Efficacy and safety of Palmaz stent insertion in the treatment of renal artery stenosis in kidney transplantation

Modified lymph node ratio improves the prognostic predictive ability for breast cancer patients compared with other lymph node staging systems

Background

Metastatic regional lymph nodes (LN) is a strong predictor of worse long-term outcome. Therefore, different LN staging systems have been proposed in recent years. In this study, we proposed a modified lymph node ratio (mLNR) as a new lymph node staging system and then compared the prognostic performance of mLNR with American Joint Committee on Cancer N stage, lymph node ratio (LNR) and log odds of metastatic lymph nodes in breast cancer patients.

Methods

Breast cancer patients who underwent surgery between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. Restricted cubic spline functions were calculated to characterize the association between variables and the risk of death. The Cox proportional hazards models were constructed to assess the predictive ability of different lymph node staging systems using the Akaike’s Information Criterion (AIC) and Harrell’s concordance index (C-index).

Results

A total of 264,096 breast cancer patients were enrolled and 187,785 (71.1%) patients had a limited number of LNs harvested. In the limited LN harvest cohort, the prognostic performance of LNR decreased and mLNR could greatly solve this problem. In addition, among the entire cohort, mLNR modeled as a continuous value had the best predictive ability (AIC: 922021.9 and C-index: 0.727) than other lymph node staging systems.

Conclusions

The predictive ability of LNR is restricted by a limited LN harvest. However, mLNR shows superiority to LNR and other lymph node staging systems especially in a limited LN harvest cohort, making mLNR the most powerful lymph node staging systems.

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We selected 264,096 patients, which is enough to support our conclusion.

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We used two indexes to fully verify the fit of different lymph staging systems.

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The mLNR improved the prognostic predictive ability best.

Salvage of hyperacute renal transplant hypoperfusion with stent placement: a case report

The authors report on a patient who underwent renal artery stent placement 6 hours after transplantation due to acute hypoperfusion of the transplant, which was diagnosed with intraoperative Doppler ultrasonography. Extensive atherosclerotic disease of the cadaveric transplant renal artery necessitated endarterectomy before creation of the anastomosis, and no further surgical options were considered feasible by the transplant surgeon. Six hours after the transplantation, percutaneous transluminal renal angioplasty and stent placement were performed, resulting in restoration of normal arterial flow and rescue of allograft function.

Posttransplant diabetes and hypertension: pathophysiologic insights and therapeutic rationale

New-onset diabetes after transplantation and hypertension are very common after renal transplantation and are associated with adverse graft and cardiovascular outcomes. A thorough understanding of the unique factors that operate in renal transplant recipients is essential for the proper evaluation and management of these important disorders. This review outlines the pathogenesis, diagnostic workup, and therapeutic rationale for diabetes and hypertension after transplantation.

Efficacy and safety of Palmaz stent implantation in the treatment of renal artery stenosis in renal transplantation

To verify the long-term efficacy and safety of Palmaz stent implantation in the treatment of transplant renal artery stenosis (TRAS), we reviewed the charts of 26 patients affected by TRAS and treated by percutaneous transluminal angioplasty (PTA) followed by permanent insertion of a Palmaz stent. The mean follow-up period was 43.31 +/- 33.6 months. The mean blood pressure fell significantly at 1 month after stenting (118 +/- 8.1 vs 101 +/- 7.8 mmHg; P < .0001); then remained stable. Renal artery blood flow, as determined by Doppler ultrasonography, was reduced from 352.5 +/- 56.5 to 157.3 +/- 53.7 cm/sec at 1 month after stenting (P < .0001). Renal function improved after stenting (serum creatinine 2.2 +/- 1.4 mg/dL preinsertion versus 1.72 +/- 1.05 at 3 years). In conclusion, in cases of severe or recurrent TRAS, stenting of the renal artery has proved to be an effective therapeutic tool. This method, which has low procedure costs and an extremely low complication rate has proved to be safe and to offer the potential of preserving luminal patency, improving the long-term efficacy of percutaneous angioplasty.

Transplant renal artery stenosis: outcome after percutaneous intervention

PURPOSE

To assess the outcome of percutaneous transluminal angioplasty (PTA) and stent placement as the primary treatment for transplant renal artery stenosis (TRAS).

MATERIALS AND METHODS

A retrospective review of PTA and stent placement procedures performed for TRAS from April 1997 to July 2003 was conducted. Reviewed parameters included technical success, date of transplantation, dates of percutaneous intervention, mean arterial blood pressure, number of blood pressure medications, and serum creatinine level before and after intervention. Twenty-one interventions were performed in 18 allografts. The primary clinical indication for imaging and treatment was increased creatinine level in 12 allografts and hypertension in six allografts. Patency rates were estimated with use of the Kaplan-Meier method.

RESULTS

The technical success rate of PTA/stent placement was 100% and the clinical success rate was 94% (17 of 18 allografts). Thirteen interventions involved PTA alone, with eight combined PTA and stent insertions. The mean preintervention serum creatinine level among 12 allografts presenting with elevated creatinine levels was 2.8 mg/dL +/- 1.4 (SD), compared with a 1-month postintervention mean of 2.2 mg/dL +/- 0.7 (P = .03). Of six allografts that presented with hypertension, significant improvement was seen between the preintervention and 1-month postintervention mean systolic (174 mm Hg vs 135 mm Hg, P = .003) and diastolic (99 mm Hg vs 82 mm Hg, P = .02) pressures. These patients required a mean of 2.3 medications for blood pressure control before intervention, compared with a mean of 1.0 medications at 1 month after intervention (P = .002). Primary patency rates at 3, 6, and 12 months (+/-95% CI) were 94% +/- 6%, 72% +/- 12%, and 72% +/- 12%, respectively. Secondary patency rates at 3, 6, and 12 months (+/-95 CI) were 100%, 85% +/- 10%, and 85% +/- 10%, respectively. Mean follow-up time was 27 months. Of the eight allografts that underwent stent placement, all eight remained patent at last follow-up (mean, 18.3 months +/- 9.2). One major complication of a puncture site pseudoaneurysm occurred (5%).

CONCLUSION

Primary treatment of TRAS with PTA with or without stent placement has good intermediate-term patency and is associated with significant early improvement in blood pressure and creatinine level.

Percutaneous treatment of transplant renal artery stenosis in children

Percutaneous treatment of renal artery stenosis (RAS) is an accepted procedure and numerous reports have been published. However, experience with its use in RAS in the transplanted kidney in children is scarce. Since 1994 we have diagnosed RAS in seven children with the use of Doppler ultrasonography (US), confirming it with percutaneous angiography (PAG). In six of the seven patients percutaneous transluminal angioplasty (PTA) was performed. In one patient a metallic stent was placed due to the extension of the arterial lesion, and a second stent was placed in another child when a re-stenosis was diagnosed 1 month after the PTA. All patients presented with hypertension (de novo or 30% increase over previous values). After ruling out acute rejection, calcineurin inhibitor toxicity, and urinary obstruction, US was performed and, when an increase in arterial flux velocity was registered, PAG was also performed. Six children showed an increase in serum creatinine (Cr) and proteinuria. Blood pressure decreased after the procedure and Cr returned to previous levels in all children. One of the grafts was lost due to chronic transplant rejection 7 years later. The other children have a functioning kidney. Although this is a small group of patients, the consistently good results and the lack of reported experience prompted us to communicate our preliminary observation.