Postoperative Hemodialysis Research Articles

Effect of Off-Pump and On-Pump Coronary Artery Bypass Grafting on Renal Function

Background. Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) has the risk of renal dysfunction. The cause of renal dysfunction after CPB is multifactorial, such as nonpulsatile flow, renal hypoperfusion, hypothermia, and duration of CPB. This study compared off-pump technique with on-pump technique on renal function in patients who underwent CABG. Methods. Sixty patients with normal preoperative renal functions undergoing CABG were randomly assigned to conventional revascularization with CPB (on-pump) or beating heart revascularization (off-pump). Renal functions were assessed up to 10 days postoperatively. Results. Creatinine clearance was found to be significantly higher in the off-pump group than in the on-pump group (p < .05). The off-pump group had significantly less increase in creatinine levels when compared with the on-pump group (p < .05). The free water clearance values decreased similarly in both groups; however, the recovery was more prompt in the off-pump group (p < .05). No significant differences were found in the prevalence of postoperative hemodialysis. Conclusion. The off-pump technique may provide a positive contribution and sufficient protection on postoperative renal functions in patients undergoing CABG.

Anesthésie–réanimation d’un patient en ischémie aiguë des membres inférieurs

To appreciate the severity of a patient with acute limb ischaemia, to know how to manage these patients during the perioperative period. References were obtained from PubMed data bank (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) using the following keywords: acute limb, ischaemia, prognosis, complications, rhabdomyolysis, hyperkalaemia, compartment syndrome, fasciotomy. Ischaemia of the lower limbs is a medico-surgical emergency. The ischaemia implies a decrease of cellular energetic stocks and an increase in intracellular calcium. During reperfusion, the calcium paradox is exacerbated and ROS formation produces membrane damage. Tissue oedema and a local and general inflammatory syndrome occur. Clinical symptoms of acute ischaemia include pallor, pulselessness, decrease of temperature and pain. Occurrence of neurological symptoms is a sign of severity. Prognosis of patients relates directly to preexisting collateral circulation, aetiology of the occlusion (thrombosis vs embolus), duration of ischaemia, topography of the occlusion (severity of proximal occlusions as the acute aortic occlusion), and co-morbidity (renal failure, heart failure). The temperature of the ischaemic limb, quality of the downstream circulation, extension of the thrombus, arterial pressure and association to a venous thrombosis are other prognostic factors of lower limb ischaemia. The first treatment to be initiated is high doses of heparin. Once the diagnosis is made, the number of preoperative tests will be as small as possible because of the urgency of revascularization. Arteriography will be performed only when really needed and when its realization will not delay revascularization and will not alter the patient's prognosis. Where general anesthesia is required, the choice of anaesthetic agents will be based on their haemodynamic stability. During severe acute limb ischaemia, monitoring of invasive pressure is recommended, as well as regular dosages of potassium, arterial gases and CPK. Preoperatively in case of severe ischaemia, (proximal occlusion lasting more than 6 hours), preventive treatment, including controlled reperfusion with heparinized serum is indicated. Surveillance and prevention of a rhabdomyolysis and renal failure are imperative. Immediately after reperfusion, a dosage of potassium must be performed; moreover that hyperkalaemia is favoured by acidosis or renal failure. Postoperative haemodialysis is performed in case of hyperkalaemia or renal failure. Occurrence of compartment syndrome has to be checked and fasciotomy must be performed in case of a doubt on the microcirculation integrity.

Introduction of adjuncts and their influence on changing results in 402 consecutive thoracoabdominal aortic aneurysm repairs.

To assess the influence of adjuncts, cerebrospinal fluid drainage (CSFD) and evoked potentials, on morbidity and mortality after thoracoabdominal aortic aneurysm (TAAA) repair and to update our experience. Between February 1981 and February 2003, 402 consecutive patients underwent repair of their TAAA using simple cross-clamping between 1981 and 1994 (n = 123; CC), left heart bypass (from 1987; n = 254) or extracorporeal circulation (n = 25; ADJ). Somatosensory evoked potentials were used in 264 patients and motor evoked potentials in 176 patients. CSFD was used in 202 patients (50.2%). Overall hospital mortality was 10.9:14.1% in the CC-group versus 9.1% in the ADJ-group (P = 0.07). The incidence of postoperative dialysis was 6.1%. Paraplegia and paraparesis together was found in 11.3%. Independent risk factors for hospital mortality were age (OR 1.1 per year, 95% CI 1.04-1.16), rupture (OR 3.8, 95% CI 1.7-8.8) and postoperative hemodialysis (OR 8.1, 95% CI 3.2-20.3). For postoperative hemodialysis the risk factors were age >/=75 years (OR 3.2, 95% CI 1.1-9.7), a preoperative creatinine level higher than 150 microM/l (OR 6.5, 95% CI 2.6-16.2), and as a protective factor operation performed after 1995 (OR 0.2, 95% CI 0.06-0.6). For spinal cord dysfunction (paraplegia and paraparesis together) the protective factors were age >/=75 years (OR 0.16, 95% CI 0.02-1.2), operation performed after 1995 (OR 0.31, 95% CI 0.15-0.65) and a previous aortic dissection (OR 0.38, 95% CI 0.15-0.9). The use of different adjuncts introduced over the years clearly influenced our results in a positive way.

Outcome and complications of intraoperative hemodialysis during cardiopulmonary bypass with potassium-rich cardioplegia

Background:Potassium-rich cardioplegia has advantages over other cardioplegic solutions in preserving the myocardium during cardiopulmonary bypass, but it is avoided in patients with renal failure because of hyperkalemia. Methods:We first determined the ability of intraoperative hemodialysis (IHD) to remove potassium during cardiopulmonary bypass with potassium-rich cardioplegia in 9 patients by measuring potassium levels in all dialysate and urine. We then studied 24 patients with renal failure, grouped with the 9 previous patients, to assess safety, rebound hyperkalemia, and patient outcome with this technique. Results:In the first phase, 9 patients were administered 128 ± 11 mmol of potassium in potassium-rich cardioplegia, and IHD removed 157 ± 23 mmol. Urinary potassium excretion was only 10 ± 3 mmol. Potassium removal occurred at a rate of 1.25 mmol/min with 0-mEq/L (mmol/L) potassium dialysate and a rate of 0.75 mmol/min with 3.0-mEq/L (mmol/L) potassium dialysate. In all 33 patients, successful initiation of cardiac rhythm occurred after cardiopulmonary bypass, and 5 patients had cardiac arrhythmias possibly from hypokalemia. In the next 24 hours, 5 dialysis-dependent patients developed hyperkalemia (potassium > 5.2 mEq/L [mmol/L]) requiring hemodialysis. Postoperative hemodialysis was delayed 2 to 3 days in the other patients. The overall death rate was 24% at 30 days. Conclusion:IHD effectively and safely removes potassium administered during potassium-rich cardioplegia during cardiopulmonary bypass in patients with renal failure and prevents postoperative hyperkalemia in the majority of patients. Overall mortality in patients with acute and chronic renal failure undergoing cardiac surgery is high irrespective of control of potassium balance in these patients.

Insertion of Short Introducer Sheaths into a Polyurethane Vascular Access Graft for Immediate Hemodialysis Access

While native AV fistulae are considered the 'gold standard' for hemodialysis patients in need of long-term access, synthetic grafts are the best option for patients who are not candidates for an AV fistula. While AV fistulae should be allowed to mature for 3 - 4 months prior to cannulation, PTFE grafts may be cannulated 14 days after placement. Despite the benefit of earlier cannulation in PTFE graft recipients compared to AV fistulae patients, one critical limitation is that immediate post-operative cannulation is not possible. The self-sealing nature of the polyurethane Vectra(R) Graft overcomes the time restriction until first cannulation, allowing much earlier vascular access than conventional PTFE grafts. We describe here a procedure for insertion of 5-French DialEasetrade mark Introducer Sheaths into the Vectra Graft for immediate, post-operative hemodialysis access. This procedure eliminates time restrictions until first cannulation of the Vectra Graft; the sheath's large diameter sideport ensures high flow for efficient hemodialysis. Moreover, insertion of the sheath into a new or existing Vectra Graft provides vascular access for inspection of the graft anastomoses, angiography, angioplasty, venography, and declotting procedures. The post-operative introduction of DialEase Sheaths into a Vectra Graft for immediate hemodialysis was successfully performed in 35 patients. All patients then immediately received high-flow hemodialysis (400 - 500 ml) with venous pressures < 125 mmHg and negative arterial pressure ~100 mmHg. To date, there have been no infections, immediate graft thrombosis or other complications associated with this procedure, and all patients have remained free of anastomotic problems. (The Journal of Vascular Access 2003; 4: 62-7).

Surgical outcome of abdominal aortic aneurysm repair in patients undergoing chronic hemodialysis.

Abdominal aortic aneurysm repair in patients undergoing chronic hemodialysis presents several surgical difficulties due to tissue fragility, accelerated atherosclerosis, and calcification of the aorta. In addition to these surgical procedure-related problems, anemia, electrolyte abnormalities, bleeding tendency, and susceptibility to infection were also critical issues in perioperative management. The aim of this study was to examine the surgical outcome of abdominal aortic aneurysm repair in patients undergoing chronic hemodialysis. Between January 1988 and August 2001, six patients undergoing chronic hemodialysis underwent repair of an abdominal aortic aneurysm. There were five males and one female, and the mean age was 65 years. Two of the six patients had bilateral common iliac artery aneurysms in addition to the abdominal aortic aneurysm. At the time of abdominal aortic aneurysm repair, the duration of hemodialysis had ranged from 3 to 109 months, with a mean of 34 months. All patients underwent hemodialysis on the day prior to the abdominal aortic aneurysm repair operation. The first postoperative hemodialysis was scheduled to be performed on the day after operation or later. The mean duration of operation was 291 min. Blood transfusion was required in all patients. The first postoperative hemodialysis was performed between the first and third postoperative days. Postoperative complications were: ileus in one, and atrial fibrillation and blue toe syndrome just after operation in one. There was no hospital death. The follow-up period was 56 months. One patient died of lingual cancer at 102 months after operation. Five patients are alive. Abdominal aortic aneurysm repair can be done in patients on chronic hemodialysis with an acceptable early and long-term outcome.

Nosocomial infections in left ventricular assist device recipients.

Infection remains a serious complication of left ventricular assist device (LVAD) implantation. We performed a cohort study to assess infections among patients who underwent LVAD implantation from October 1996 through May 1999. Thirty-six LVADs were implanted in 35 patients; the mean duration (+/- standard deviation) of LVAD use was 73+/-60 days (total for all patients, 2565 days). Sixteen patients developed surgical site infections (SSIs; rate, 6.2 infections per 1000 LVAD days); 9 were deep-tissue or organ/space infections and 7 were superficial. Other infections included 7 cases of pneumonia (rate, 2.7 cases per 1000 LVAD days), 6 venous infections (rate, 2.3 per 1000 LVAD days), 2 bloodstream infections (rate, cases 0.8 per 1000 LVAD days), 3 urinary tract infections, and 2 skin and soft-tissue infections. Deep SSIs were associated with the requirement for postoperative hemodialysis (P=.02). Overall use of antibiotics was extensive, and a trend toward infection with antibiotic-resistant organisms was noted. Infections were a frequent complication of LVAD implantation. Further studies of interventions for preventing infection in LVAD recipients are warranted.

Immunosuppression for delayed or slow graft function in primary cadaveric renal transplantation: use of low dose tacrolimus therapy with post-operative administration of anti-CD25 monoclonal antibody.

Patients who develop delayed graft function (DGF) following cadaveric renal transplantation have inferior survival to those who do not. Calcineurin inhibitors (CNI) may prolong recovery from DGF. Patients with DGF are therefore routinely treated with either polyclonal antilymphocyte preparations or monoclonal anti-CD3 monoclonal antibodies and delayed introduction of CNI. The purpose of this study was to evaluate the efficacy of the anti-CD25 monoclonal antibody basiliximab (BSLIX) started post-operatively in patients at high risk for DGF combined with low dose tacrolimus (TAC). Patients who received a primary cadaveric renal transplant only after August 1998 were included in this retrospective study (n = 143). All patients received TAC and mycophenolate Mofetil (MMF) pre-operatively. At 6 h post-operatively, graft function was assessed clinically by urine output and serum creatinine. Those patients who had a urine output < 300 cc/6 h or a rising serum creatinine were presumed to be at risk for DGF (n = 46). These patients were treated with 20 mg BSLIX and had TAC dose reduced to maintain a trough blood level of < 5 ng/mL. Basiliximab was repeated at day 5. Patients not felt to be at risk for DGF were treated with standard TAC dose with trough level target of 9-12 ng/mL. Patients at risk were classified as DGF if they needed dialysis or as slow graft function (SGF) if they did not. The combined group (SGF/DGF) were analysed together. Patients with SGF/DGF had their TAC dose increased to achieve trough levels of 9-12 ng/mL when renal function improved. Patient groups were compared for demographics, need for dialysis, serum creatinine, glomerular filtration rate (GFR), TAC trough levels, MMF dosage, complications and 1- and 2-yr actuarial graft survival. Patients with SGF/DGF had a longer length of stay (8 vs. 5.7 d), were more likely to be black (41.3 vs. 25.7%), and required more post-operative haemodialysis (HD) (52.2 vs. 4.1%). SGF/DGF and non-SGF/DGF patients had similar rates of rejection (28.2 vs. 19.6%, p = 0.28) and steroid resistant rejection (SRR) (6.5 vs. 2.1%, p = 0.32). There were no differences in the rate of cytomegalovirus (CMV) infection (4.3 vs. 6.1%). Serum creatinine was higher and GFR lower at all time points in the SGF/DGF patients. The 1 and 2 yr actuarial survival in the non-SGF/DGF patients was 97.6 and 97.6% compared with 1 and 2 yrs actuarial survival of 94.1% and 80.0% in the SGF/DGF patients, p = 0.04. There were no differences in patient survival. There were no differences in actuarial survival for the SGF/DGF patients who received dialysis compared with those who did not receive dialysis. Comparison of patients who received HD (n = 28) to those who did not (n = 115), regardless of group demonstrated no difference in 1 and 2 yrs actuarial survival, 100 and 94.1% in HD patients vs. 98.2 and 92.5% in non-HD patients. The clinical diagnosis of SGF/DGF can be made 6 h post-operatively based on urine output and serum creatinine. Basiliximab can be started post-operatively in these patients and decreased levels of TAC can be used to achieve acceptably low rates of rejection in these patients. However, SGF/DGF patients, regardless of their need for dialysis, have worse function at 1 yr and lower 2-yr actuarial graft survival compared with non-SGF/DGF patients. Most of the poor survival can be attributed to the SGF group. Further strategies to either prevent SGF/DGF or to optimize treatment in these patients are needed.

SURGICAL OUTCOME OF THE CARDIOVASCULAR SURGERY IN PATIENTS WITH CHRONIC HEMODIALYSIS

PURPOSE Cardiovascular surgery in patients with chronic hemodialysis(HD) presents several difficulties due to accelerated atherosclerosis and calcified aorta in addition to anemia or bleeding tendency. The purpose of this paper is to clarify the surgical outcome of the cardiovascular surgery in patients with HD. PATIENTS Between 1991 and 2001, 10 patients with HD underwent cardiovasculdr surgery. Preoperative diagnoses were abdominal aortic aneurysm(AAA) in 6, ischemic heart disease(IHD) in 2, mitral regurgitation(MR) in 1, and aortic regurgitation(AR) in 1. Nine patients revealed the preoperative anemia and received erythropoietin. The mean duration of HD was 61.1 months at the time of operation. All patients underwent HD on the day before operation. RESULTS In the AAA repair, the straight graft was used in 2 and the bifurcated graft in 4. Off pump CABC was performed in 2 with IHD. Mitral valve plasty(MVP) and aortic valve replacement were performed in patients with MR and AR, respectively. Blood transfusion was required in all patients. Intratracheal tube was removed within 24 hours after operation in all patients. Postoperative HD was started between the first and the third postoperative days in 9 patients. One patient underwent peritoneal dialysis intraoperatively. There was no hospital death. During follow-up period, eight patients were alive and two patients died of lingual cancer and intracerebral bleeding. CONCLUSION Cardiovascular surgery can he done in patients on chronic HD with acceptable early and long-term outcome.

Long term results of liver-kidney transplantation in children with primary hyperoxaluria

From 1990 to 2000, we performed eight liver-kidney transplants in eight children, aged 1-16 years, with end-stage renal failure (ESRF) due to primary hyperoxaluria (PH1). The duration of dialysis before transplantation ranged from 2 to 42 months (mean 14 months) and was <1 year in four patients. Only the first patient underwent postoperative hemodialysis; in the other five, we chose to induce maximal diuresis from the first hours with intravenous and intragastric hyperhydration (> or =3 l/m2 per day). High water intake with nocturnal tube hydration was maintained for 6 months to 5 years, as long as oxaluria exceeded 0.5 mmol/day. A quadruple sequential immunosuppressive regimen was used. Two patients died during liver graft surgery. The other six patients are alive and well, with a mean follow-up of 7.4 years (range 5-11 years). Patient and graft survival is 75% at 5 years. At latest follow-up, liver tests were normal in all six patients; creatinine clearance ranged from 55 to 95 ml/min per 1.73 m2 (mean=74). Oxaluria was lower than 0.4 mmol/day in all patients (mean=0.22). The six patients underwent 15 renal biopsies, 1-11 years after transplantation. Chronic transplant nephropathy was present in four patients and mild cyclosporin nephrotoxicity in another. No oxalate crystals were seen and repeat ultrasonography has been consistently normal in all patients. The three patients with bone oxalosis showed progressive complete healing of bone lesions. All six children or adolescents now live a normal life. From this series, we conclude that early combined liver-kidney transplantation is the treatment of choice for children with ESRF due to primary hyperoxaluria.

Suprahepatic venacavaplasty (cavaplasty) with retrohepatic cava extension in liver transplantation: experience with first 115 cases.

We first introduced the orthotopic liver transplantation utilizing cavaplasty technique in 1994. This paper describes the surgical technique and assesses the outcome of the cavaplasty OLT. The cavaplasty procedure was used in 115 consecutive orthotopic liver transplantations, including six left lateral and two right lobe transplantations, between November 1994 and September 2000. Fifty-three (66.3%) transplantations required femoro-axillary veno-venous bypass in the initial 4 years, whereas only eight (22.9%) needed VB in the subsequent 2 years. Conversion to piggyback or standard technique was not necessary in any patient. Median results are as follows: operative time 4.5 hr, warm ischemia time 25 min, and blood transfused (packed red blood cells) 6 units. These findings did not differ between first transplantation and retransplantation. There were no perioperative deaths related to the cavaplasty technique. No hepatic venous outflow obstruction was observed, including living-related OLTs. No patient required postoperative hemodialysis for acute renal failure. The median intensive care and hospital stays were 2 days and 10 days, respectively. The cavaplasty technique requires no retrocaval, hepatic vein, or short hepatic vein dissection, and the inferior vena cava can be preserved, which provides advantages for hepatectomy and easy hemostasis, especially during retransplantation. The wide-open triangular caval anastomosis is easy to perform, allowing short implantation time and size matching and avoiding outflow obstruction. The short implantation time reduces the need for veno-venous bypass. Our experience indicates that the cavaplasty technique can be applied to all patients and is justified by minimal technical complications.

Positive effect of low molecular weight dextrans on the early graft function.

This study evaluates the effect of the low molecular weight dextrans as a perfusion solution on early graft function of twenty living donor kidneys. Ten kidneys were perfused with +4 degrees C Ringer lactate after nephrectomy while other ten with +4 degrees C Ringer lactate + 10% Dextran. Immediate and delayed kidney function, blood creatinine, postoperative hemodialysis requirement, Doppler US and renal scintigraphy, third month graft survival and number of removed grafts were examined postoperatively as well as kidney biopsies. No statistical difference was found between the groups regarding the post-transplant ATN period. But the microscopic examinations demonstrated less damage-more function in Ringer lactate+Dextran group compared to Ringer lactate alone.

Cardiac surgery with cardiopulmonary bypass in patients with chronic renal failure

Objective: Renal failure is known to increase the morbidity and mortality in patients undergoing cardiac surgery. The results of heart surgery in patients with non–dialysis-dependent, mild renal insufficiency are not clear. Methods: One hundred nineteen adult patients with chronic renal failure underwent cardiac surgery. Group I consisted of 93 patients who had creatinine levels between 1.6 and 2.5 mg/dL but who were not supported by dialysis. Group II consisted of 18 patients with creatinine levels higher than 2.5 mg/dL who were not supported by dialysis. Group III consisted of 8 patients with end-stage renal disease who were receiving hemodialysis. Results: The hospital mortality rates were 11.8%, 33.0%, and 12.5%, respectively. Morbidity was 21.5%, 44.4%, and 75.0%, respectively, in groups I, II, and III. Postoperative hemodialysis was needed in 2 (2.15%) patients from group I and 6 (33%) patients from group II. On multivariable logistic regression analysis, risk factors for mortality were preoperative creatinine level more than 2.5 mg/dL, angina class III-IV, emergency operation, excessive mediastinal hemorrhage, postoperative pulmonary insufficiency, low cardiac output, and rhythm disturbances. Risk factors for morbidity were preoperative creatinine level more than 2.5 mg/dL and postoperative dialysis. Conclusions: Chronic renal failure increases the mortality and morbidity in patients undergoing cardiac surgery. Renal insufficiency with creatinine levels higher than 2.5 mg/dL increases the risk of postoperative dialysis and prolongs the length of hospital stay. Careful preoperative management and intraoperative techniques, such as avoiding low perfusion pressure and using low-dose dopamine, may be useful for a good operative outcome. (J Thorac Cardiovasc Surg 1999;118:306-15)

USEFULNESS OF CONTINUOUS HYPOTERMIC PERFUSION PRESERVATION FOR CADAVERIC RENAL HIGH RISK GRAFTS

159 〈AIM〉 Because of the severe shortage of donors for cadaveric renal transplantation (Tx) in Japan, cadaveric renal grafts are being used for Tx even when they are high risk grefts (HRG). We always use continuous hypothermic perfusion preservation (CP) to evaluate whether HRG should be used for Tx and to improve the function of HRG. The aim of this study is to assess the usefulness of CP for Tx of cadaveric renal HRG, so-called non-heart-beating donors (NHBD). 〈METHODS〉 Of the 125 kidneys preserved by CP at our center from March 1981 to April 1998, 92 kidneys met the study criteria. 50 of 92 kidneys were in poor condition, the study criteria were defined as follows: Group 1:23 kidneys with a long warm ischemic time (WIT) of 60 minutes or more; Group 2:13 kidneys procured with donor serum creatinine levels of 3.0mg/dl or more; Group 3:14 kidneys preserved by CP following simple cold storage (CS) in Euro-Collins solution for at least 40 hours. And comparison of CP with CS of 16 pairs of kidneys procured from NHBD. 〈RESULTS〉 All of 85 grafts with a good perfusion flow rate of more than 0.4ml/min/g (1.10 ± 0.53 ml/min/g) and without a rise in perfusion pressure showed the good kidney functions after Tx. The remaining 7 grafts showed a poor perfusion flow rate of 0.4 ml/min/g or less (0.29 ± 0.04 ml/min/g, vs good, p<.001) and a rise in perfusion pressure. These grafts were determined as poor viability and discarded. They were histologically confirmed as unacceptable grafts for Tx. 4 of the contralateral kidneys procured from the same donors were transplanted at another center, all grafts resulted in primary non-function. When comparing preservation methods despite the longer total ischemic time in CS (7.8 hours in CS vs 11.7 hours in CP), CP achieved a higher incidence of immediate function (IF) 9 cases, a shorter period of postoperative hemodialysis days (HD) in 8 cases, and better graft survival in 3 cases when compared with CS from the same NHBD. In these study, CP achieved a higher incidence of IF, and a shorter period of HD. 〈CONCLUSION〉 We found CP is to be useful both for improving of HRG and for assessing HRG viability.

Supraceliac Aortic Occlusion: A Safe Approach to Pararenal Aortic Aneurysms

Twenty-four patients who underwent surgery for pararenal aortic aneurysms between January 1992 and April 1997 are reviewed. Eighteen patients had primary atherosclerotic aneurysms, three patients had symptomatic infected aneurysms, two patients had an aneurysm proximal to a prior aortic repair, and one patient had a pseudoaneurysm of a proximal aortic graft anastomosis. Thirteen patients underwent elective operation, five had an urgent operation, and six patients underwent an emergency procedure. Five patients had the proximal aortic clamp placed between the renal arteries (Group I), three patients had it placed between the superior mesenteric and the renal arteries (Group II), and 16 patients had it placed in a supraceliac location (Group III). Aneurysm size, age, sex, preoperative blood chemistries (including hemoglobin, hematocrit, liver function studies, and coagulation studies) were similar in all groups. Two patients in Group III were on hemodialysis preoperatively. Preoperative renal function (blood urea nitrogen and creatinine) was the same in all groups. Visceral ischemic time was 43.4 +/- 9.37 min to the distal kidney in Group I, 26.6 +/- 7.63 min in Group II, and 24.5 +/- 6.22 min in Group III. Mean transfusion requirements were similar in all groups. Two patients in Group I required postoperative hemodialysis. No patient in either Group II or III developed renal insufficiency. Mortality was the same in each group but was related to the urgency of operation (elective 7.6%, urgent 40%, emergent 50%). Intrarenal clamping (Group I) was associated with more renal and gastrointestinal complications than either suprarenal or supraceliac clamping. Although suprarenal and supraceliac clamping had similar results, our preference is supraceliac clamping because it is technically easy to achieve and is associated with few end-organ complications.

Predictors of Hospital Mortality in Type A Aortic Dissections: A Retrospective Analysis of 148 Consecutive Surgical Patients

Reports in the literature frequently concern miscellaneous types of dissections. This makes correct interpretation of data difficult. In order to assess the determinants of hospital mortality, the results of 148 consecutive patients over a 23-year period, all operated on for a type A dissection, were reviewed. Mean(s.d.) age was 56(13.1) years, 64% were male. An acute dissection (surgery within 14 days after onset of symptoms) was performed in 139 patients. Stigmata of the Marfan syndrome were present in 6.1% ( n = 9). Peripheral vascular ischaemic complications were observed in 27.7%. Nowadays, diagnosis is primarily confirmed using transoesophageal echocardiography (75 correct diagnoses among 76 performed). Operation consisted of repair or replacement of the ascending aorta. Resuspension of the aortic valve was performed in 74 patients, and arch replacement in 25. In 74 patients, distal repair was done under deep hypothermic circulatory arrest. Hospital mortality rate was 23.6% (35 patients), though mortality rate calculated over the period 1990–1993 was 17.4% (P= n.s.). Univariate analysis revealed the following variables to be statistically significant predictors of hospital mortality ( P &lt; 0.05): preoperative ischaemic complications, preoperative resuscitation, haemopericardium, postoperative neurological complications, rethoracotomy, renal insufficiency and intestinal ischaemia. Multivariate stepwise logistic regression indicated preoperative resuscitation, postoperative haemodialysis and postoperative neurological complications as the only independent predictors of hospital death. Dissections arising from a primary intimal tear in the descending aorta had a more favourable outcome ( P = 0.06, odds ratio 0.1). Although hospital mortality has declined over the past few years, no decline was seen in operative mortality since gelatine-resourcine-formol (GRF) glue is used as a routine. Transoesophageal echocardiography is the first choice in confirming diagnosis. Early operation is advocated, with careful haemostasis, before the development of cardiac tamponade or end-organ ischaemia, as the cornerstone of a successful treatment of a type A dissection. Reduction of neurological complications will further improve the results.

Postoperative Complications Following Hemodialysis Access Procedures

From July 1986 to September 1996, 322 arteriovenous fistulas were constructed in 250 patient for permanent hemodialysis: 315 autogenous and 7 graft fistulas (polytetraflouroethylen (PTFE)-4, dacron-3). 269 snuffbox (84%), 29 radiocephalic (8%), 24 brachiocephalic (7%) and 1 subclavian (0.3%) arteriovenous fistulas were performed. Successfull rate at first operations (255/322) was 79%. In the immediate postoperative period, 54 snuff box fistulas (20%) developed complications (52 early occlusion and 2 postoperative local bleeding) while 6 radiocephalic fistulas (20.6%) developed immediate postoperative complications (5 early occlusion and 1 anastomotic hemorrhage). Brachiocephalic fistulas didn't developed any immediate postoperative complications. In the long-term period 9 brachiocephalic fistulas (37.5%) developed complications (4 venous return dysfunction 3 aneurysm 1 graft infection and 1 late trombosis) while 4 snuff box fistulas and 1 radiocephalic fistulas developed late trombosis. Based on this complication rates, we should make every effort to construct tire autogenous snuff box fistula as the first choice of hemodialysis access procedure in properly selected patients. Hemodiyaliz Amacli Arteriovenoz Fistul Uygulamalarinda Ameliyat Sonrasi Gelisen Komplikasyonlar Haziran 1986-Eylul 1996 yillari arasinda kronik bobrek yetmezligi olan 250 hastaya hemodiyaliz amacli toplam 322 arteriovenoz fistul uygulamasi yapildi. 269 (%83.3) snuff box, 28 (%8,6) radiosefalik ve 24 (%7.4) brakiosefalik arteriovenoz fistul operasyonu gerceklestirildi. 7 hastaya sentetik greft uygulandi (PTFE-4, dakron-3). ilk operasyonda basari orani %79 (255/322) idi. Ameliyat sonrasi erken donem komplikasyon oranlan; snuff box fistul uygulananlarda %20 (52 erken tikaniklik, 2 lokal kanama) ve radiosefalik fistul uygulanlarda %21.4 (5 erken tikaniklik, 1 anastomoz bolgesinden kanama) idi. Brakiosefalik fistul uygulananlarda herhangi bir erken donem komplikasyonu gelismedi. 9 (%37.5) brakiosefalik fistul uygulamasinda gec donem komplikasyonu (4 venoz donus yetersizligi, 3 anevrizma formasyonu, 1 greft infeksiyonu ve 1 gec tromboz) gelisirken, 4 snuff box ve bir radiosefalik fistul uygulamasinda gec tromboz meydana geldi. Bu komplikasyon oranlan dikkate alindiginda, uygun hastalarda snuff box fistul uygulamasinin oncelikle tercih edilmesi gerektigi gorulmektedir.

Predictors of hospital mortality in type A aortic dissections: a retrospective analysis of 148 consecutive surgical patients

Reports in the literature frequently concern miscellaneous types of dissections. This makes correct interpretation of data difficult. In order to assess the determinants of hospital mortality, the results of 148 consecutive patients over a 23-year period, all operated on for a type A dissection, were reviewed. Mean(s.d.) age was 56(13.1) years, 64% were male. An acute dissection (surgery within 14 days after onset of symptoms) was performed in 139 patients. Stigmata of the Marfan syndrome were present in 6.1% ( n=9). Peripheral vascular ischaemic complications were observed in 27.7%. Nowadays, diagnosis is primarily confirmed using transoesophageal echocardiography (75 correct diagnoses among 76 performed). Operation consisted of repair or replacement of the ascending aorta. Resuspension of the aortic valve was performed in 74 patients, and arch replacement in 25. In 74 patients, distal repair was done under deep hypothermic circulatory arrest. Hospital mortality rate was 23.6% (35 patients), though mortality rate calculated over the period 1990-1993 was 17.4% ( P=n.s.). Univariate analysis revealed the following variables to be statistically significant predictors of hospital mortality ( P<0.05): preoperative ischaemic complications, preoperative resuscitation, haemopericardium, postoperative neurological complications, rethoracotomy, renal insufficiency and intestinal ischaemia. Multivariate stepwise logistic regression indicated preoperative resuscitation, postoperative haemodialysis and postoperative neurological complications as the only independent predictors of hospital death. Dissections arising from a primary intimal tear in the descending aorta had a more favourable outcome ( P=0.06, odds ratio 0.1). Although hospital mortality has declined over the past few years, no decline was seen in operative mortality since gelatine-resourcine-formol (GRF) glue is used as a routine. Transoesophageal echocardiography is the first choice in confirming diagnosis. Early operation is advocated, with careful haemostasis, before the development of cardiac tamponade or end-organ ischaemia, as the cornerstone of a successful treatment of a type A dissection. Reduction of neurological complications will further improve the results

Prophylactic use of low‐dose urodilatin for prevention of renal impairment following liver transplantation: a randomized placebo‐controlled study

Many therapeutic measures have been employed to prevent or at least ameliorate postoperative renal impairment following liver transplantation. Recent clinical phase II studies have demonstrated that the new natriuretic peptide urodilatin has beneficial effects on renal function following heart and liver transplantation. The present study reports the first prospective randomized placebo‐controlled trial of prophylactic urodilatin administration following liver transplantation.Seventy consecutive recipients of primary liver transplants were included in the study following randomization, and 33 patients continuously received urodilatin at a dose of 20 ng/kg/min for 7 d. The remaining 37 patients received a placebo infusion for the same time period. The course of serum creatinine and urea did not differ between the two groups nor did the daily urine production. However, the urodilatin group showed a higher preoperative median serum creatinine and a significant reduction on days 1 and 2, whereas this observation was not made in the placebo group. Furthermore, less furosemide was administered to the patients in the urodilatin group during the first 2 d. The incidence of postoperative hemodialysis and the number of treatments did not differ between the groups either (urodilatin group 4, vs. placebo group 6 and 22 for both groups, respectively). Side effects of the urodilatin therapy were not detected.The prophylactic low‐dose urodilatin administration resulted in a trend towards amelioration of the renal function, but did not result in significant differences between the two experimental groups. Further studies, using higher doses, will be required to define the value of urodilatin for prevention of renal impairment after liver transplantation.

Preoperative vancomycin prophylaxis decreases incidence of postoperative hemodialysis vascular access infections

The role of vancomycin in the treatment of infected arteriovenous chronic dialysis access is well established. However, the role of preoperative vancomycin administration in preventing infection in newly placed, revised, or surgically thrombectomized grafts has not been determiend. We performed a prospective randomized study to examine whether vancomycin prophylaxis can decrease the incidence of postoperative graft infections. Over a 5-year period, 206 patients undergoing 408 permanent vascular access procedures were randomized into two groups. Group 1 (206 procedures) received a single intravenous dose of 750 mg of vancomycin approximately 6 to 12 hours before vascular access placement procedures, while group 2 (202 procedures) did not. Patients were evaluated for access infection within the following 30 days and before use of the access for chronic dialysis. Access infection developed in two patients (1%) in group 1 and in 12 patients (6%) in group 2 (P = 0.006. All 14 infections occurred in upper extremity polytetrafluoroethylene grafts. We conclude that the use of preoperative single-dose intravenous vancomycin prophylaxis for hemodialysis vascular graft procedures reduces the risk of postoperative access infection.