|
|
NewsletterPro: Port-access Cardiac Surgery Is Beneficial Heartport Port-Access cardiac surgery is a form of minimally invasive cardiac surgery developed at Stanford University several years ago and which has become more widely utilized over the past three years. It allows for the institution of cardiopulmonary bypass via specialized catheters placed in the groin or via mini thoracotomy, and the performance of surgery through the small anterior thoracotomy incisions. Purported benefits include enhanced recovery, less post operative pain, shorter hospitalization, faster rehabilitation, and improved cosmesis. Initial clinical work at New York University Medical Center (NYUMC), both in the laboratory and with patients, confirmed the benefits of this approach.(1,2) There has been significant debate in both the surgical and anesthesia communities as to whether this system is being performed at the expense of patient safety. In fact, some centers have abandoned the system due to poor results and difficult experiences. The experience at NYUMC over the past 3 years, however, demonstrates the safety and utility of this system and provides significant advantages for a large portion of patients. Seven hundred and sixty-nine consecutive patients have undergone mini-thoracotomies with CPB for CABG (n=129), isolated valves (n=443), valve/CABG (n=42), and other open procedures (n=79). For this group, the isolated MVR mortality was 1.2%, which compares to the isolated MVR mortality of 3.12% for risk-matched patients from the STS Registry. The incidence of stroke for all patients was 2.5%, compared to 2.53% for risk-matched patients from the STS Registry. The incidence of aortic dissection, 0.3%, compares to 0.11% from the STS Registry for risk-matched patients. No aortic dissections have occurred in the last 400 patients at NYUMC. Additionally, recent results of a study at NYUMC compared Port-Access valve operations to sternotomy valve operations, and yielded beneficial results. Although the bypass time in the Port-Access group was longer than the sternotomy group (139 min vs 110 min), the length of stay for the Port-Access group was less (median of 7 days vs 9 days), the incidence of transfusion requirement was less (52.3% vs 64.8%), and the incidence of sepsis/wound infection was less (0.9% vs 5.7%). (3) The studies mentioned above apply only to NYUMC, but a recent large multicenter study has also yielded good results. An initial data study at 121 institutions with over 1000 patients demonstrated results equal to or better than sternotomy patients. The operative mortality for Port-Access CABG was 1%, vs 2% for sternotomy CABG. The operative mortality of 3.3% for Port-Access valve replacements and 1.5% for Port-Access valve repairs compares favorably to 5.3% and 2.3%, respectively, for sternotomy. Moreover, postoperative atrial fibrillation had an incidence of 5% for Port-Access CABG and 7% for Port-Access valves, versus 17% and 24%, respectively, for sternotomy patients. (4) All of the above cited studies show that Port-Access surgery is a safe and effective alternative to traditional cardiac surgery. However, there are certain caveats to this. First, the proper patients must be selected (i.e. no significant aortic atherosclerotic disease or peripheral vascular disease). Secondly, Port-Access surgery is highly specialized and requires additional training and experience. As with any new procedure there is a learning curve; with increasing experience results improve. Port-Access surgery should be reserved for centers where sufficient numbers of cases are performed and experience obtained. With this experience, in addition to proper patient selection, the Port-Access approach to cardiac surgery is safe and reproducible.
References
1. Schwartz DS, Ribakove GH, Grossi EA, Buttenheim PM, Schwartz JD, Applebaum RM, Kronzon I, Baumann FG, Colvin SB, Galloway AC. Minimally invasive mitral valve replacement: port- access technique, feasibility, and myocardial function preservation. J Thorac Cardiovasc Surg 1997;113:1022-31. 2. Ribakove GH, Miller JS, Anderson RV, Grossi EA, Applebaum RM, Cutler WM, Buttenheim PM, Baumann FG, Galloway AC, Colvin SB. Minimally invasive port-access coronary artery bypass grafting with early angiographic follow-up: initial clinical experience. J Thorac Cardiovasc Surg. 1998;115:1101-10. 3. Grossi EA. Impact of minimally invasive approach on valvular heart surgery: A case controlled study. J Am Coll Cardiol 1999;in press. 4. Galloway A, Shemin R, Glower D, Boyer J, Groh M, Kuntz R,
Burdon T, Ribakove G, Reitz B, Colvin S. First Report of the Port
Access International Registry. Ann Thorac
Surg. 1999; 67:51-8.
Wayne Cutler, M.D. Assistant Professor of Anesthesiology New York University Medical Center New York, NY
The proposed advantages of Port-Access cardiac surgery (less postoperative pain, decreased hospitalization and rehabilitation periods, reduced healthcare costs, etc.) remain unsubstantiated by properly designed prospective investigation and the technique is associated with unique challenges and risks not associated with conventional cardiac surgery. Port-Access cardiac surgery is technically challenging, requires specialized expertise from anesthesiolo-gists and surgeons, and increases OR utilization. Anesthesiologists must be proficient in TEE to guide proper placement of the coronary sinus catheter, pulmonary artery vent catheter, venous drainage cannula, and endoaortic balloon catheter. Proper placement of a double-lumen endotracheal tube (or bronchial blocker) with one-lung ventilation are also required. Surgeons must operate through small incisions and the quality of the surgical results may be suboptimal. It has already been shown that minimally invasive cardiac surgery without CPB (where surgeons must operate through small incisions) is associated with technically suboptimal results (1); in one case report the wrong coronary artery was bypassed (2). Similar technical concerns exist regarding Port-Access cardiac surgery (3-5). The technique does not avoid the known problems associated with conventional hypothermic CPB (neurologic dysfunction, pulmonary dysfunction, renal dysfunction, coagulation disorders, etc.) and exposes the patient and operating room personnel to radiation from fluoroscopy. Furthermore, Port-Access cardiac surgery is associated with unique and potentially lethal risks (aortic dissection, aortic valve trauma, coronary sinus trauma, right ventricular rupture, etc.) not associated with conventional cardiac surgery. Recent data from our institution refutes the claim that Port-Access technology decreases healthcare costs. We retrospectively compared 33 patients who underwent Port-Access CABG with 33 matched patients who underwent conventional CABG. Criteria for matching included surgeon, anesthesiologist, one day prior to surgery or same day admission, lack of preoperative intravenous inotropic or vasoactive medications, use of LIMA, and same time period. When compared to patients undergoing conventional CABG, patients who underwent Port-Access CABG had less total grafts (1.9 vs 3.5, p<0.001), shorter X-clamp times (58 min vs 77 min, p=0.003), and earlier postoperative hospital discharge (4.2 days vs 6.0 days, p=0.011) yet had longer CPB times/graft (63 min vs 31 min, p<0.001), longer OR times (6.8 hr vs 5.4 hr, p<0.001), and increased total cost ($20820 vs $18047, p=0.048). There was no difference between groups in CPB time, extubation time, or ICU time. These findings indicate that although patients undergoing Port-Access cardiac surgery may go home earlier than patients undergoing conventional cardiac surgery, total cost may actually increase because of other factors such as increased OR costs. Many within the medical community are concerned with the quality of the surgical results, increased complexity, and unique risks presented by minimally invasive cardiac surgery with or without CPB (3-5). A recent editorial summarizes the present situation: "Preliminary information is disturbing in regard to anastomotic failures, and we need reassurance that the standard operation is not being compromised in regard to case selection, conduit selection, completeness of revascularization, graft patency rates, and cost. We are waiting for the evidence."(3)
References
1. Gundry SR, et al. Seven-year follow-up of coronary artery bypasses performed with and without cardiopulmonary bypass. J Thorac Cardiovasc Surg 115:1273-1278, 1998 2. Schmid C, et al. Anastomosis to the wrong vessel during off-pump bypass surgery via mini-thoracotomy. Ann Thorac Surg 67:831-832, 1999 3. Bonchek LI, Ullyot DJ. Minimally invasive coronary bypass: A dissenting opinion. Circulation 98:495-497, 1998 4. Baldwin JC. Editorial (con) re: Minimally invasive Port-Access mitral valve surgery. J Thorac Cardiovasc Surg 155:563-564, 1998 5. Reardon MJ, et al. Editorial: Minimally invasive coronary
artery surgery—A word of caution. J Thorac Cardiovasc Surg
114:419-420, 1997
Loyola University |