Pulmonary artery banding for hemi-truncus arteriosus in adulthood.

Anomalous origin of the right pulmonary artery from the ascending aorta, also called hemi-truncus arteriosus, is a rare congenital cardiovascular malformation. Around 95% of the reported cases with hemi-truncus arteriosus present in infancy. We describe a case of a 41-year-old female presenting with a long-standing history of intermittent haemoptysis. Cardiac catheterisation confirmed the diagnosis of hemi-truncus arteriosus. The definitive treatment of hemi-truncus arteriosus in adulthood is an extremely high-risk procedure. We decided to perform palliative right pulmonary artery banding which represents a simple but effective procedure for the management of this complex condition.

Use of Contegra conduit reinforced with Goretex as a modified left Blalock-Taussig shunt.

This is the first report of the construction of a modified Blalock-Taussig shunt using a Contegra conduit reinforced with Goretex in a 4-year-old boy. The patient had a complex cardiac history with a primary diagnosis of pulmonary atresia, hypoplastic right ventricle (RV) and RV-coronary artery fistula.

Electrophysiological mapping and ablation of intra-atrial reentry tachycardia after Fontan surgery with the use of a noncontact mapping system.

BACKGROUND: Atrial tachyarrhythmias are a complication of Fontan surgery. Conventional electrophysiological mapping and ablation techniques are limited by the complex anatomic and surgical substrate and a high arrhythmia recurrence rate. This study investigates the use of noncontact mapping to identify arrhythmia circuits and guide ablation in Fontan patients. METHODS AND RESULTS: Eleven arrhythmias were recorded in 6 patients. Noncontact mapping improved recognition of the anatomic and surgical substrate and identified exit sites from zones of slow conduction in all clinical arrhythmias. Radiofrequency linear lesions were targeted across these critical zones in 5 patients. One patient underwent surgical cryotherapy. Although immediate success was achieved in 3 of 5 patients with radiofrequency ablation, 2 patients had a recurrence after a mean of 6.4 months of follow-up. The patient who underwent cryoablation remains free of arrhythmias. CONCLUSIONS: Noncontact mapping can identify arrhythmia circuits in the Fontan atrium and guide placement of ablation lesions. Arrhythmia recurrence is high, possibly because of inadequate lesion creation rather than inaccurate mapping and lesion targeting.

The effect of dietary polyunsaturated fatty acids (PUFA) on acute rejection and cardiac allograft blood flow in rats.

For six weeks, recipient (Lewis RT11) and donor rats (LBNF11/n) were fed three diets that varied only in their lipid content. Diet A (MO) contained 19.5% menhaden oil and 0.5% safflower oil and was rich in omega 3 PUFA; diet B (SO) was 20% safflower oil rich in omega 6 PUFA; and diet C (BT) was 20% beef tallow rich in omega 9 monounsaturated fatty acids and saturated fat. In the first set of graft survival studies a group fed laboratory chow was included (CHOW). Heterotopic cardiac transplantation from donor to recipient animals was performed after the six-week feeding period. The effect of these diets on cardiac allograft survival, mixed lymphocyte response, and blood flow in the rejecting grafts was investigated. The median graft survival in days was significantly prolonged in the rats maintained on either MO (12 days) or SO (14.5 days) compared with the BT (8 days)-or lab chow (7.5 days)-fed animals (P < 0.05). Cyclosporine (CsA) administered at subtherapeutic levels further increased the differences between the PUFA-fed animals and the BT-fed group. The myocardial blood flow of the rejecting allografts was measured using an 85Sr-labeled microsphere technique on the fifth posttransplant day. Flow was greatest in the MO-fed group, and both MO and SO groups had significantly higher myocardial blood flow than BT-fed rats (P < 0.05) or those bearing isografts. The allogenic mixed lymphocyte responses of peripheral blood mononuclear cells (PBMC) and splenic lymphocytes were suppressed in MO- and SO-fed groups compared with BT-fed animals. The immunosuppressive effect of dietary PUFA warrants further investigation, and their use as a possible adjunctive treatment in organ transplantation should be considered.

Comparison of connexin 43, 40 and 45 expression patterns in the developing human and mouse hearts.

The mouse is currently widely used as a model organism in the analysis of gene function but how developmentally regulated patterns of connexin gene expression in the mouse compare with those in the human is unclear. Here we compare the patterns of connexin expression in the heart during the development of the mouse (from embryonic day 12.5 to 6 weeks postpartum) and the human (at 9 weeks gestation and adult stage). The extent of connexin43 expression in the ventricles progressively increased during development of the mouse heart. The developmental pattern of expression for connexins 40 and 45 in the mouse heart was similar, but not identical, and in the ventricles showed a progressive and preferential expression in the conduction system. In general, these dynamic changes of connexins 43, 40 and 45 during mouse cardiac development appear to be mirrored in the human.

Pediatric tracheal homograft reconstruction: a novel approach to complex tracheal stenoses in children.

PURPOSE: Tracheal stenosis can be a life-threatening problem in children. Long-segment tracheal stenosis and recurrent tracheal stenosis are especially problematic. Tracheal homograft reconstruction represents a novel therapeutic modality for these patients. METHODS: Cadaveric trachea is harvested, fixed in formalin, washed in thimerosal (Methiolate), and stored in acetone. The stenosed tracheal segment is opened to widely patent segments proximally and distally. The anterior cartilage is excised and the posterior trachealis muscle or tracheal wall remains. A temporary silicone rubber intraluminal stent is placed and absorbable sutures secure the homograft. Regular postoperative bronchoscopic treatment clears granulation tissue. The stent is removed endoscopically after epithelialization over the homograft. Twenty-four children with severe tracheal stenosis (age 5 months to 18 years, mean +/- standard error of the mean = 8.18 +/- 1.21 years) underwent tracheal homograft reconstruction. All but one had had previous unsuccessful reconstructive attempts. Ten lesions were congenital, nine were posttraumatic, and five were due to prolonged intubation. RESULTS: Follow-up ranged from 5 months to 10 years (3.79 +/- 0.70 years). Twenty patients survive (20/24 = 83%), 16 without any airway problems. Four patients are still undergoing treatment. One patient requiring emergency extracorporeal membrane oxygenator support before the operation died 10 days after tracheal homograft reconstruction. Another patient with severe preoperative mediastinal sepsis died 3.5 months after tracheal homograft reconstruction. Two patients with functional airways died late of unrelated problems. CONCLUSIONS: Tracheal homograft reconstruction demonstrates encouraging short-term to medium-term results for children with severe recurrent tracheal stenosis. Postoperative bronchoscopic and histologic studies provide evidence of epithelialization and support the expectation of good long-term results.

The failing Fontan circulation: successful conversion of atriopulmonary connections.

OBJECTIVES: Symptoms from low cardiac output or refractory atrial arrhythmias are complicating atriopulmonary (classical) Fontan connections. We present our experience of converting such patients to total cavopulmonary connections with and without arrhythmia surgery. METHODS: Between 1997 and 2002, 15 patients (mean age, 19.7 +/- 7.0 years) underwent conversion operations 12.7 +/- 3.5 years after atriopulmonary Fontan operations. Preoperative New York Heart Association functional class was I in 2 patients, II in 2 patients, III in 6 patients, and IV in 5 patients. Four patients underwent intracardiac lateral tunnel conversion alone, and 11 received extracardiac total cavopulmonary connection, right atrial reduction, and cryoablation. RESULTS: No mortality occurred. One patient had conduit obstruction in the immediate postoperative period requiring replacement, and another required a redo operation for endocarditis. Average hospitalization was 17.9 +/- 9.38 days; chest drains were removed on median day 4 (range, 1-29; mean, 7.4 +/- 7.58 days). At follow-up (mean, 42.6 +/- 22.1 months), late atrial arrhythmias had recurred in 3 of 4 patients with intracardiac total cavopulmonary connections (without ablation) and 1 of 11 patients with extracardiac total cavopulmonary connections with ablation. All patients are in New York Heart Association class I or II. Exercise ability (Bruce protocol) improved 69% from a mean of 6.18 +/- 4.01 minutes to 10.45 +/- 2.11 minutes (P <.05). Need for antiarrhythmic agents decreased postoperatively (patients receiving < or =1 antiarrhythmic: 9 preoperatively vs 15 at long-term follow-up, P <.05). No patient has required transplantation. Protein-losing enteropathy, which was present in 1 patient, improved transiently with conversion. There was 1 late death from gastrointestinal hemorrhage. CONCLUSIONS: Fontan conversion can be achieved with low mortality and improvement in New York Heart Association class and exercise ability. Concomitant arrhythmia surgery reduces the incidence of late arrhythmias.

Aortic root replacement in patients with Marfan's syndrome: the Southampton experience.

BACKGROUND: The purpose of this study was to evaluate the early and late clinical outcome after aortic root replacement (ARR) in patients with Marfan's syndrome. METHODS: A total of 65 consecutive patients with Marfan's syndrome (mean age 41.7 +/- 10.7 years, range 15 to 76 years) undergoing ARR between 1972 and 1998 in Southampton were studied. Of the patients, 45 had a chronic aneurysm of the ascending aorta and 20 had a type A dissection (16 acute and 4 chronic). The operations were elective in 38 and nonelective in 27 cases (emergency in 22 and urgent in 5). Mean size of the ascending aorta was 6.3 +/- 1.4 cm (3.8 to 12 cm). A Bentall procedure was performed in 62 and a homograft root replacement in 3 patients. Mean follow-up was 8 +/- 4.1 years (0 to 22.9 years). RESULTS: Operative mortality was 6.1% (4 deaths) (for the elective vs nonelective procedures it was 2.6% vs 11%, p = 0.2). The 10-year freedom from thromboembolism, hemorrhage, and endocarditis was 88%, 89.8%, and 98.4% (0.9%, 0.9%, and 0.2% per patient-year) and from late aortic events it was 86.3% (1.3% per patient-year). Aortic root replacement for dissection was an independent predictor of occurrence of late aortic events (p = 0.01). Five patients had a reoperation with one early death. The 10-year freedom from reoperation was 89.2% (1.1% per patient year) (for elective and nonelective procedures, 90.8% vs 84.6%, p = 0.6). The 10-year survival, including operative mortality, was 72.7% (for elective and nonelective procedures, 78% vs 66.5%, p = 0.6). Late aortic events was an independent adverse predictor of survival (p = 0.02). CONCLUSIONS: In patients with Marfan's syndrome, elective ARR, usually for chronic aneurysm, is associated with a low mortality, low rate of aortic complications, and good late survival. Nonelective ARR, mostly for dissection, has a greater operative risk and a significantly higher incidence of late catastrophic aortic events. Early prophylactic surgery in these patients is therefore recommended. Long-term clinical and radiologic follow-up to prevent or to treat late aortic events is highly desirable.

Ventricular thrombosis and systemic embolism in bodybuilders: etiology and management.

Increased thrombogenicity and acute embolism are well-recognized complications of chronic anabolic steroid abuse. The following cases highlight such dangers in steroid-enhanced bodybuilders who developed intracardiac thrombosis that subsequently embolized. Systemic anticoagulation and surgical thrombectomy constituted the mainstay treatment. This represents the first report of such devastating cardiovascular complications after anabolic steroid abuse and their management.

Open commissurotomy for critical isolated aortic stenosis in neonates.

BACKGROUND: The optimal management of critical aortic stenosis in early infancy remains controversial. The aim of this study was to assess the early and late outcomes following open surgical valvotomy for critical aortic stenosis in neonates and to provide a framework of data against which current results of other treatment approaches can be evaluated. METHODS: Eighteen consecutive neonates (mean age 9.2 days, range 1 to 26 days) undergoing an open valvotomy for critical isolated aortic stenosis (the standard treatment for this condition in our unit) between 1984 and 2000 were studied. The mean aortic valve gradient was 79.4 mm Hg. Twelve neonates received prostaglandins and 10 received inotropic agents preoperatively. Follow-up was complete (mean 8.1 years, range 1 month to 15 years). RESULTS: There was no operative mortality. At discharge, the mean aortic valve gradient was 37.2 mm Hg, with 6 patients having mild and 2 having moderate aortic regurgitation. Six patients required a reoperation; 3 of these had an aortic valve replacement at 9 to 11 years of age. Kaplan-Meier 5- and 10-year freedoms from any aortic reoperation or reintervention were 85 and 55%, respectively; 5- and 10-year freedoms from aortic valve replacement were 100 and 79%, respectively. A 14-year-old boy died from endocarditis 4 years following an aortic valve replacement in another unit. Kaplan-Meier 10-year survival was 100%. All survivors are in New York Heart Association I class and are leading normal lives. Their mean aortic valve gradient is 34.5 mm Hg, and none has significant aortic regurgitation. CONCLUSIONS: Open valvotomy for critical aortic stenosis in neonates carries a low operative risk and provides lengthy freedom from recurrent stenosis or regurgitation. Reoperations are inevitable, but aortic valve replacement can be delayed until the implantation of an adult-sized prosthesis is possible. Late survival is excellent. We consider open surgical valvotomy to be the treatment of choice for critical neonatal aortic stenosis.

A single-center experience with 1,378 CarboMedics mechanical valve implants.

BACKGROUND: The CarboMedics bileaflet prosthetic heart valve was introduced in 1986. We first implanted it in March 1991. The purpose of this study was to analyze our clinical experience with this valve. METHODS: Between March 1991 and December 1997, 1,378 valves were implanted in 1,247 patients, 705 men (56.5%) and 542 (43.5%) women with a mean age of 62 +/- 11.9 years (+/- the standard deviation). Follow-up is 99% complete and totals 3,978 patient-years. RESULTS: The early mortality rate was 4.4% (55/1,247). The survival rates at 1 year and 5 years were 91.8% +/- 0.8% (+/- the standard error of mean) (n = 1,062) and 79.2% +/- 1.4% (n = 281), respectively. Freedom from valve-related complications (linearized rate, 4.9% per patient-year) at 1 year and 5 years was 90.6% +/- 0.8% (+/- the standard error of the mean) (n = 996) and 80.6% +/- 1.4% (n = 243), respectively. Linearized rates for various complications were as follows: bleeding events, 1.73% per patient-year; embolic events, 1.76% per patient-year; operated valvular endocarditis, 0.18% per patient-year; valve thrombosis, 0.10% per patient year; and nonstructural dysfunction, 1.21% per patient-year. Freedom from reoperation at 1 year and 5 years was 98.6% +/- 0.3% (+/- the standard error of the mean) (n = 1,070) and 97.7% +/- 0.5% (n = 285), respectively. CONCLUSIONS: Midterm results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.

Successful complete tracheal resection in a three-month-old infant.

We report an infant with severe long-segment tracheal stenosis in whom the posterior trachea was formed by complete cartilage rings and the anterior trachea was almost totally formed by a solid cartilage plate. The child was successfully treated initially by complete resection of the trachea and primary end-to-end repair and subsequently with tracheal homograft transplantation for secondary stenosis.

Potential of parenteral and enteral nutrition in inflammation and immune dysfunction: a new challenge for dietitians.

Advances in the understanding of the interrelationship between immunology and nutrition indicate that immune dysfunction in critically ill patients is linked with nutrient deficiency and abnormal acute-phase response to illness. Immune dysfunction requires special nutrition therapy and metabolic support; immunoregulation by nutrition manipulation may lead to specific immunotherapies for defined groups of patients. The success of dietary strategies must be measured not only by metabolic indexes but also by effects on immune function. The health profession must combat immune dysfunction and inflammation for the sick and frail patients under its care.

Surgical treatment of infective mitral valve endocarditis: predictors of early and late outcome.

BACKGROUND AND AIMS OF THE STUDY: The study aim was to review our experience in surgical treatment of infective mitral valve endocarditis, and to identify predictors of early and late outcome. METHODS: Ninety-one consecutive patients (52 males, 39 females, mean age 55.6 years) underwent surgery between 1973 and 1997 for endocarditis of isolated mitral (n = 65, 71%), mitral and aortic (n = 25, 28%) and mitral, aortic and tricuspid valves (n = 1, 1%). Native valve endocarditis (NVE) was present in 60 patients (66%) and prosthetic valve endocarditis (PVE) in 31 (34%). The main indications for surgery were heart failure in 32 patients, valve dysfunction in 23, vegetations in 21, and persistent sepsis in 11. Eighty-six patients (95%) were in NYHA classes III-IV, and 58 (64%) had active culture-positive endocarditis at surgery. Mechanical valves were implanted in 73 patients and bioprosthetic valves in 13; valves were repaired in five patients. The impact of 46 parameters on early and late outcome was defined by means of univariate and multivariate statistical analysis. Follow up was complete (mean 5.5 years; range: 0-23.1 years; total 507.3 patient-years). RESULTS: Operative mortality rate was 11% (n = 10). Recurrent infection was recorded in five patients (6%), and reoperation was required in eight (9%). Freedom from recurrent infection and reoperation at 10 years was 89.1% and 87.8% respectively. There were 22 late deaths, 15 from cardiac causes. Actuarial survival rates for all patients at 5, 10 and 15 years were 73.0%, 62.7% and 58.7% (for hospital survivors, the corresponding rates were 81.9%, 69.7% and 66.0%). On multiple logistic regression and Cox proportional hazards models, the following were independent predictors: preoperative pulmonary edema (p = 0.01) for operative mortality; PVE (p = 0.02) for recurrence; younger age (p = 0.02) and PVE (p = 0.02) for reoperation; male gender (p = 0.004) and longer ITU stay for survival (if all patients were included); male gender (p = 0.01) and myocardial invasion by infection (p = 0.02) for survival (if only the hospital survivors were analyzed). CONCLUSION: Surgery for infective mitral valve endocarditis carries a relatively high, though acceptable, risk but provides satisfactory freedom from recurrent infection, reoperation and improved long-term survival. Analysis of these data demonstrated that the preoperative hemodynamic status was the major predictor of in-hospital outcome, PVE increased the risk for recurrent infection and reoperation, whereas male gender and myocardial invasion by the infective process critically reduced the probability of long-term survival. The type of offending pathogen, the activity of infection and the involvement of more than one valve did not appear to influence early and/or late outcome.

Aortic valve replacement for endocarditis: determinants of early and late outcome.

BACKGROUND AND AIM OF THE STUDY: The study aim was to determine risk factors for operative mortality, recurrent infection, reoperation and long-term survival following aortic valve replacement (AVR) for infective endocarditis. METHODS: Between 1973 and 1997, 109 patients (91 male, 18 female, mean age 52.6 years) underwent isolated AVR for infective endocarditis in our unit. Native valve endocarditis was present in 89 (81.6%) and prosthetic valve endocarditis in 20 (18.4%). Active culture-positive endocarditis was present in 53 (48.6%). Preoperatively, 99 patients (90.8%) were in NYHA classes III and IV. Indications for surgery included cardiac failure in 41 patients, valvular dysfunction in 38, vegetations in 18, sepsis in seven, abscess in six and embolism in four. Mechanical valves were implanted in 69 patients (63.3%) and bioprostheses in 40 (36.7%), including a homograft in 19 (17.4%). Follow up was complete (mean 5.8 years; range: 0-23.8 years; total 633.5 patient-years). RESULTS: The operative mortality was 10.1% (11 deaths). At ten years, freedom from recurrent infection was 94.2%, and freedom from reoperation 83.6%. Biological valve and younger age were significant adverse parameters for freedom from reoperation (p = 0.01 and p = 0.01). There have been 21 late deaths, 15 due to cardiac causes. Kaplan-Meier survival, including operative mortality, at five and ten years was 77.4% and 68.0%, respectively. On Cox proportional hazards regression, Staphylococcus aureus infection (p = 0.008) and older age (p = 0.04) were independent adverse predictors of survival. CONCLUSION: AVR for endocarditis carries a relatively high operative mortality, but can result in a satisfactory freedom from recurrent infection, reoperation and long-term survival. Analysis of our series demonstrates that implantation of a biological valve limits the freedom from reoperation and that infection by Staph. aureus reduces the probability of long-term survival.

Mid-term results with 1,503 CarboMedics mechanical valve implants.

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was introduced in 1986, and first implanted by the authors in March 1991. The aim of this study was to analyze the authors' clinical experience with this valve. METHODS: Between March 1991 and October 1998, 1,503 valves were implanted in 1,350 patients (758 males, 592 female; mean age 62 +/- 13 years). Follow up was 99% complete and totaled 4,342 patient-years (pt-yr). RESULTS: The hospital mortality rate was 4.3% (59/1,350). Preoperative NYHA class (p = 0.012), emergency surgery (p = 0.03) and cardiopulmonary bypass time (p = 0.01) were significantly associated with increased risk of operative death (multiple logistic regression). Mean (+/- SEM) survival rates at one and five years were 92.0 +/- 0.7% (n = 1,109) and 80.0 +/- 1.3% (n = 335). Freedom from valve-related complications (linearized rate 5.6%/pt-yr) at one and five years was 89.5 +/- 0.8% (n = 1,031) and 76.3 +/- 1.4% (n = 284). Linearized rates for bleeding events were 2.19%/pt-yr, thromboembolic events 2%/pt-yr, operated valvular endocarditis 0.18%/pt-yr, valve thrombosis 0.14%/pt-yr and non-structural dysfunction 1.22%/pt-yr. Freedom from reoperation at one and five years was 98.5 +/- 0.3% (n = 1,107) and 97.3 +/- 0.5% (n = 334). CONCLUSION: Mid-term results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.

Tricuspid valve replacement: bioprostheses are preferable.

BACKGROUND AND AIM OF THE STUDY: Tricuspid valve replacement (TVR) is rarely undertaken, most surgeons preferring to use conservative tricuspid valve procedures. Thus, limited data are available in patients following TVR. The purpose of this study was to analyze the early and late results in 87 patients (52 tissue valves, 35 mechanical prostheses) who underwent TVR between January 1973 and September 1996. METHODS: The patient group comprised 74 (85%) females and 13 (15%) males; mean (+/- SD) age was 59.4 +/- 12.8 years; range: 15 to 81 years). Forty-four patients (51%) had undergone at least one previous cardiac operation. There were 19 (23%) isolated TVRs, 43 (49%) triple valve replacements, and 25 (29%) double valve replacements. Total cumulative follow up was 707 patient-years (pt-yr) (tissue valves 393 pt-yr, mechanical valves 314 pt-yr); mean follow up was 8.1 years (range: 0 to 23.6 years). RESULTS: The early (30-day) mortality rate was 10.3% (n = 9; tissue 7, mechanical 2, p = 0.28). Logistic regression identified prolonged cardiopulmonary bypass time (p <0.03) and advanced NYHA functional class (p <0.007) as risk factors for operative death. No risk factors were significant on multiple logistic regression analysis. Mean (+/- SEM) survival rate was 68 +/-5.3% (n = 50) at 5 years, 52 +/- 5.9% (n = 36) at 10 years, 35 +/- 6% (n = 20) at 15 years, and 16 +/- 5.3% (n = 7) at 20 years. Freedom from tricuspid valve reoperation at 5, 10 and 15 years was 93 +/- 3.3% (n = 46), 83 +/- 5.8% (n = 33) and 71 +/- 2.8% (n = 17) respectively. Eleven patients required tricuspid valve reoperation: six mechanical valves (five for prosthetic valve thrombosis and one for mechanical failure secondary to pannus ingrowth), and five tissue valves (two for prosthetic valve endocarditis and three for prosthetic valve degeneration). Freedom from reoperation at 5, 10 and 15 years for tissue prostheses was 97 +/- 2.5%, 89 +/- 6.3% and it was 70 +/- 12%, and 86 +/- 7.4%, 74 +/- 9.9% and 68 +/-11% for mechanical prostheses. The mechanical prostheses required reoperation earlier after the initial surgery. CONCLUSIONS: We recommend the use of a bioprosthesis in the tricuspid position because of its initial durability and low reoperation rate.

Novel application of vacuum assisted closure technique to the treatment of sternotomy wound infection.

Infection of the sternotomy wound is a potentially devastating and sometimes lethal complication following cardiac surgery. Established treatment may involve a combination of debridement, packing, delayed closure, plastic reconstruction, re-wiring and irrigation dependent on the severity of infection. Vacuum assisted closure, originally adopted for the treatment of non-healing wounds, has recently gained popularity among various surgical specialities in managing complex wound infection. Here we describe this novel technique of managing postoperative sternal wound infection.

Complex and extensive infective endocarditis: a novel surgical approach.

Endocarditis involving the central fibrous body of the heart requires carefully planned surgical intervention. We present a novel approach in a 65-year-old male with extensive endocarditis involving the aortic root, ventricular septum, central fibrous body together with mitral, aortic and tricuspid valves.

A prospective randomized study to evaluate the renoprotective action of beating heart coronary surgery in low risk patients.

OBJECTIVES: Cardiopulmonary bypass (CPB) is widely regarded as an important contributor to renal failure, a well recognized complication following coronary artery surgery (coronary artery bypass grafting (CABG)). Anecdotally off-pump coronary surgery (OPCAB) is considered renoprotective. We examine the extent of renal glomerular and tubular injury in low-risk patients undergoing either OPCAB or on-pump coronary artery bypass (ONCAB). METHODS: Forty low-risk patients with normal preoperative cardiac and renal functions awaiting elective CABG were prospectively randomized into those undergoing OPCAB (n=20) and ONCAB (n=20). Glomerular and tubular injury were measured respectively by urinary excretion of microalbumin and retinol binding protein (RBP) indexed to creatinine (Cr). Daily measurements were taken from admission to postoperative day 5. Fluid balance, serum Cr and blood urea were also monitored. RESULTS: No mortality or renal complication were observed. Both groups had similar demographic makeup, Parsonnet score, functional status and extent of coronary revascularization (2.1+/-1.0 vs. 2.5+/-0.7 grafts; P=0.08). Serum Cr and blood urea remained normal in both groups throughout the study. A significant and similar rise in urinary RBP:Cr occurred in both groups peaking on day 1 (3183+/-2534 vs. 4035+/-4079; P=0.43) before reapproximating baseline levels. These trends were also observed with urinary microalbumin:Cr (5.05+/-2.66 vs. 6.77+/-5.76; P=0.22). Group B patients had a significantly more negative fluid balance on postoperative day 2 (-183+/-1118 vs. 637+/-847 ml; P=0.03). CONCLUSIONS: Although renal complication or serum markers of kidney dysfunction were absent, sensitive indicators revealed significant and similar injury to renal tubules and glomeruli following either OPCAB or ONCAB. These results suggest that avoidance of CPB does not offer additional renoprotection to patients at low risk of perioperative renal insult during CABG.