right internal thoracic artery to right coronary artery anastomoses and left internal thoracic artery to left anterior descending artery anastomoses were successfully performed with the system in all animals. The self-adherent and self-aligning properties of the implants allowed for immediate and secure approximation of the arteries (total anastomotic time between 2-3 minutes). Anastomoses were constructed without a stabilization platform. Five nondevice-related deaths occurred postoperatively. One-week angiography, performed in 35 surviving animals, showed a patent graft and anastomosis in all cases. The patency rate at 1 month was 97% (33/34). Histologic studies as late as 6 months demonstrated neointimal coverage of the magnets without any significant luminal obstruction. Histology also confirmed the presence of viable tissue between magnets. CONCLUSION: The MVP anastomotic system uses magnetic force to create rapid and secure distal coronary artery anastomoses, which might facilitate minimally invasive and totally endoscopic coronary artery bypass surgery.

Mitral valve repair in redo cardiac surgery.

An increasing number of patients are being referred for mitral valve repair in the redo cardiac surgery setting. The most common clinical scenarios involve prior coronary bypass surgery or aortic valve replacement, each presenting special challenges in terms of gaining valve exposure to enable repair while limiting dissection as much as possible. A right anterior thoracotomy approach is preferred in most patients, coupled with hypothermic fibrillatory arrest. A repeat sternotomy may be favored in select circumstances such as when there is a need for bypass grafting or moderate aortic insufficiency is present. Special attention to cannulation techniques, perfusion conditions, valve exposure, and de-airing maneuvers are all important to ensure good clinical results. Using a tailored approach we have performed mitral valve repair in 22 patients with a patent left internal mammary artery graft following coronary artery bypass grafting between July 1992 and February 2000 with acceptable morbidity and low mortality.

Minimally invasive CABG.

For more than three decades, conventional coronary artery bypass grafting (full sternotomy, cardiopulmonary bypass, and cardioplegic arrest) has been the treatment of choice for patients with multi-vessel coronary artery disease. However, neurologic injury secondary to ascending aortic manipulation and systemic inflammatory reaction related to cardiopulmonary bypass are major causes of morbidity. During the past decade research efforts have been focused on the development of innovative revascularization techniques to minimize these deleterious effects. Minimally invasive direct coronary artery bypass surgery was developed to reduce chest trauma and to accelerate patient recovery. The relatively recent introduction of mechanical stabilizers and positioning devices has allowed for the safe performance of off-pump coronary artery bypass for patients with multi-vessel disease. Robotic technology has offered the possibility of myocardial revascularization through limited access using endoscopic principles. Recently, emphasis has been placed on the development of new sutureless anastomotic devices that may revolutionize the field of myocardial revascularization and allow a broader acceptance of minimally invasive CABG. Despite the increasing availability of new technologies, the validity of these procedures must be evaluated carefully. Prospective randomized studies and longitudinal follow-up will be required.

The preferred approach for mitral valve surgery after CABG: right thoracotomy, hypothermia and avoidance of LIMA-LAD graft.

BACKGROUND AND AIM OF THE STUDY: An alternative to avoid redo sternotomy in patients with patent left internal mammary artery-left anterior descending coronary artery (LIMA-LAD) grafts undergoing mitral valve surgery is right thoracotomy with moderate-deep hypothermia (approximately 20 degrees C) and fibrillatory arrest without aortic cross-clamping. Few reports exist which directly compare re-sternotomy and right thoracotomy. METHODS: Between July 1992 and February 2000, 47 patients (39 males, eight females; median age 66 years; range: 41-83 years; 41 in NYHA class III or IV) with patent LIMA-LAD grafts underwent mitral valve surgery. Thirty-seven patients were approached through a right thoracotomy with moderate-deep hypothermia (median 20 degrees C) and fibrillatory arrest (right thoracotomy group), and 10 were approached through a re-sternotomy, with aortic cross-clamping and cardioplegic arrest. The median ejection fraction was 42% (range: 20-71%). Univariate analysis was used to determine predictors of outcome, as well as to evaluate differences in characteristics between groups. RESULTS: Operative mortality (OM) and perioperative myocardial infarction for the entire cohort was 11% and 10%, respectively, and there were no inter-group differences. No preoperative characteristics were associated with OM. Two LIMA-LAD graft injuries occurred in the re-sternotomy group compared with none in the right thoracotomy group (20% versus 0%, p = 0.04). Transfusion requirements were also greater in the redo sternotomy group (median 7 versus 2 packed red blood cell units, p = 0.04). CONCLUSION: Right thoracotomy with moderate-deep hypothermia and fibrillatory arrest is the preferred approach for reoperative mitral valve surgery after coronary artery bypass grafting in the presence of patent LIMA-LAD grafts. These data suggest that this approach is associated with decreased incidence of LIMA-LAD graft injury, as well as reduced transfusion requirements.

Does coronary artery bypass grafting alone correct moderate ischemic mitral regurgitation?

BACKGROUND: The optimal management of moderate (3+ on a scale of 0 to 4+) ischemic mitral regurgitation (MR) remains controversial. Some advocate CABG alone, whereas others favor concomitant mitral annuloplasty. To clarify the optimal management of these patients, we evaluated the early impact of isolated CABG on moderate ischemic MR. METHODS AND RESULTS: Between January 1992 and August 1999, 136 patients (54% male, mean age 70.5 years, mean New York Heart Association class 2.7, mean ejection fraction 38.1%) with a preoperative diagnosis of moderate ischemic MR, without leaflet prolapse or pathology, underwent isolated CABG. Thirty-eight (28%) of 136 patients had intraoperative transesophageal echocardiography (TEE) before CABG, and 68 (50%) had postoperative transthoracic echocardiography (TTE) within 6 weeks of surgery. The subgroups of patients undergoing intraoperative TEE and postoperative TTE had preoperative characteristics similar to the overall group. The 30-day operative mortality was 2.9% (). Intraoperative TEE downgraded the severity of MR to mild or less (0 to 2+) in 89% (). On postoperative TTE, 40% () continued to have at least moderate MR (3 to 4+), 51% () improved somewhat to mild (2+) MR, and only 9% () had resolution of their MR (0 to 1+). The mean preoperative, intraoperative, and postoperative MR grades were 3.0+/-0.0, 1.4+/-1.0, and 2.3+/-0.8, respectively (P<0.001). CONCLUSIONS: CABG alone for moderate ischemic MR leaves many patients with significant residual MR and may not be the optimal therapy for most patients. Intraoperative TEE may significantly underestimate the severity of ischemic MR. A preoperative diagnosis of moderate MR may warrant concomitant mitral annuloplasty.

New approach for reconstruction of the pulmonary outflow tract during the Ross procedure.

BACKGROUND: This study describes and evaluates the early results of a new surgical technique to reconstruct the right ventricular outflow tract and fit it with a new valve after the Ross procedure. METHODS AND RESULTS: Between March 1996 and November 1997, 20 patients underwent a Ross operation with a new approach consisting of a direct anastomosis between the remaining pulmonary artery trunk and the infundibulum and of the creation of a monocusp tailored from the anterior pulmonary artery wall as a means of reconstructing the valve. The 20 patients (12 males and 8 females) had a mean age of 27.4 years (range, 17 to 42 years). Ten of them had predominant aortic regurgitation, 8 had aortic stenosis, and 2 had mixed disease. There were no deaths during the follow-up period of up to 20 months, no early or late repeat operations, and no specific complications secondary to the surgical technique. During the follow-up, at the aortic autograft site, 19 patients had no or trivial regurgitation, and a mild regurgitation was found in only 1 patient. Across the pulmonary monocusp, color flow Doppler demonstrated no or trivial incompetence in 10 patients, mild incompetence in 7, and moderate incompetence in 3. No significant pressure gradient was shown. CONCLUSIONS: Our experience supports the use of this new surgical procedure and allows extension of the Ross operation to where there are no facilities for homografts. It may be an alternative for right ventricular outflow tract reconstruction with a homograft should the results be confirmed at long-term follow-up.

Lateral approach to femoral bifurcation.

Femoral bifurcation can be approached through a lateral incision in the femoral triangle, passing behind the sartorius muscle and thus leaving undisturbed the femoral lymphatic network. The principal advantage of this route is it limits the local complications that occasionally result in infection of the operative site. This lateral approach is indicated primarily for infrainguinal revascularizations originating from the common femoral artery in patients at high risk for local infection. It should not, however, be used routinely because exposure of the vessels, particularly the medial aspect of the artery and the profundus vessels, is limited. The risks of this route are essentially related to the neural elements encountered during dissection.