Temporary Hemodialysis Research Articles

Azygos arch cannulation by central venous catheters for hemodialysis

Cannulation of central veins and placement of catheters for temporary haemodialysis is a common procedure in the management of patients with end stage renal failure. The internal jugular vein is the site of choice for central venous catheter placement, being associated with the lowest complication rate. This procedure can be associated with a variety of malpositions of the catheter and rarely, can lead to significant morbidity and even mortality, if this is not recognised and corrected early. For anatomical reasons, the risk of azygos arch cannulation is substantially increased if catheters are inserted via left-sided veins. We report a case with a rare complication associated with the insertion of a catheter for temporary haemodialysis.

Stpahylococcus aureus biofilms on central venous haemodialysis catheters

Biofilm bacterial infections are common in patients undergoing treatment with haemodialysis. This study involved 16 patients (7 males, 9 females; ages from 22 to 81 with an average age of 50) who had had a total of 25 temporary haemodialysis polyurethane catheter insertions into the subclavian vein (22 dual-lumen and 3 triple-lumen). The catheters remained in place from 3 to 91 days, on an average of 47 days. The reasons for catheter removal were: bad functioning (44%), suspicion of catheter-related infection (20%), availability of permanent access (16%), accidental removal (12%), signs and symptoms of infection at the site of catheter insertion (4%), and exogenous contamination (4%). Positive tip cultures were observed on seven of the catheters (28%), showing three positive blood cultures. The Staphylococcus aureus were identified in 12% of the blood cultures and isolated from one of the hubs, and biofilms were observed on all catheter tips. The S. aureus retrieved from both blood and catheters (tips and hubs) were resistant to penicillin and susceptible to azithromycin, ciprofloxacin, clindamycin, chloramphenicol, gentamicin, oxacillin, rifampin, sulfamethoxazole, tetracycline, and vancomycin. The S. aureus strains isolated from both blood and catheters (tips and hubs) were considered to be identical based on antibiotic susceptibility patterns and genetic similarity assessed using an automated ribotyping system.

Long-Term Renal Outcome of Autologous Stem Cell Transplantation in Light Chain Deposition Disease.

Light chain deposition disease (LCDD) is a systemic disorder characterized by deposition of nonamyloid monotypic light chains throughout the body. Renal dysfunction is a ubiquitous manifestation of the disease. Reports suggest that high-dose chemotherapy and autologous stem cell transplantation may be beneficial in the treatment of LCDD. However, the impact of autologous stem cell transplantation on renal function is unclear. This study retrospectively reviewed the effect of autologous stem cell transplantation on renal function in six patients with LCDD. Two patients had concurrent multiple myeloma, and one patient was on hemodialysis prior to transplantation. Patients received chemotherapy with dexamethasone alone or dexamethasone plus thalidomide prior to transplantation. Conditioning was performed with high-dose intravenous melphalan. All patients survived transplantation, but one sustained multi-organ failure shortly afterwards and died. Another patient required temporary hemodialysis following transplantation. All surviving patients achieved a hematologic response, although one ultimately relapsed and required further chemotherapy. Renal parameters also improved. On average, proteinuria levels decreased by 83% in four patients and increased by 1% in one patient. Creatine clearance calculated by the Modification of Diet in Renal Disease (MDRD) Study prediction equation improved by an average of 40%. This review suggests that autologous stem cell transplantation may be an effective therapy for renal dysfunction associated with LCDD.Clinical Characteristics of LCDD Patients at PresentationCharacteristicNumber or rangeMedianSex4 male, 2 femaleAge (years)35-6144Beta-2 microglobulin, μ/ml3.58-114.12Albumin, g/dl1.8-4.23.85Creatinine, mg/dl1.8-5.42.45MDRD*, ml/min12-5026.5Serum M protein, g/dl00Serum free light chains, mg/dl (n = 5)2.18-31219.624-hour urine protein, mg131-10,251679*Modification of Diet in Renal Disease Study prediction equation

Treatment of Refractory Pseudomonas Aeruginosa Exit-Site Infection by Simultaneous Removal and Reinsertion of Peritoneal Dialysis Catheter

Patients on continuous ambulatory peritoneal dialysis (CAPD) with Pseudomonas aeruginosa exit-site infection (ESI) refractory to antibiotic treatment often require replacement of their peritoneal dialysis catheter (PDC). The optimal interval between removal and reinsertion of the PDC is not known. There are relatively few data on the feasibility of simultaneous removal and reinsertion of dialysis catheters for the treatment of P. aeruginosa ESI. We retrospectively reviewed the short- and long-term outcomes of all CAPD patients who had undergone simultaneous removal and reinsertion of their PDC for the treatment of refractory P. aeruginosa ESI in our hospital between January 1994 and December 2003. During the operation, the old catheter was removed first and a new catheter was inserted into the opposite side of the abdomen. All patients received 7 days of antibiotic therapy postoperatively. CAPD was resumed after 2 weeks of intermittent peritoneal dialysis. Over a 10-year period, 37 CAPD patients underwent the operation. Mean age of the patients was 59.5 +/- 10.9 years. The interval between the diagnosis of ESI and the operation was 16.7 +/- 6.9 weeks. The patients received 7.6 +/- 2.5 weeks of antibiotic treatment before the procedure. Early postoperative complications were uncommon. None of the patients developed ESI within 4 weeks after the operation. At 1 year after the operation, 3 patients (8%) had developed recurrence of P. aeruginosa ESI 24 - 40 weeks postoperatively. Peritonitis due to P. aeruginosa was not observed. We conclude that simultaneous removal and reinsertion of the PDC is feasible in eradicating refractory ESI due to P. aeruginosa. This procedure alleviates the need for temporary hemodialysis and allows continuation of peritoneal dialysis.

Conversion of Temporary Hemodialysis Catheters to Permanent Hemodialysis Catheters: A Retrospective Study of Catheter Exchange versus Classic de novo Placement

Many clinicians believe that de novo access is required when converting temporary hemodialysis (HD) catheters to long-term or permanent catheters. However, since vascular access sites are at a premium in the dialysis patient, it is important to preserve existing central venous catheters and conserve future access sites. In this retrospective study, data from 94 patients referred to interventional radiology for placement of long-term, tunneled HD catheters between July 2001 and September 2002 were reviewed. The study group consisted of 42 patients in whom the temporary catheter was exchanged for a peel-away sheath and a tunneled catheter inserted using the existing venous access site. The control group included 52 patients who received traditional de novo placement of permanent catheters. Based on available follow-up data, we report a 100% technical success rate, with 72% patency at 30 days in the study group (n = 32; mean age 58 years). By comparison, de novo catheter placement (n = 35; mean age 59 years) yielded a 100% technical success rate, with 83% patency at 30 days. The overall infection rate was 0.30 per 100 catheter-days (total 3036 catheter-days) and 0.36 per 100 catheter-days (total 3295 catheter-days), respectively (chi2 = 0.64, p > or = 0.05). There was no incidence of exit site infection, tunnel infection, or florid sepsis in either group. Likewise, no stenosis or bleeding complication was noted. Thus conversion of a temporary HD catheter to a tunneled catheter using the same venous insertion site is safe, does not increase the risk of infection, and allows conservation of other central venous access sites.

Das pulmorenale Syndrom

Pulmonary-renal syndrome is a potentially life-threatening disorder, characterized by diffuse alveolar hemorrhage on the basis of pulmonary capillaritis in conjunction with rapidly progressive glomerulonephritis. Pulmonary-renal syndrome can originate from various systemic autoimmune diseases. ANCA-associated vasculitides account for approximately 60%, Goodpasture's Syndrome for approximately 20% of the cases. Fulminant pulmonary capillaritis can result in acute respiratory failure, more subtle courses are only detected by bronchoalveolar lavage. Renal biopsy displays extracapillary proliferating glomerulonephritis and renal immunohistology facilitates detection of the underlying systemic disease. By accelerating the diagnosis of the specific underlying disease, autoantibody testing fosters rapid initiation of treatment and thereby significantly improved the prognosis of pulmonary-renal syndrome. Intense immunosuppression with cyclophosphamide and glucocorticoids, augmented by plasmapheresis in the event of Goodpastures' syndrome, is the mainstay of therapy. Supportive measures as temporary ventilation and hemodialysis have further reduced mortality.

Temporary Hemodialysis Catheters as a Long‐term Vascular Access in Chronic Hemodialysis Patients

The objective was to review our experience with temporary, precurved, jugular catheters used for long-term vascular access in chronic hemodialysis patients. Thirty chronic hemodialysis patients, 14 men and 16 women, with an average age of 65.3 +/- 13.5 years (30-90 years), treated by dialysis for 1 month to 30 years (average +/- SD, 6.3 +/- 8.1 years), had single lumen, 'temporary' precurved non-tunneled jugular catheters placed into the right jugular vein as permanent vascular access, with 4% trisodium citrate as a locking solution and mupirocin at the exit site. Hemodialysis catheters were used for vascular access on average for 9.1 +/- 6.5 months, (1-22.7 months), and for a total of 271.7 months (8151 days). Average catheter functioning time was 3.1 +/- 1.9 months (0.5-10 months). The total number of side-effects was 55 (6.7/1000 catheter days), including 26 cases of thrombosis (3.2/1000 catheter days), 9 ruptures of the catheter (1.1/1000 catheter days), 15 catheter malfunctions (1.8/1000 catheter days), 2 exit site infections (0.2/1000 catheter days), 2 bacteremias (0.2/1000 catheter days), 1 avulsion of the catheter (0.1/1000 catheter days), and 2 catheters were removed because an AV fistula was successfully used. In 21 patients single-needle hemodialysis was performed, mean blood flow 251 +/- 16 mL/min (250-300), mean Kt/V 0.96 +/- 0.16 (0.72-1.27) and in 9 patients double-needle hemodialysis was performed (catheter and peripheral vein) with mean blood flow 252 +/- 14 mL/min (200-300), mean Kt/V 1.63 +/- 0.25 (1.21-1.96). 'Temporary' jugular single lumen non-tunneled hemodialysis catheters, with 4% citrate as locking solution and mupirocin ointment at the exit site provided good long-term vascular access with acceptable functioning time and low infection rate. The main reasons for catheter exchange or removal were malfunction and mechanical damage of the catheter.

A Randomized, Controlled Trial of a New Vascular Catheter Flush Solution (Minocycline-EDTA) in Temporary Hemodialysis Access

We previously demonstrated that minocycline-EDTA was efficacious at preventing catheter-related bloodstream infections (BSIs) in three patients with recurrent infections. This study compared heparin with minocycline-EDTA as flush solutions used among dialysis patients with central venous catheters, a high-risk group for catheter-related BSI. Patients were enrolled within 72 hours of catheter insertion and randomized to receive heparin or minocycline-EDTA as a flush after each dialysis session. Each syringe containing flush solution was wrapped in orange plastic to conceal the type of solution it contained. Patients were observed for evidence of infection and catheter thrombosis. After catheters were removed, cultures were performed to determine whether microbial colonization had occurred. During a 14-month period, 60 patients were enrolled (30 in each group). The two groups had similar demographics and underlying diseases. Catheter survival at 90 days was 83% for the minocycline-EDTA group versus 66% for the heparin group (P = .07). Significant catheter colonization, a surrogate measure of catheter-related infection, was significantly more frequent in the heparin group (9 of 14 vs 1 of 11; P = .005). There was only one catheter-related bacteremia and it occurred in the heparin group. When compared with heparin, minocycline-EDTA had a better 90-day catheter survival (P = .07) and a decreased rate of catheter colonization. This pilot study warrants a larger prospective, randomized trial.

Incidence of contrast nephropathy from cerebral CT angiography and CT perfusion imaging

The incidence of contrast-induced nephropathy was examined in 1,075 patients receiving routine CT angiography and CT perfusion brain imaging at a single institution. Fifty-two patients had a creatinine rise of > or =0.5 mg/dL. In four patients (0.37%), the administration of IV contrast medium possibly contributed to renal failure. Two patients (0.19%) received temporary hemodialysis during hospitalization. The incidence of contrast nephropathy in neurovascular patients is low.

Peritoneal dialysis patient survival: a comparison between a Swedish and a Korean centre

Dialysis patient mortality remains high, and this high mortality may be due to many factors. In peritoneal dialysis (PD) patients, old age, co-morbid diseases, malnutrition, low residual renal function (RRF) and a high peritoneal transport rate have been shown to influence survival, but the relative importance of these factors may differ between different patient populations. Besides, centre practice patterns may differ between centres and may influence patient survival. In addition, the literature suggests that dialysis patient survival may be better in Asian than in Caucasian patients. The influence of centre and patient characteristics on patient survival was investigated in 132 Korean and 106 Swedish incident PD patients, who underwent initial biochemical measurements and assessment of adequacy of dialysis, nutritional status, RRF and peritoneal transport characteristics. At the start of PD, Korean patients had a higher prevalence of diabetes, peritoneal Kt/V(urea), peritoneal creatinine clearance and peritoneal fluid removal, and lower body mass index, RRF and dialysate to plasma creatinine concentration ratio (D/P Cr) compared with Swedish patients. Significantly more patients from Korea were placed on temporary haemodialysis before PD (100 out of 132) when compared with Swedish patients (21 out of 106). During the follow-up, there was a significantly higher rate of transfer to other units in Korea and a significantly higher rate of kidney transplantation in Sweden. On Kaplan-Meier analysis, overall patient survival did not differ and relative risk for death was also not different between the two centres even after adjustment for age, diabetes, cardiovascular disease, RRF and D/P Cr. On Cox proportional hazards multivariate analysis, age, diabetes, RRF and D/P Cr were found to be independent predictors of mortality in the combined cohort of patients. While age, diabetes and D/P Cr were independent predictors of mortality in Korean patients, age and RRF independently predicted mortality in Swedish patients. Although there were significant differences in centre and patient characteristics, we were unable to confirm a survival advantage for Korean over Swedish PD patients. The results of this study suggest that the reported difference in survival between Asian and Caucasian dialysis patients may have been due, in part, to differences in centre and patient characteristics rather than to race as such. The genetic influence on patient characteristics remains, however, to be elucidated.

Conversion of temporary hemodialysis catheters to tunneled hemodialysis catheters

To determine the feasibility and clinical outcomes of conversion of temporary to tunneled hemodialysis catheters using the same venous insertion site. Data from 42 patients with existing temporary hemodialysis catheters referred for placement of tunneled hemodialysis catheters were retrospectively reviewed. In these patients, the temporary catheter was exchanged for a peel-away sheath, and a tunneled catheter was inserted using the existing venous access site. Technical success, procedural complications, and clinical outcomes were evaluated. Hemodialysis records were reviewed to assess catheter patency during a 30-day follow-up period. The study group consisted of 20 males and 22 females (mean age: 58 years). All 42 temporary catheters were successfully converted to tunneled hemodialysis catheters without immediate procedure-related complications. Follow-up data were available for 32 patients (total: 3038; median 71 catheter days). Nine catheters were removed for infection, yielding a catheter infection rate of 0.30/100 catheter days; three catheters were removed for blood flow <200 ml/min. 13 patients had catheters removed when catheters were no longer needed. Three patients died with working catheters. The patency rate was 72% at 30 days, with four catheters functioning at the end of the study period. Conversion of a temporary hemodialysis catheter to a tunneled hemodialysis catheter using the same venous insertion site is a safe procedure that avoids complications associated with venotomy and allows conservation of other central venous access sites. Patency and infection rates in these catheters are comparable to several studies of catheter exchange and de novo placement of tunneled hemodialysis catheters.

29 Temporary Hemodialysis Catheters as a Long Term Vascular Access in Chronic Hemodialysis Patients

Background In chronic hemodialysis patients with exhausted arteries and veins in whom AV fistula or AV graft can not be performed any more, hemodialysis catheters become the last resort, either tunneled, so called “permanent”, or non‐tunneled, so called “temporary” catheters which can be usefully used for a longer period of time than a permanent vascular access.The aim of our clinical study was to asses temporary, precurved, jugular catheters as permanent vascular access in chronic hemodialysis patients.Methods Thirty chronic hemodialysis patients, 15 men, 16 women, mean age 65.3 ± 13.5 years (range 30–90), with average dialysis treatment time of 6.3 ± 8.1 years (range 1 month−30 years), have had single lumen, “temporary” precurved nontunneled jugular catheters (Medcomp, USA) as permanent vascular access. Catheters were placed into right internal jugular vein, by Seldinger's technique, in local anesthesia (2% lidocain), locking solution was 4% trisodium citrate. Catheters were placed by experienced nephrologists, with ultrasound assistance, dressing was performed by dialysis nurses. Mupirocin was applied at the exit site after each hemodialysis. In the case of malfunction, thrombosis or infection, the catheter was replaced with the new one, using a guidewire. Prophylactic ceftazidime in a single dose was used after the catheter`s exchange. Unfractionated or fractionated heparin was anticoagulant.Results Hemodialysis catheters were used for vascular access on average for 9.1 ± 6.5 months, range 1–22.7 months, total 271.7 months or 8151 days. Average catheter running time was 3.1 ± 1.9 months, range 0.5–10 months. Total number of side effects was 57, 7.0/1000 catheter days; 26 thrombosis, 3.2/ 1000 catheter days; 9 ruptures of the catheter, 1.1/1000 catheter days; 15 malfunction, 1.8/1000 catheter days; 2 exit site infections, 0.2/1000 catheter days; 2 bacteremias, 0.2/1000 catheter days; 1 avulsion of the catheter, 0.1/1000 catheter days; and 2 catheters were removed because AV fistula was successfully used.In 21 patients single needle hemodialysis was performed, mean blood flow 251 ± 16 mL/minute, range 250–300, mean KT/V 0.96 ± 0.16, range 0.72–1.27and in 9 patients double needle hemodialysis was performed (catheter and peripheral vein) with mean blood flow 252 ± 14 mL/minute, range 200–300, mean KT/V 1.63 ± 0.25, range 1.21–1.96.Conclusions ‘Temporary’ jugular single lumen non‐tunneled hemodialysis catheters provide good long term vascular access with acceptable functioning time and low infection rate. KT/V for single needle hemodialysis was rather low, however it significantly improved when double needle hemodialysis was performed. The main reasons for catheter removal was thrombosis, malfunction, and mechanical damage of the catheter.

Haemodialysis catheter‐related right transverse cervical artery pseudoaneurysm and treatment by coil embolization

In patients with end-stage renal disease, temporary placement of venous catheters for haemodialysis (HD) is often necessary, and the right internal jugular (RIJ) vein is the usual preferred site of HD catheter placement. We report here a patient who experienced complications because of the development of a pseudoaneurysm of the transverse cervical artery following an apparently uneventful RIJ vein cannulation for temporary HD, using the blind landmark-guided technique. This is a rare complication of RIJ vein cannulation and HD catheter placement. The pseudoaneurysm presented 3 weeks after the procedure and was diagnosed by using colour-Doppler ultrasound, followed by an angiogram, and it was successfully occluded using endovascular coil embolization.

Right atrial thrombus as a complication of a temporary haemodialysis catheter--a potentially avoidable complication

Right atrial thrombus as a complication of a temporary haemodialysis catheter--a potentially avoidable complication

Right Atrial Thrombi Complicating use of Central venous Catheters in Hemodialysis

There has been an increase in the use of central venous catheters for temporary hemodialysis access. In this report, we describe a case series of 12 patients on hemodialysis who developed intracardiac clots associated with the use of central venous catheters, their outcomes and review the literature on this syndrome. Retrospective, single-center case series of 12 patients with right atrial thrombi associated with central venous catheter use for dialysis vascular access. These patients were treated between June 1, 2001 and June 30th 2002 at the three University of Rochester affiliated dialysis clinics. The medical records of these patients were reviewed to obtain information concerning demographics, dialysis history, dates of catheter insertion, catheter complications, identification and dimensions of intracardiac thrombi, echocardiographic data, and outcome of anticoagulant therapy. Right heart thrombi were identified in 12 patients in our hemodialysis population over the study interval. Anticoagulation for 6 months led to clot resolution in more than 50% of our patients. Bacteremia recurred in 6 patients (50%), in spite of catheter replacement. There was zero mortality related to presence of clots in the short term. One patient with non-bacteremic right atrial thrombus suffered sudden cardiac arrest, but was successfully resuscitated. Right atrial thrombi may occur in hemodialysis patients who use central venous catheters for dialysis access. These clots are frequently found in the right atrium or right atrial-superior vena caval junction. Ten of 12 patients (83%), had catheter-associated bacteremia, but the precise relationship between bacteremia and intracardiac clots is unclear. Chronic anticoagulation for 6 months lead to resolution of these clots in more than 50% of patients in our series.

A Prospective Randomized Study to Compare Ultrasound-Guided with Nonultrasound-Guided Double Lumen Internal Jugular Catheter Insertion as a Temporary Hemodialysis Access

Internal jugular venous catheters (IJVC) for hemodialysis are a commonly employed temporary vascular access for hemodialysis. Most hospitals still follow the use of blind technique, which uses anatomical landmarks. Even in the most experienced hands this procedure has a variable success rate. Ultrasound guidance can decrease the incidence of periprocedural complications and improve the success rate. In this randomized study we compared the procedure success rate and periprocedural complications in patients undergoing ultrasound guided vs. nonultrasound guided IJVC insertion for a temporary hemodialysis access. Methods. All patients subjected to insertion of an IJVC between March 2004 and June 2004 were enrolled into the study, randomized to either the blind (group A) or ultrasound guided (group B) procedure, which uses a portable ordinary ultrasound machine without a needle guide. The aseptic Saldinger technique was used for catheterization in both the groups. Baseline characteristics of patient and periprocedural events were recorded. Results. A total of 60 patients were randomized, 30 patients each in two groups. First attempt venous cannulation success rate was 56.7% in group A compared to 86.7% in group B. Chance of occurrence of adverse outcome was significantly more in the blind procedure (P = 0.020). A post-procedure chest radiograph done in all patient showed no complications. Conclusion. Ultrasound guided procedure for internal jugular vein catheter insertion using an ordinary ultrasound machine was significantly safer and more successful as compared to the blind technique.

Partial nephrectomy for patients with a solitary kidney: the Memorial Sloan‐Kettering experience

To report the experience of partial nephrectomy in patients with a solitary kidney at one institution, with analysis of renal function, complications, oncological efficacy and survival. We identified 54 consecutive patients with a solitary kidney who had a partial nephrectomy between December 1989 and July 2003. Variables examined included patient age and gender, renal function, renal ischaemia time, surgical margin status and complications. Pathological features, e.g. tumour size, histological subtype and tumour stage, were also assessed. Disease-free probability and overall and cancer-specific survivals were determined. The histological subtype was clear cell in 35 cases (65%), papillary in 10 (19%), oncocytoma in four (7%), chromophobe in two (4%), unclassified in one (2%) and multiple subtypes in two (2%). The median creatinine level before surgery was 14 mg/L, which increased to 16 mg/L 6 months afterward, and at 1 and 2 years after surgery it was 15 mg/L. Two patients developed end-stage renal disease requiring haemodialysis, one soon after surgery and another 8 years after nephron-sparing surgery. In all, 26% of patients developed at least one perioperative complication, with acute renal failure and urinary fistula being the most common. At 5 years the overall and cancer-specific survival, and disease-free probability were 68%, 88% and 73%, respectively. Partial nephrectomy is safe in patients with a solitary kidney, with an acceptable decline in renal function and low likelihood of requiring temporary or permanent haemodialysis. After an initial decline, renal function appears to stabilize during the first year.

Commentary

BACKGROUND Autosomal dominant polycystic kidney disease (PKD) is a hereditary disorder characterized by bilateral multiple renal cysts and early onset chronic renal failure. PKD patients tend to suffer their subarachnoid hemorrhage at a younger age. Unruptured aneurysms in PKD patients are not always innocuous, and proactive treatment has been indicated for these lesions. However, the management of PKD patients undergoing unruptured cerebral aneurysm surgery has been documented on only a few occasions. The purpose of this study was to better define the management of unruptured cerebral aneurysms in patients with PKD. METHODS We present a retrospective review of the management of unruptured cerebral aneurysms in 16 patients with PKD. Eight patients were maintained through chronic hemodialysis whereas the remaining 8 patients did not require hemodialysis, at the time of treatment of their cerebral aneurysms. The mean follow-up period was 24 months. RESULTS In the nonhemodialysis patients prophylactic hemodialysis was routinely performed after cerebral angiography to prevent deterioration of the pre-existing renal dysfunction. Microsurgical clipping of the aneurysm was performed in 15 patients (7 nonhemodialysis and 8 hemodialysis patients) and intravascular coil embolization was performed in 1 nonhemodialysis patient. One nonhemodialysis patient who underwent microsurgical clipping required a temporary hemodialysis after surgery, but the patient was not shifted to chronic hemodialysis. No patients developed postprocedural complications, and each showed an excellent recovery. CONCLUSION PKD patients with unruptured cerebral aneurysms can be safely treated with an appropriate treatment strategy including the use of prophylactic hemodialysis.

Management of unruptured cerebral aneurysms in patients with polycystic kidney disease

Background Autosomal dominant polycystic kidney disease (PKD) is a hereditary disorder characterized by bilateral multiple renal cysts and early onset chronic renal failure. PKD patients tend to suffer their subarachnoid hemorrhage at a younger age. Unruptured aneurysms in PKD patients are not always innocuous, and proactive treatment has been indicated for these lesions. However, the management of PKD patients undergoing unruptured cerebral aneurysm surgery has been documented on only a few occasions. The purpose of this study was to better define the management of unruptured cerebral aneurysms in patients with PKD. Methods We present a retrospective review of the management of unruptured cerebral aneurysms in 16 patients with PKD. Eight patients were maintained through chronic hemodialysis whereas the remaining 8 patients did not require hemodialysis, at the time of treatment of their cerebral aneurysms. The mean follow-up period was 24 months. Results In the nonhemodialysis patients prophylactic hemodialysis was routinely performed after cerebral angiography to prevent deterioration of the pre-existing renal dysfunction. Microsurgical clipping of the aneurysm was performed in 15 patients (7 nonhemodialysis and 8 hemodialysis patients) and intravascular coil embolization was performed in 1 nonhemodialysis patient. One nonhemodialysis patient who underwent microsurgical clipping required a temporary hemodialysis after surgery, but the patient was not shifted to chronic hemodialysis. No patients developed postprocedural complications, and each showed an excellent recovery. Conclusion PKD patients with unruptured cerebral aneurysms can be safely treated with an appropriate treatment strategy including the use of prophylactic hemodialysis.

Sirolimus and Thrombotic Microangiopathy after Allogeneic Stem Cell Transplantation.

Sirolimus (SRL) is a novel immunosuppressive agent that has been demonstrated to reduce GVHD and minimize morbidity after allogeneic stem cell transplantation (alloSCT). We have described a syndrome of thrombotic microangiopathy (TMA), characterized by microangiopathic hemolysis, thrombocytopenia, and renal dysfunction, whose incidence is increased when SRL is used in association with calcineurin inhibitors (CIs) but not with SRL monotherapy. To determine if SRL use potentiates the effects of CIs on TMA incidence and risk factors, we performed a retrospective cohort analysis of subjects who underwent alloSCT between 1997 and 2003.Methods: Subjects who received a SRL-containing GVHD prophylaxis after a myeloablative preparative regimen were compared with a cohort who received a non-SRL regimen. All subjects received CIs. Diagnosis of TMA required the simultaneous occurrence of: (1) creatinine elevation >2 mg/dL or >50% above baseline, (2) schistocytosis, (3) elevated LDH, and (4) no laboratory evidence of disseminated intravascular coagulopathy.Results: 111 patients who received SRL were compared with 216 patients who received no SRL during the first 100 days after alloSCT. The two groups of patients were balanced for demographic parameters; however, more patients in the SRL group received peripheral blood stem cells (50.5 vs. 18.1%, p<0.01) and had unrelated donors (58.6 vs. 42.6%, p<0.01). The incidence of TMA in the SRL group was 10.8% in comparison with an incidence of 4.2% in the non-SRL group (OR 2.57, p=0.03). Patients who received SRL developed TMA earlier than those who did not receive SRL (median 25 vs. 58 days, p=0.04). At the time of TMA diagnosis, median blood levels of immunosuppressive medications were in their respective therapeutic ranges: SRL (study group) 6.1 ng/ml, tacrolimus (study group) 9.9 ng/ml, tacrolimus (control group) 9.1 ng/ml; cyclosporine (control group) 418 ng/ml. In a multivariable logistic regression model, only the use of SRL (Adjusted Exact OR 3.49, p =0.02) and grade II-IV acute GVHD (Adjusted Exact OR 6.60, p = 0.0002) predicted the occurrence of TMA. Treatment of TMA consisted of discontinuation or dose adjustment of CIs. SRL was discontinued or dosed according to serum level. Two subjects in each group required temporary hemodialysis, and 3 subjects (1 SRL, 2 non-SRL) underwent plasmapheresis. 78% of surviving SRL-treated subjects regained normal renal function. No subject had a TMA recurrence if SRL was reintroduced. Overall survival after TMA diagnosis was better for SRL patients than non-SRL patients (58.3 vs. 11.1%, log rank p=0.02).Conclusion: SRL use is associated with an increased risk of TMA after alloSCT and may act by potentiating the effects of CIs. TMA associated with SRL appears reversible and does not affect overall survival after alloSCT. A careful monitoring strategy for TMA should be employed as part of a SRL-containing GVHD prophylaxis regimen.