On-pump versus off-pump coronary artery bypass grafting: impact on postoperative renal failure requiring renal replacement therapy

BACKGROUND: Despite refinements in perioperative patient management postoperative renal failure requiring hemofiltration or dialysis is still a common complication after coronary artery bypass grafting associated with impaired patient outcome. METHODS: Prospective data on 9,631 patients receiving myocardial revascularization with (coronary artery bypass grafting [n = 8,870]) or without cardiopulmonary bypass (off-pump coronary artery bypass grafting [n = 761]) between April 1996 and August 2001 were evaluated by univariate and multivariate logistic regression analysis. RESULTS: Overall prevalence of postoperative continuous renal replacement therapy was 4.1% (coronary artery bypass grafting, 4.3%; off-pump coronary artery bypass grafting, 1.8%; p = 0.001). Thirty of 40 selected preoperative and intraoperative patient and treatment related variables had a high association with the requirement for postoperative renal replacement therapy; fifteen of these variables were independent predictors in the whole study population. Off-pump coronary artery bypass surgery was identified as having a significantly lower predictive value for postoperative continuous renal placement therapy. In the subgroup of patients undergoing off-pump coronary artery bypass grafting surgery, a second multivariate logistic regression model revealed preoperative cardiogenic shock, urgent operation, intraoperative low cardiac output, and high transfusion requirement as independent predictors for postoperative renal replacement therapy. CONCLUSIONS: Patients with preoperative nondialysis dependent renal insufficiency are at a high risk for further decline in renal function requiring postoperative continuous renal replacement therapy. Off-pump coronary artery bypass surgery is associated with a lower prevalence of postoperative renal replacement therapy after coronary artery bypass grafting.     

Extra-anatomic renal revascularization in patients with renal artery stenosis and abdominal aortic occlusion

Thirteen patients with atherosclerotic renal artery stenosis and total abdominal aortic occlusion underwent extra-anatomic surgical renal revascularization without aortic replacement. Renal artery stenosis was present unilaterally (n = 2), bilaterally (n = 7), or in a solitary kidney (n = 4). Surgical renal revascularization was indicated for treatment of severe hypertension in all patients and for preservation of renal function in 10 patients. The level of abdominal aortic occlusion was suprarenal (n = 3), perirenal (n = 2), or infrarenal (n = 8). All patients had extensive collateral vascular supply to the lower extremities with absent (n = 7) or mild (n = 6) claudication. Surgical renal ervascularization was achieved with hepatorenal bypass (n = 6), mesenterorenal bypass (n = 4), or splenorenal bypass (n = 3). None of the patients underwent concomitant aortic replacement. There were no operative deaths. Postoperatively, hypertension was improved in 10 patients, unchanged in 2 patients, and worse in 1 patient. Renal function was improved in 8 patients, stable in 2 patients, and worse in 3 patients. After surgical renal revascularization, no patient required aortic replacement, while 1 patient underwent extra-anatomic revascularization of the lower extremities. We conclude that some patients with renal artery stenosis and abdominal aortic occlusion can be managed by surgical renal revascularization alone without a more extensive and potentially hazardous aortic replacement. In these patients, extra-anatomic techniques can allow safe and successful surgical renal revascularization while avoiding surgery on the diseased aorta.     

Changing concepts in the surgical management of renovascular hypertension

Summary As newer surgical techniques and concepts have emerged, including revascularization of the totally occluded renal artery and alternatives to aortorenal bypass (hepatic, splenic, or iliac artery to renal artery grafts), our patient population has changed dramatically. Patients with diffuse atherosclerotic disease, bilateral renal artery stenosis, totally occluded renal arteries, and azotemia are more commonly referred for renal revascularization, thereby changing the indications for operation and the results that can be anticipated. Although our results in patients undergoing surgery solely for uncontrollable hypertension or renal failure have been successful, much work needs to be done to improve the results obtained in patients with a combination of uncontrollable hypertension and renal failure.     

Total arterial coronary revascularization and factors influencing in-hospital mortality.

OBJECTIVE: To determine if arterial conduit selection or more efficient arterial revascularization techniques influence in-hospital mortality. METHODS: Data from patients undergoing coronary artery bypass surgery at Royal Melbourne Hospital, Australia, between 1 January 1996 and 30 June 1998 (n = 1681) was collected prospectively. Logistic regression analysis was performed. RESULTS: Independent preoperative predictors of increased in-hospital mortality included renal failure, redo coronary artery surgery and intra-aortic balloon pump use. In-hospital mortality for total arterial revascularization 0.7%, radial artery use 0.9%, pedicled arterial revascularization 0.2%, composite arterial conduit 0.4%, and the exclusive Y graft operation 0.3%. These were all associated with reduced in-hospital mortality. Mortality when vein graft was used was 2.9%. Most patients received total arterial revascularization, which was considered the primary surgical strategy. CONCLUSION: Total arterial revascularization, radial artery use and complex arterial reconstructions were associated with reduced in-hospital mortality. Preoperative renal failure, intra-aortic balloon pump use and redo coronary surgery predicted greater in-hospital mortality.     

Aneurysms of the renal artery: surgical management with special reference to extracorporeal surgery and autotransplantation

27 patients underwent surgical arterial reconstruction for renal artery aneurysms. Hypertension was present in 21 cases. The indication for surgery was the prevention of hemorrhagic rupture in association with hypertension. Extracorporeal surgery was performed 13 times for complex aneurysms involving several branches of the renal artery. Simple autotransplantation was performed 3 times for aneurysms located on the main renal artery. In situ surgery was performed on 11 patients (5 aneurysmectomy-arteriorrhaphies and 7 bypass operations). Results on high blood pressure showed that 10 of the 14 hypertensive patients operated by extracorporeal surgery and/or autotransplantation were cured. 1 delayed nephrectomy was performed in this group and 1 death was observed. 39 of the 46 peripheral anastomoses were patent postoperatively. All patients treated with aneurysmectomy-arteriorrhaphy were cured. In patients treated with bypass operations, 3 thromboses of the bypass and 2 failures on hypertension were observed. Aneurysmectomy and simple arterioplasty are preferred for simple renal artery aneurysms. For complex lesions involving several branches and of an intrarenal location, extracorporeal surgery and autotransplantation represent an effective treatment on hypertension and preservation of kidney function.     

Use of the hepatic circulation for renal revascularization

Aortorenal bypass is the preferred procedure for renal revascularization. Occasionally the aorta cannot be used safely and an alternative procedure is required. Thirty-six patients (21 from the Lahey Clinic and 15 from the Cleveland Clinic) have undergone hepatorenal bypass procedures when confronted with a difficult aorta and right renal artery stenosis. Twenty men and 16 women were operated on and observed from 1 to 9 years. The medical indications for surgery were uncontrollable hypertension in 14 patients, preservation of renal function in eight patients, and a combination of these entities in 14 patients. The surgical indications that required an alternate bypass were diffuse atherosclerotic aortic disease in 24 patients, abdominal aortic aneurysms in six patients, and previous aortic surgery in six patients. Postoperative hepatic function studies were assessed in all patients. No permanent abnormalities of liver function were attributed to surgery. Hypertension was cured or improved in 93% of patients; 7% were unresponsive. Mean creatinine levels were 3.5 mg/dl before operation and 2.1 mg/dl after operation. Renal revascularization was successful in 33 of 36 patients (92%).     

Splenorenal bypass in the treatment of renal artery stenosis: experience with sixty-nine cases

From 1962 to 1984 splenorenal bypass was performed in 69 patients with renal artery disease caused by either atherosclerosis (n = 54) or fibrous dysplasia (n = 15). Renal revascularization was performed to control hypertension in 27 patients, to preserve renal function in nine patients, and for both of these reasons in 33 patients. The mean follow-up interval is 5.4 years. Postoperatively hypertension was cured or improved in 52 of 60 patients (87%); the serum creatine level was improved or stable in 37 of 42 patients (88%) who underwent revascularization to preserve renal function. Postoperative graft thrombosis (n = 2) or stenosis (n = 3) occurred in five patients (7%). Splenorenal bypass is an excellent method of revascularization of the left renal artery, particularly for patients with a troublesome aorta that precludes performance of an aortorenal bypass.     

Revascularization of the right ischemic kidney by gastroduodenal artery

Hepatorenal bypass can successfully accomplish revascularization of the right renal artery when the aorta or the iliac vessels cannot be used for a standard renal bypass or renal autotransplantation. The use of the hepatic circulation can be increased by the gastroduodenal to renal artery bypass procedure. Herein we report a clinical case of severe hypertension in a patient with a solitary functional kidney and an extensive atheromatous alteration of the aortoiliac segment. It has been corrected by means of a gastroduodenal end-to-side renal saphenous vein bypass graft.     

The history and development of direct coronary surgery without cardiopulmonary bypass

The history of direct myocardial revascularization without cardiopulmonary bypass dates to 1961 in the dawn of coronary artery surgery. With the introduction and development of techniques of extracorporeal circulation around the same time, beating heart surgery was largely abandoned. Over the subsequent decades, cardiopulmonary bypass and electromechanical cardioplegic arrest became popular as means of revascularization in a bloodless and motionless field. While coronary artery surgery on the arrested heart remained undisputed for decades, myocardial revascularization on the beating heart was pursued by a few pioneering surgeons around the world, based on the belief that coronary revascularization could be performed equally well without the detrimental effects of cardiopulmonary bypass and electromechanical arrest. Various concepts and techniques developed during the 1980s by these pioneers enabled minimally invasive coronary surgery to be performed in the early 1990s. This break from the mainstream allowed selective myocardial revascularization using a minimal incision and no cardiopulmonary bypass to develop and constructed a base for future extensive revascularizations off-pump. With the subsequent explosion of new techniques for coronary exposure and myocardial stabilization, complete revascularization without cardiopulmonary bypass became possible with consistent results. Emerging from the preview of only a few surgeons just a decade ago, off-pump surgery is currently one of the accepted modalities for complete myocardial revascularization worldwide. This paradigm shift in the approach to myocardial revascularization has led to exiting new future possibilities, such as beating heart totally endoscopic coronary artery surgery.     

Late renal function in patients undergoing renal revascularization for control of hypertension and/or renal preservation

Long-term outcome was studied in 233 patients who had undergone renal artery revascularization (51 with balloon angioplasty, 182 with surgery) between 1976 and 1992. Patients (excluding renal transplants) were treated for renal vascular hypertension without or with renal insufficiency (serum creatinine > 1.6 mg/dl. All patients still alive (n = 188) were contacted to determine current blood pressure, medications, serum creatinine, and subsequent significant medical events. In patients who had died the cause of death was determined and renal function status at the time of death noted from medical records. Some follow-up information was obtained on all 233 patients; follow-up serum creatinine data were obtained in 193 (82.8%) patients. Some 24 patients (10.3%) became dialysis-dependent. Using a multiple logistic regression analysis only, preoperative creatinine maintained significance (P <0.001) for increased dialysis risk. There was no statistically significant association of dialysis for type of revascularization (percutaneous transluminal angioplasty, autogenous artery, saphenous vein, endarterectomy or synthetic material), simultaneous or previous aortic or other vascular surgery (carotid endarterectomy, femoropopliteal bypass, etc.), pathology (atherosclerosis or fibromuscular dysplasia), number of renal arteries stenosed or treated, length of follow-up, age, coronary artery disease, congestive heart failure, stroke, chronic lung disease or type II diabetes. It is concluded that, in patients with renal artery stenosis, the timing of renal artery revascularization relative to the level of renal function is the most important determinant for long-term renal salvage. Copyright © 1996 The International Society for Cardiovascular Surgery.     

Superior mesenterorenal bypass for renal revascularization with infrarenal aortic occlusion

The technique of renal revascularization using a saphenous vein bypass graft from the superior mesenteric artery is described. This operation has been performed for the correction of renal artery stenosis in 4 patients with atherosclerotic aortic occlusion. When the requisite conditions are present, mesenterorenal bypass offers a safe and effective method of renal revascularization, and is preferable to aortic replacement in selected patients.     

On-pump versus off-pump coronary revascularization: evaluation of renal function.

BACKGROUND: Coronary revascularization with cardiopulmonary bypass has the potential risk of renal dysfunction related to the nonphysiologic nature of cardiopulmonary bypass. Recently, there has been a revival of interest in performing myocardial revascularization on the beating heart and we investigated whether this prevents renal compromise. METHODS: A prospective, randomized, controlled trial was performed in 50 patients (45 males, mean age 61+/-3.7 years) undergoing elective coronary artery bypass grafting. Patients were randomly assigned to conventional revascularization with cardiopulmonary bypass (on pump) or beating heart revascularization (off pump). Glomerular and tubular function were assessed up to 48 hours postoperatively. RESULTS: There were no deaths, myocardial infarctions or acute renal failure in either group. Glomerular filtration as assessed by creatinine clearance and the urinary microalbumin/creatinine ratio was significantly worse in the on pump group (p < 0.0004 and 0.0083, respectively). Renal tubular function was also impaired in the on pump group as assessed by increased N-acetyl glucosaminidase activity (p < 0.0272). CONCLUSIONS: These results suggest that off pump coronary revascularization offers a superior renal protection when compared with conventional coronary revascularization with cardiopulmonary bypass and cardioplegic arrest in first time coronary bypass patients.     

The Society of Thoracic Surgeons practice guideline series: transmyocardial laser revascularization

BACKGROUND: Patients with chronic severe angina refractory to medical therapy who cannot be completely revascularized with either percutaneous catheter intervention or coronary artery bypass graft surgery present clinical challenges. Transmyocardial laser revascularization, either as sole therapy or as an adjunct to coronary artery bypass graft surgery, may be appropriate for some of these patients. Although transmyocardial revascularization has consistently been demonstrated as an efficacious means of relieving angina, the mechanism of its effects are still debated, and criteria for the selection of patients for this novel therapy have not been adequately defined. METHODS: We reviewed the available evidence to allow us to make recommendations for the appropriate therapeutic applications of transmyocardial revascularization following the format of the American Heart Association and the American College of Cardiology guidelines for diagnostic and therapeutic procedures. Our recommendations were classified as class I, IIA, IIB, or III. For each recommendation we defined the level of supporting evidence as A, B, or C. RESULTS: We identified class I indications for transmyocardial revascularization as sole therapy and class IIA indications for transmyocardial revascularization as an adjunct to coronary artery bypass graft surgery with levels of evidence A and B, respectively. CONCLUSIONS: Transmyocardial laser revascularization may be an acceptable form of therapy for selected patients: as sole therapy for a subset of patients with refractory angina and as an adjunct to coronary artery bypass graft surgery for a subset of patients with angina who cannot be completely revascularized surgically.     

On-pump versus off-pump coronary artery bypass graft surgery. What do the evidences show?

The main purpose of the off-pump coronary artery bypass surgery is to reduce morbidity and mortality due cardiopulmonary bypass. However, even though many studies have shown that off-pump coronary artery bypass is feasible and provides hospital morbidity and mortality similar to the on-pump coronary artery bypass graft surgery, probably better in some aspects, its long-term results have been questioned, since some trials have shown reduced survival with off-pump coronary artery bypass. It is likely that incomplete revascularization and/or poor graft patency with off-pump coronary artery bypass probably are responsible for such unfavorable outcome.     

Simplified splanchnic artery revascularization using extra-anatomic bypass grafts: a report of ten cases.

Revascularization of the superior mesenteric artery or renal artery is frequently complicated by concomitant atherosclerotic disease in the adjacent aorta. In ten patients, extra-anatomic saphenous vein bypass grafts to the splanchnic vessels were constructed and inflow was obtained from the external iliac artery. All patients recovered without complication and have had functioning grafts on follow-up arteriography. This extra-anatomic bypass provides a simple method for splanchnic artery revascularization.     

Percutaneous coronary intervention in chronic kidney disease patients

Cardiovascular disease (CVD) is the major cause of morbidity and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). The increased prevalence of CVD in patients with renal dysfunction has been attributed to lack of effective prevention and low utilization of effective therapy. The optimal treatment of ischemic heart disease in ESRD patients before renal transplantation is controversial. Although no meta-analysis or pooled analysis of the data from small trials exists, it appears that percutaneous coronary intervention (PCI) provides excellent angiographic success but is associated with increased restenosis and the need for revascularization and that coronary artery bypass grafting (CABG), while associated with higher in-hospital morbidity and mortality, provides better overall long-term results and freedom from angina. Despite suboptimal results for percutaneous interventions in comparison with bypass surgery, PCI remains a viable option, especially for patients who are not candidates for surgery and those with disabling angina despite anti-anginal therapy. Regardless of the revascularization strategy used, outcomes of CABG or PCI in these patients are significantly worse than outcomes in the general population. The long-term benefit after revascularization and adjunctive medical therapy should be an area of intense future research. Studies should also be conducted to investigate the benefit and safety of therapies such as the long-term use of beta-blockers, statins, and renin-angiotensin-aldosterone axis inhibition in patients with CKD.     

One-year outcomes of coronary artery bypass graft surgery versus percutaneous coronary intervention with multiple stenting for multisystem disease: a meta-analysis of individual patient data from randomized clinical trials

BACKGROUND: We aimed to provide a quantitative analysis of the 1-year clinical outcomes of patients with multisystem coronary artery disease who were included in recent randomized trials of percutaneous coronary intervention with multiple stenting versus coronary artery bypass graft surgery. METHODS: An individual patient database was composed of 4 trials (Arterial Revascularization Therapies Study, Stent or Surgery Trial, Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease 2, and Medicine, Angioplasty, or Surgery Study 2) that compared percutaneous coronary intervention with multiple stenting (N = 1518) versus coronary artery bypass graft surgery (N = 1533). The primary clinical end point of this study was the combined incidence of death, myocardial infarction, and stroke at 1 year after randomization. Secondary combined end points included the incidence of repeat revascularization at 1 year. All analyses were based on the intention-to-treat principle. RESULTS: After 1 year of follow-up, 8.7% of patients randomized to percutaneous coronary intervention with multiple stenting versus 9.1% of patients randomized to coronary artery bypass graft surgery reached the primary clinical end point (hazard ratio 0.95 and 95% confidence interval 0.74-1.2). Repeat revascularization procedures occurred more frequently in patients allocated to percutaneous coronary intervention with multiple stenting compared with coronary artery bypass graft surgery (18% vs 4.4%; hazard ratio 4.4 and 95% confidence interval 3.3-5.9). The percentage of patients who were free from angina was slightly lower after percutaneous coronary intervention with multiple stenting than after coronary artery bypass graft surgery (77% vs 82%; P = .002). CONCLUSIONS: One year after the initial procedure, percutaneous coronary intervention with multiple stenting and coronary artery bypass graft surgery provided a similar degree of protection against death, myocardial infarction, or stroke for patients with multisystem disease. Repeat revascularization procedures remain high after percutaneous coronary intervention, but the difference with coronary artery bypass graft surgery has narrowed in the era of stenting.     

Captopril renal scintigraphy--an advance in the detection and treatment of renovascular hypertension

Despite the risks associated with renovascular hypertension and the durable benefits of revascularization, the detection of patients with renovascular hypertension and the selection of those who will benefit from interventional therapy remains a challenge. We have previously documented the reliability of captopril renal scintigraphy in predicting angiographically significant renal artery stenosis in patients suspected of having renovascular hypertension. In the present study we report our recent experience with this noninvasive technique in predicting outcome after revascularization. Captopril renal scintigraphy involves the administration of 50 mg of captopril 3 hours after a baseline technitium-99m diethylenetriaminepentaacetic acid renal scan and 1 hour before a repeat captopril renal scintigraphy scan. Nineteen of the last 70 patients with clinically suspected renovascular hypertension undergoing captopril renal scintigraphy had abnormal renal scan outcomes, and 17 had a decrease in flow or function after captopril (positive captopril renal scintigraphy). Eight of these 17 with abnormal findings on captopril renal scintigraphy underwent revascularization, and the hypertension was cured or improved in six of the eight: two of three after surgical bypass grafting and four of five after angioplasty. In the seven surviving patients with abnormal renal scan results but no change with captopril (negative captopril renal scintigraphy), improvement in hypertension after treatment occurred in only one: one of two after nephrectomy, zero of three after bypass surgery, and zero of two after angioplasty (p less than 0.05). We conclude that captopril renal scintigraphy is an accurate predictor of hypertension response to revascularization. Further evaluation of this new noninvasive technique for assessing patients with suspected renovascular hypertension appears warranted.     

Advances in the treatment of coronary artery disease

Initial pioneering efforts of direct coronary artery bypass were all performed on a beating heart. Although originally introduced into cardiac surgery for the repair of intracardiac defects, the ability of John Gibbon's heart-lung machine to create a motionless, bloodless operative field catalyzed coronary artery bypass surgery. During the ensuing decades tens of millions of patients benefited from coronary revascularization on cardiopulmonary bypass. As we celebrate the 50th anniversary of the invention of the heart-lung machine the landscape of interventional treatment of coronary artery disease has shifted dramatically. Although instrumental in the genesis of the field of coronary revascularization, the role of the heart-lung machine has now diminished. Two thirds of all coronary revascularization is now performed by percutaneous approaches and one fourth of all coronary artery bypass grafting procedures are performed without the heart-lung machine. However owing to the complexity of patients now requiring revascularization as well as recently introduced incremental improvements to cardiopulmonary bypass including coated, low prime circuits, closed integrated systems, and pharmacologic adjuncts Gibbon's heart-lung machine will continue to play an integral role in this field.     

Coarctation of the abdominal aorta: current options in surgical management.

Coarctation or hypoplasia of the abdominal aorta is a rare cause of life-threatening hypertension. In most cases the mechanism of hypertension is elevated blood renin levels secondary to associated renal artery stenosis. Medical control of the hypertension is often difficult, and thus patients usually require renal artery revascularization combined with aortic bypass or replacement early in life. Current surgical management should optimize the use of autogenous methods of renal artery reconstruction including saphenous vein aortorenal bypass, splenorenal arterial anastomosis, hepatorenal saphenous vein bypass, and renal autotransplantation. In selected patients the reconstruction can be staged by correction of the renal artery stenosis and postponement of definitive repair of the aortic coarctation until it becomes hemodynamically significant.