| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
|
© 2004 European Association of Cardio-Thoracic Surgery
Cardiovascular surgery in patients on chronic dialysis: effect of intraoperative hemodialysisDivision of Cardiovascular Surgery, Aichi Prefectural Owari Hospital, 2135 Kariyasuga Yamato-chou, Ichinomiya 491-0934, Japan
* Corresponding author. Tel.: +81-586-45-5000; fax: +81-586-45-6800 Received August 15, 2003; received in revised form October 17, 2003; accepted November 11, 2003
To evaluate the operative result and the perioperative management of dialysis patients undergoing elective cardiac surgery, we retrospectively reviewed consecutive adult patients with chronic renal failure dependent on maintenance dialysis. Between April 1994 and March 2002, 20 patients who underwent cardiopulmonary bypass (CPB) procedures were studied. Fourteen patients underwent isolated coronary artery bypass grafting, four valve replacements and two combined procedures. Our strategy for the chronic dialysis patients was as follows: dialysis the day before the operation, intraoperative hemodialysis (HD) during CPB, and no dialysis or hemofiltration (HF) on the operative day. Intraoperative HD produces the optimal fluid and electrolyte balance at the end of the operation. The mean interval between the end of surgery and the commencement of HD was 31.2±12.5 h. No patients required any hemocatharsis such as HF or HD on the day of operation. The overall operative mortality was 5.0%. There were six late deaths (30.0%). Overall, including the operative and non-cardiac death, actuarial survival rate was 85.0% at 1 year, 70.0% at 5 years, and 65.0% at 6 years. Intraoperative HD has an advantage in the postoperative period; it avoids the hemodynamic instability and the risk of heparin-associated bleeding associated with the use of HD.
Key Words: Dialysis; Chronic renal failure; End stage renal disease; Cardiac surgery; Intraoperative care
According to the annual report of the Japanese Society for Dialysis Therapy, as of the end of 2002, there were 219 183 dialysis patients in Japan, an increase of 13 049 patients (6.3%) since the end of 2001 [1]. In addition to the advanced age and an increase in the incidence of diabetic nephropathy, the cause of death in at least 32.9% of patients on chronic dialysis is reported to be cardiac [1]. In recent years the number of patients on chronic dialysis undergoing cardiac surgery has risen. The perioperative management of patients on dialysis therapy remains controversial [2]. This study examined the perioperative management and early and late results following cardiac surgery in patients dependent on chronic dialysis.
2.1. Patients Of the patients who underwent cardiovascular surgery between April 1994 and March 2002, 20 patients were on chronic dialysis (Table 1). There were 16 men and 4 women, and their mean age was 58.2 years (range 44–73 years). The major cause of renal failure was diabetic nephropathy. The duration of dialysis before surgery ranged from 0.3 to 20 years (mean 7.1 years). Two patients were maintained on chronic ambulatory peritoneal dialysis (CAPD) and the others on hemodialysis (HD). The operations included isolated coronary artery bypass grafting (CABG) in 14 patients, valve replacement in 4 patients, and CABG plus valve replacement in 2 patients (Table 2).
2.2. Surgical procedures In all patients, surgery was performed under moderate hypothermia at pump flow indexes of 2.2 l/min per m2 and aortic cross-clamping. Cardiac arrest was induced by administrating cold crystalloid cardioplegia (GIK). Myocardial protection was achieved by GIK. 2.3. Perioperative management In all patients, perioperative management was conducted as follows: (1) the final dialysis was performed the day before surgery; (2) during cardiopulmonary bypass (CPB), HD was performed using a dialyzer that was connected to the CPB circuit; (3) after surgery, no hemofiltration (HF) method was used on the operative day; (4) on the first or second postoperative day, HD was performed with nafamostat mesilate as an anticoagulant agent; (5) subsequently, HD switched to typical HD with heparin or peritoneal dialysis.2.4. Follow-up Data for long-term follow-up were collected from patients' medical records and from telephone interviews with patients and relatives. Long-term follow-up was complete for all patients.2.5. Statistical analysis The data are presented as the mean±standard deviation (SD) or the mean with the range. Changes are assessed using one-way repeated measures ANOVA followed by Bonferroni/Dunn tests with the use of the Stat View (Abacus Concepts) statistical software program on a Macintosh computer. A probability value <0.05 was considered to be statistically significant. The cumulative survival rate was calculated using the Kaplan–Meier method. Operative mortality included deaths occurring within 30 days of the operation or during the same hospitalization.
3.1. Operative and early results The aortic cross-clamp time ranged from 60 to 208 min, with a mean of 120 min. The CPB time was 197±43 min. There was one operative death and operative mortality was 5.0% (Table 3). She died 24 days after surgery of sepsis following mediastinitis caused by methicillin-resistant Staphylococcus aureus.
In 9 of the 20 patients (45.0%), one major and eight minor complications arose (Table 3). The one major complication occurred in one fatality. The minor complications included transient seizures in three patients, two cases of gastro-intestinal bleeding and one case each of drainage of a pleural effusion, pericardial effusion, and bleeding from the insertion site of intraaortic balloon pump. No patient needed a second thoracotomy for bleeding. Postoperative duration of mechanical ventilation was 21±12 h (range 3.5–51 h) in all patients and total stay in the intensive care unit was 5.3±2.2 days (range 2–10 days). Early angiographic studies were performed in the patients who underwent CABG. The graft patency rate was 97.0% (32 out of 33 in 15 patients). 3.2. Late results The postoperative follow-up was complete for all patients, ranged from 0.07 to 7.9 years (mean 3.2±2.7 years). Among the 19 survivors, there were six late deaths. Two patients died of pneumonia 90 days and 5.4 years later. Two patients died from arrhythmia 8 months and 1.7 years later. One patient died suddenly 1.9 years after operation. One patient died from complication of the renal implantation 1.5 years after operation. Overall, including the operative and non-cardiac deaths, the actuarial survival was 85.0% at 1 year, 70.0% at 5 years and 65.0% at 6 years.3.3. Perioperative management The changes in blood urea nitrogen (BUN), serum creatinine (Cre), and serum potassium (K) are shown in Table 4. HD performed the day before the operation kept all levels low before the operation. However, all these levels were significantly lower immediately after the operation due to intraoperative dialysis during CPB. Postoperative serum potassium levels were managed by glucose-insulin therapy. CAPD was resumed in the patients on CAPD on the day of surgery. No patients required hemocatharsis, such as HF or HD, on the operative day, including the operative deaths. HD was resumed on the 1st postoperative day (POD) in 8 patients (40.0%) and on the 2nd POD in 12 patients (60.0%). Thus, 12 patients (60.0%) did not require interventional hemocatharsis for 2 days. The mean interval between the end of surgery and the commencement of HD was 31.2±12.5 h (range 17.6–49).
Ten patients (50%) could be extubated before resuming HD. Among recent consecutive eight patients, seven (87.5%) were extubated without HD. In the first patient in our series, we experienced increased chest tube drainage on the second postoperative HD with heparin. Subsequently, nafamostat mesilate was used as an anticoagulant instead of heparin for HD the first few times postoperatively, and there had been no bleeding problems.
Chronic renal failure patients dependent on dialysis require special management in the perioperative period for CPB surgery. In recent reports on the perioperative management of chronic dialysis patients, the strategy—preoperative dialysis the day before the operation, intraoperative HF, and HD on the 1st postoperative day—is common [2]. Variations, such as HD on two consecutive days before the operation [3] or continuous HF begun just after the operation [3,4] are recommended as needed. Intraoperative HF during CPB is the most popular procedure in many institutions [2–5]. As to intraoperative management, Nakayama et al. [2], demonstrated that HF is efficient in the management of fluid and electrolyte balance during CPB, although it is inferior to HD. Ko et al. [6] reviewed 32 reports on a variety of cardiopulmonary procedures performed on renal failure patients published in the English-language literature (1968–1991). They denied the necessity of intraoperative dialysis. However, the use of intraoperative HD was advocated by some groups [7–9] and has become widespread in several institutions and produces good results. Recently Frenken et al. [7] demonstrated their excellent experience with operative mortality 4.4% in 45 patients achieved by using of intraoperative HD. In our institution, intraoperative HD using a parallel circuit connected to the reservoir of the CPB circuit is used routinely, as it is an easy procedure. And availability of the dialysis equipment is not a problem. In our series intraoperative HD during CPB apparently reduces the BUN, Cre, K, and over hydration. Immediately postoperatively, all these levels were significantly lower than preoperative values. We believe intraoperative HD produces the optimal fluid and electrolyte balance at the end of the operation. On the day of surgery, potassium management, which is very important, is feasible using conservative therapy, such as glucose-insulin therapy, if necessary. No patients required hemocatharsis, such as HF or HD, on the day of surgery. It is advantageous to be able to avoid interventional therapy on the day of surgery, if the circulation is unstable or there is a risk of bleeding. As the duration of CPB is reduced, it becomes important to increase the efficiency of hemocatharsis. HD is more efficient than HF. Our average ventilator time of 21 h compared similarly with those reported by Franga and associates [8] (3.8 days), and Horst and colleagues [10] (1.8 days) in dialysis-dependent patients. Recently, larger series of successful cardiac operations have been published [2,5,6,8,10,11]. The operative mortality of patients with chronic dialysis undergoing cardiovascular surgery is reported to range from 2.6 to 14.6% [2–5,8–13]. Dacey [11] underwent a prospective regional cohort study in isolated 15 574 CABG patients in Northern New England from 1992 to 1997. Overall, 283 (1.8%) of the patients were on dialysis and their hospital mortality was 12.1%. Ko et al. [6] reviewed an early postoperative mortality of 9% in 296 cases. Recently, Horst and colleagues [10] summarized the result for 863 patients over 30 years by overview of the available literature including Ko's overview. That shows an overall perioperative mortality rate of 12.5%. In our series, the operative mortality was 5.0%, which is comparable with those in the widely variable range of these previous reports. The rate is reported to be better in elective cases. Therefore, to improve the results of surgery in dialysis patients, elective surgery is recommended before the condition deteriorates [10]. An early referral to surgery (before the onset of congestive heart failure) is important. The incidence of postoperative complications is reported to range from 7.4 to 75% [3,4,8,14]. By Fanga, 73% of CABG in dialysis patients experienced some type of complication [8]. He recognized that postoperative bleeding has been as a common problem after CABG in dialysis patients and reported their rate of 7% in 44 patients. Bleeding tendency might be explained by homeostasis disturbances and anticoagulation during dialysis. To maintain an adequate red cell mass, control periopetative bleeding and in the timing and route of perioperative dialysis is important [13]. Two of our patients had minor bleeding. Postoperative bleeding was minimized by the use of nafamostat mesilate as an anticoagulant for HD [2–4]. Additionally, infections are more common because of a decreased chemiotaxis, lymphopenia, decreased cell-mediated immunity, reduction of interferon and monocyte function [15]. In our series, infection was the most important complication causing operative death. Postoperative survival rates from 90 to 74% at 1 year [2,4,5,7,13,14] and 71 to 55.8% at 5 years [2,3,7,11,13] have been reported. Long-term survival of our patients (hospital mortality included 85% at 1 year, and 70% at 5 years) was comparable to these reports. These rates are relatively poor, although they are acceptable, given that the 1-year mortality of chronic dialysis patients is 9.3% [1]. The leading cause of death in chronic dialysis patients is cardiac failure, and the fifth most common cause is myocardial infarction [1]. Many studies [12,14] have shown that the main cause of death in dialysis patients over the long term is cardiac. As mentioned earlier, patients with renal failure are prone to infection [6,15]. The second cause of death (16.3%) in chronic dialysis patients is infection in Japan and the number is increasing [1]. In our study two of the six late deaths (33%) resulted from infection. Careful management to prevent and control infection is therefore important to improve the results of cardiovascular surgery for dialysis patients. In our institute since August 2000 the number of CABG done using off-pump bypass (OPCAB) is increasing. This may alter the strategy and improve the results of the CABG in dialysis patients because many of the complications related to the use of CPB (bleeding, fluid overload, cerebrovascular accidents) would be avoidable. The limitations of this study should be noted. (1) The number of the patients enrolled was relatively small, (2) the operations included elective surgery in all patients, (3) this study was retrospective and observational study, and (4) the study did not provide a comparison between outcomes of the use of intraoperative HD and those of the use of intraoperative HF.
Patients with chronic renal failure can undergo cardiac surgery with an acceptable operative risk and long-term results. Our strategy, intraoperative HD for chronic dialysis patients, has an advantage to avoid the hemodynamic instability and the risk of heparin-associated bleeding, which provides excellent results.
ICVTS on-line discussion Author: Dr. Hotoshi Hirose, Juntendo University Hospital, Cardiovascular Surgery, 2300 Overlook Rd #312, Cleveland, OH 44106, USA Date: 10-Dec-2003 Message: This paper is somewhat interesting because it supports that the intraoperative hemodialysis has an advantage in postoperative water and electrolyte balance. The authors analyzed a relatively small number of the patients who underwent exclusively on-pump open heart surgery, knowing the fact of the acute increase in the number of off-pump coronary artery bypass performed in chronic hemodialysis patients. Questions for the authors are whether intraoperative hemodialysis for the patients who undergo off-pump CABG should be performed or not. Arguments may exist. Some may say intraoperative hemodialysis is not needed because off-pump bypass provides more hysiological condition than on-pump dose. Others may say intraoperative hemodialysis may optimize the postoperative water and electrolyte balance, as the authors presented in this paper. If yes, what kind of blood access should be performed and how long should the dialysis be? Author: Dr. Fernando Hornero, Consultant Surgeon, Hospital General Universitario, Department of Cardiac Surgery, Av/Tres Cruces s/n, Valencia, 46014 Spain Date: 30-Dec-2003 Message: Doctor Miyahara and his colleagues are to be congratulated for an excellent study and certainly very good results in a very challenging group of patients. In our experience, with dialysis the day before surgery, most of the patients need haemofiltration the first postoperative day. In order to help us to take care of these types of patients, by providing more useful information for the decision making process, I would like to know, which were your criteria for patient selection, especially for those with a probable short cardiopulmonary bypass time. In addition, I would be interested in knowing if your group has experience with prophylactic dialysis in patients with nondialysis-dependent moderate renal dysfunction. Response Author: Dr. Ken Miyahara, Owari Prefectural Hospital, Department of Cardiovascular Surgery, Kariyasuga 2135, Yamato-chou, Ichinomiya 491-0934, Japan Date: 06-Jan-2004 Message: Thank you very much for your attention to our study. As to the patient selection, your first question, we have no clear-cut criteria on cardiopulmonary bypass (CPB) time. In our recent experience the minimum CPB time was 80 minutes. Our perfusionist mentions that HD can be performed and efficient even if the CPB time is less than 60 minutes because high flow HD can be achieved by using a dialyzer that is connected to the CPB circuit. During CPB, hemodynamics are stable and HD can be performed safely. Also, in Japan, the cost of HD is not very expensive. At this moment we are using intraoperative HD for all patients on maintenance dialysis who require CPB surgery. Of course we do not perform intraoperative HD for OPCAG patients. As to the second question, it is important and difficult to answer. In our small number of experience more than half or more of such patients who have renal insufficiency that does not require dialysis before operation needed dialysis during the perioperative period. According to Nakayama et al. [1], 31% of the severe renal dysfunction group (preoperative serum creatinine level > 2.0 mg/dl, nondialysis-dependent before operation) were required to go on hemodialysis after CABG. We have no experience and cannot answer whether prophylactic intraoperative HD is essential or not for such patients. However, prophylactic intraoperative HD might bring benefits if it avoids the postoperative HD which causes the hemodynamic instability and the risk of heparin-associated bleeding in the immediate postoperative period. Reference [1]Nakayama Y, Sakata R, Ura M, Itoh T. Long-term results of coronary bypass grafting in patients with renal insufficiency. Ann Thorac Surg 2003; 75: 496–500. doi:10.1016/S1569-9293(03)00261-5
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
Top
Abstract
1. Introduction