Evaluation of canine renal transplants with pulsed Doppler duplex sonography

Preliminary studies of human renal transplants suggested that pulsed Doppler sonography may complement other studies of renal transplant dysfunction. To further evaluate the Doppler technique, 11 dogs who received renal transplants were examined a total of 50 times. No antirejection chemotherapy was used, and following rejection the kidneys were removed and examined histologically. The canine transplants underwent accelerated acute or hyperacute rejection. A pulsed Doppler index (PDI) was derived to quantitate patterns of renal blood flow and peripheral vascular resistance. Arterial Doppler signals were obtained from renal transplant branch vessels in vivo and the PDI consistently fell as rejection occurred. No arterial signals were obtained from one kidney which was subsequently proven to have arterial thrombosis. Pulsed Doppler analysis provides new information about renal transplant blood flow patterns and may demonstrate evidence of rejection and renal arterial occlusion.     

Duplex Doppler sonography in patients with acute renal colic: Prospective study and literature review

PURPOSE: To determine the value of duplex Doppler sonography in the diagnosis of acute urinary obstruction. MATERIALS AND METHODS: In 46 healthy individuals and 42 patients with urinary obstruction confirmed by intravenous urography, 176 kidneys were examined with duplex Doppler sonography. The mean intra-arterial resistive index value and the difference of mean resistive index values between both kidneys were determined for each person. Resistive index and delta resistive index values were compared with urographic findings in the 42 patients. RESULTS: In the 46 healthy individuals, the mean resistive index and delta resistive index values were 0.59 +/- 0.05 and 0.03 +/- 0.01. In the 14 patients with complete urinary obstruction, these values were 0.70 +/- 0.06 and 0.09 +/- 0.02, whereas in the 28 patients with partial urinary obstruction, these values were 0.64 +/- 0.06 and 0.03 +/- 0.05. Urographic findings and duplex Doppler sonography were correlated in the 42 patients, with a resistive index = 0.65 and delta resistive index = 0.05 as discriminatory thresholds for obstruction. In patients with complete obstruction, the diagnostic sensitivity of these values was 64% and 100% with a specificity of 82% and 89%, respectively. In patients with partial obstruction, the sensitivity of these values was 54% and 46% with a specificity of 82% and 89%, with respect to the control group of healthy individuals. CONCLUSION: Delta resistive index is a very sensitive and specific parameter in the sonographic diagnosis of complete urinary obstruction but insensitive in partial urinary obstruction. Duplex Doppler sonography is recommended in cases where intravenous urography is contraindicated.     

Evaluation of penile perfusion by color-coded duplex sonography in the management of erectile dysfunction

The etiology of erectile dysfunction is wide ranging. Penile vascular disorders may result in impaired erection or complete impotence. Almost 30% of erectile dysfunction is due to the presence of systemic disease which affects the blood supply to the penis. The intracavernosal injection test with prostaglandin E1 alone offers limited information on the vascular status. In accordance with the increasing demand for less invasive procedures, penile color-coded duplex sonography (CCDS) combined with the pharmaco-erection test represents a first-line noninvasive approach to investigate arterial and veno-occlusive function. Peak systolic velocity and a change in cavernous artery diameter are indicators of arterial inflow, while the pathological end diastolic velocity and resistance index point out veno-occlusive dysfunction. The combined investigation of power and standard color Doppler ultrasound may yield more details of penile vascular anatomy.     

彩色超声在移植肾急性排斥反应和急性肾小管坏死鉴别中的应用

目的 :探讨彩色超声检查在肾移植术后急性排斥反应和急性肾小管坏死鉴别诊断中的应用价值。方法 :回顾性分析 5 86例临床资料完整的肾移植病例术后彩色超声检查结果并结合临床症状、生化指标及病理检查结果 ,分为正常对照组、急性排斥组 (AR组 )和急性肾小管坏死组 (ATN组 )进行分析。结果 :①AR组长径、皮质厚度明显大于对照组 (P <0 .0 5 ) ,ATN组与对照组之间差异无统计学意义。②AR组尚可见到肾锥体增大、膨隆、回声减低等二维声像图变化。③以动脉血流阻力指数 (RI)≥ 0 .7为标准 ,AR组和ATN组RI值明显高于对照组 ,AR组和ATN组之间差异无统计学意义 (P >0 .0 5 )。④经有效抗排斥治疗AR组RI值平均 1周左右先于二维声像变化恢复 ,二维声像图变化平均于 4周左右恢复 ,而ATN组RI值平均在 3周左右恢复正常。结论 :彩色超声在移植肾急性排斥反应和急性肾小管坏死鉴别中具有良好的应用价值。     

The use of duplex Doppler ultrasonography to evaluate renal allograft dysfunction

This study evaluated the utility of duplex Doppler sonograms (DS) and the resistive index (RI) in the identification and differential diagnosis of various causes of renal allograft dysfunction. The efficacy of DS and RI was studied either during acute episodes of allograft dysfunction or during periodic posttransplantation longitudinal analyses. The unique features of each renal allograft results in poor correlative value for single isolated measurements of RI. We observed that the highest RIs were in ATN and that an RI of 0.9 was not specific for acute vascular rejection. Also, an RI of 0.9 was rare in acute cellular rejection. RI could not distinguish acute rejection, chronic rejection, CsA toxicity, or obstruction, although the mean RI was significantly different from normal in these groups. Serial studies of RI did document a change at the time of a clinical event compared to baseline. It is concluded that RI is not specific to any one clinical entity.     

Doppler sonography and color duplex imaging for planning a perforator flap

The most critical factor to predict viability for any muscle perforator flap is an adequate circulation. Therefore, it is advantageous during preoperative planning to have the capability to localize the requisite cutaneous perforator. Color duplex imaging fulfills this requirement and permits the identification of additional characteristics, including caliber, course, and flow velocity of essential perforators and any source vessel. Nevertheless, with the current state of technology, Doppler sonography remains a more rapid, convenient, and simpler method for perforator localization.     

Evaluation of transplant renal artery blood flow by Doppler sound-spectrum analysis

Doppler ultrasonography sound-spectrum analysis (SSA) was used to evaluate blood flow in the transplanted kidney and its renal artery. Seven patients with posttransplant hypertension and a bruit over the transplanted kidney were screened for renal artery stenosis (RAS). In five patients, RAS was diagnosed by SSA, and in two it was not. These findings were confirmed by subsequent angiography in all patients. Three patients studied after surgical correction of their RAS had improvement in their SSA patterns. Fourteen hypertensive patients with a cause other than RAS were evaluated by SSA. None of them had SSA findings suggestive of RAS. Doppler ultrasonography with SSA is an effective, noninvasive technique of monitoring transplant renal blood flow, especially in the screening of hypertensive transplant recipients for transplant RAS.     

Spinal gout in a renal transplant patient: a case report and literature review

BACKGROUND: Gout in the axial spine is rare. We present a case report on a renal transplant patient who developed fever and acute back pain at the L5 through S1 level secondary to sodium urate deposits. We review the literature on this rare disease and propose a management algorithm based on a resulting analysis. CASE DESCRIPTION: A 37-year-old man with a history of gout and a renal transplant for IgA nephropathy presented with acute back pain and fever without evidence of neurological deficits. Magnetic resonance imaging revealed a uniformly contrast-enhancing infiltrative process involving the right pedicle, lamina, and inferior facet of the L5 vertebra. Computed tomography-guided needle biopsy revealed a friable white tissue consistent with sodium urate crystals. Conservative treatment with steroids and narcotics was used with good symptomatic relief. CONCLUSION: Although few cases of gout involving the spine have been reported, its prevalence is likely grossly underestimated. Most patients have a history of gout and have elevated levels of serum urate level on presentation. The disease most commonly involves the lumbar spine. Patients usually have neurological deficits on presentation, and surgical decompression produces favorable outcomes. However, conservative medical management is appropriate for those with back pain only. Aggressive control of hyperuricemia is essential regardless of the method of treatment.     

Laparoscopic transperitoneal radical prostatectomy in renal transplant recipients: a review of the literature

OBJECTIVES

To report our experience with laparoscopic radical prostatectomy (LRP) for the treatment of localized prostate carcinoma in two renal transplant recipients and a review of the literature.

PATIENTS AND METHODS

We retrospectively identified all patients who had undergone LRP for clinically localized prostate cancer between 2002 and 2008 at our institution (n = 1150). Of these patients, two were renal transplant recipients (one with donor renal transplant cadaver and the other with prior transplantectomy). We reviewed all available clinicopathological data and the scientific literature.

RESULTS

The two patients underwent successful LRP with no major complications. The mean (range) operative time was 200 (180–220) min with a mean estimated blood loss of 300 (200–400) mL. There were no changes in renal graft function as measured by serum creatinine level. At pathology, the surgical margins were negative and disease was organ‐confined in each case. The two patients tolerated the procedure well and had a mean (range) hospital stay of 3.5 (3–4) days.

CONCLUSIONS

The data from our two patients suggest that LRP, as an accepted minimally invasive treatment for a middle‐aged man with organ‐confined prostate cancer, is a technically feasible and safe treatment of localized prostate cancer in renal transplant recipients.     

Acute thrombosis of the renal transplant artery: a case report and review of the literature

Acute thrombosis of the renal transplant artery is a known but unusual complication of renal transplantation usually occurring in the first month. Reported here is a case of acute renal artery thrombosis in a well functioning long-term renal allograft in which there was clear angiographic evidence of a normal renal artery two years earlier.     

Acute renal failure due to leptospirosis in a renal transplant recipient: a brief review of the literature

We present the case of a 43-year-old renal transplant patient who presented with fever, malaise, pruritus, headache, and severe jaundice of 3-week duration following work in a rice field. He was found to have acute renal failure and severe hyperbilirubinemia with a positive serum leptospira antibody titer, making the diagnosis of Weil's disease. The patient responded to reduction in immunosuppressive medications and intravenous penicillin therapy with no need for dialysis. This is the second case of leptospirosis in a kidney transplant patient reported in the English literature.     

Intraoperative renal duplex sonography: a valuable method for evaluating renal artery reconstructions.

OBJECTIVES: to determine the ability of duplex sonography to intraoperatively detect technical problems with renal artery reconstructions. DESIGN: retrospective evaluation of a standard protocol. PATIENTS AND METHODS: the outcome of intraoperative duplex was compared with postoperative angiography, surface duplex, MRA, echo or direct inspection in case of re-exploration in 77 renal artery reconstructions in 62 patients. These included six extracorporeal reconstructions, eight and 17 reconstructions with an artery and autogenous vein respectively, 10 renal artery re-implantations in the aorta (prosthesis), 32 endarterectomies and four reconstructions of kidney transplant vessels. RESULTS: intraoperative duplex was normal in 67/73 reconstructions with sufficient data. In six cases technical problems were revealed by intraoperative duplex and the reconstruction was re-explored. After re-exploration intraoperative duplex was normal in all cases. Confirmatory studies demonstrated normal results in 61/64 reconstructions with normal intraoperative duplex and abnormal results in 6/6 reconstructions with technical problems revealed by intraoperative duplex. Three reconstructions with normal intraoperative duplex occluded as demonstrated by angiography less than 2 weeks after surgery. CONCLUSIONS: renal duplex sonography is a valuable method available for intraoperative detection of technical problems. Haemodynamic duplex data were less important than B-mode imaging in discriminating between normal and abnormal reconstruction.     

Evaluation of the vertebral arteries with duplex sonography

Using duplex sonography, we have routinely evaluated the vertebral arteries as part of the carotid artery examination in 453 consecutive patients over a 6-month period. Sixty-two of these 906 vessels could not be adequately evaluated, primarily because these vessels lay too deep within the vertebral structures, resulting in a technical failure rate of 6.8%. For the remaining 844 vessels, 74.4% were considered normal by Doppler flowmeter spectral analysis. Angiographic correlation was available for 224 vessels; of 155 judged normal by duplex sonography, 144 (93%) were shown to be normal or have only mild atherosclerotic disease. Eleven vessels were considered either occluded or to have severe disease by duplex sonography, and angiography showed this to be the case in 10 (91%) vessels. Unusually strong vertebral artery flow was associated with hemodynamically significant carotid or contralateral vertebral atherosclerotic disease or subclavian steal 82% of the time. Twelve cases of subclavian steal, only one of which was symptomatic, were identified by duplex sonography; four of these were confirmed by angiography. Angiographic correlation was available for 229 vessels in which duplex evaluation showed vertebral artery flow to be moderately damped. In 11 of these (38%), angiography showed greater than 50% stenosis. Angiography judged the remaining 18 vessels in this group normal; these vessels may represent a small subgroup of patients with normal anatomy or only mild atherosclerotic disease, but with hemodynamic dysfunction that can be identified with the duplex technique.     

Bladder carcinoma among live-donor renal transplant recipients: a single-centre experience and a review of the literature

OBJECTIVES

To present our experience with bladder cancer among a renal transplant population and to review critically the relevant literature.

PATIENTS AND METHODS

In all, 1865 renal graft recipients were followed for a mean (sd ) of 6.5 (5) years. Seven recipients (all men) developed a urothelial bladder tumour. The stage and grade of the tumours were determined. The method of the treatment was selected on the basis of the tumour characteristics and graft function. Patients were regularly followed; the endpoints were cancer‐specific survival, recurrence or metastasis.

RESULTS

All patients presented with gross haematuria. There was non‐muscle‐invasive disease in two patients who were treated by transurethral resection and adjuvant intravesical bacille Calmette‐Guérin immunotherapy. One patient died 24 months later due to complications of end‐stage renal disease. To date the second patient is alive and free of the recurrence. Five recipients with muscle‐invasive disease had a radical cystectomy and orthotopic bladder substitution. The mean (sd ) time to the last follow‐up or death was 14.6 (3.1) months. Three patients died with stable graft function; two from distant metastasis and one from a cerebrovascular stroke. The remaining two patients are still alive, free of disease and with good graft function.

CONCLUSIONS

Urothelial bladder tumours are generally uncommon. The presence of haematuria in renal allograft recipients should be thoroughly investigated. Early diagnosis and prompt treatment are required for managing such tumours, because they are aggressive. Orthotopic bladder substitution is feasible with a good functional outcome for patients in whom cystectomy is indicated.