Radiofrequency ablation of renal cell carcinoma

Small renal cell carcinomas of less than 4 cm diameter have been detected increasingly in asymptomatic patients because of the widespread use of cross-sectional imaging. Radical or partial nephrectomy is generally considered the reference for the treatment of a solitary renal cell carcinoma. However, for those patients who are not candidates for surgery, minimally invasive procedures may be desirable. Although percutaneous radiofrequency ablation for the treatment of renal cell carcinoma is a recent innovation, the results of preliminary clinical series and animal studies are encouraging, and show it to be technically feasible with minimal morbidity. In this article, we review the technique, indications, imaging findings, as well as the results of clinical and animal studies of radiofrequency ablation for the treatment of renal cell carcinoma.     

Percutaneous transluminal renal angioplasty in the patient with a solitary functioning kidney

Since the introduction of percutaneous transluminal renal angioplasty, it has become established as an effective treatment for the correction of renovascular hypertension or the preservation of renal function. However, there has been a general reluctance to use it or other interventional procedures in any patient with a solitary functioning kidney. We attempted renal angioplasty in 11 patients each of whom had a solitary functioning kidney. All 11 had had either a previous contralateral nephrectomy or an autonephrectomy from chronic arterial occlusion. The patients ranged in age from 42 to 81 years. In nine of the 11 patients, a catheter was negotiated across the stenosis, and the lesion was dilated successfully. In two, the lesion could not be crossed. In the group of nine patients whose lesions were dilated successfully, clinical follow-up (2-180 weeks) revealed that hypertension was cured in four and improved in five. Of the two patients in whom angioplasty was not possible, one required emergency renal bypass surgery and the other had no change in renal status. Renal function test results after the procedure were variable and did not correlate with decreases in blood pressure. We conclude that percutaneous renal angioplasty is a satisfactory alternative to surgery for the treatment of renovascular hypertension or the preservation of renal function in a patient with a solitary functioning kidney.     

Urinoma formation following renal mass cryoablation treated with nephroureteral stent placement

Renal cryoablation (CA) has become an accepted treatment option for patients with small renal tumors and co-morbidities that make them less favorable for surgical intervention. Complications from renal CA have been previously reported and are generally associated with increasing size and central location of the tumor. Ureteral injury from renal CA, although rare, can be difficult to manage and may require complex surgeries in patients who are poor surgical candidates to begin with. We report a case of a renal mass CA complicated by proximal ureteral necrosis and transection, treated with multiple minimally invasive procedures ultimately resulting in successful bridging of the necrotic segment with nephroureteral stent and thus avoiding major surgery.     

胡桃夹综合症的介入治疗

目的:提高对胡桃夹综合征的认识,探讨NCS的腔内治疗。方法:回顾性分析山东大学附属省立医院血管外科2009年5月～2011年3月收治的4例胡桃夹综合症患者的临床资料,行左肾静脉腔内治疗。结果:4例患者均手术成功,肉眼血尿于7天后减轻,10～14天完全消失,镜下血尿15～30天完全消失。2例术前精索静脉曲张患者于术后3周消失;1例术前腰部不适症状患者术后2周消失;1例术前尿蛋白患者于术后2周恢复正常。随访(13±0.3)个月。症状均无复发,尿常规检查末见异常,B超检查:4例患者肾形态、血流灌注正常,肾静脉支架脉通畅。结论:血管腔内治疗微创、简单,术中准确测量、精确放置支架及术后严格抗凝治疗是治疗成功的关键和保证。     

Urologic complications following renal transplantation: role of interventional radiologic procedures

Seventy renal transplant recipients with suspected urologic problems underwent interventional radiologic procedures for further diagnosis and treatment. We found that 28 patients did not have urologic complications. The other 42 patients demonstrated a total of 62 complications, including 40 cases of obstruction, 12 cases of extravasation, and ten collections of pararenal fluid. Ultrasound and nuclear renal scans with both technetium-99m DTPA and iodine-131 hippuran were found to be sensitive screening techniques for the detection of these complications. Fifty of the 51 abnormalities were detected using a combination of these techniques. Percutaneous methods alone were successful in treating 15 urinary obstructions, eight pararenal fluid collections, and five urinary extravasations. We encountered six procedure-related complications, and there were three delayed infectious complications that were related to indwelling nephrostomy tubes. One of these three complications resulted in death. The results of our study suggest that invasive radiologic procedures can be safely used to diagnose and treat urologic complications in renal transplant recipients.     

Stab wounds of the renal artery branches: angiographic diagnosis and treatment by embolization

Renal artery branch injury resulting from stab wounds of iatrogenic origin or street violence is an important cause of renal hemorrhage. Over a period of 10 years we accurately diagnosed the injury and successfully managed the associated hemorrhage in 15 patients by using angiography and percutaneous embolization techniques. Nine branch injuries in eight patients were due to street knifings and seven injuries were complications of invasive medical procedures (four from renal biopsy, two from nephrostolithotomy, and one from nephrostomy). All patients had gross hematuria at the time of angiographic evaluation. False aneurysms were present in six patients (one with associated frank extravasation), false aneurysm/arteriovenous fistula in three, false aneurysm/arteriocaliceal fistula in one, and isolated arteriovenous fistula in two. Frank extravasation without associated false aneurysm/arteriovenous fistula was present in two. One patient had two injuries, an upper-pole false aneurysm and a lower-pole false aneurysm/arteriovenous fistula. In the eight patients injured in street knifings, hematuria recurred after surgical exploration and treatment. None of the 16 injuries involved the main renal artery. Gelfoam was used for embolization of nine lesions and steel coils for four. Three others were treated with Gelfoam plus coils. Hemostasis was achieved in all and none required subsequent surgery. Renal tissue loss was small to moderate (less than 30%) in 12 patients and large (30-50%) in three patients. Transient postembolization hypertension occurred in one of the latter. We consider selective angiography/embolization to be an effective and safe means for diagnosing and treating wounds of the renal artery branches.     

Percutaneous nephrostomy. A 5-year experience

The authors report their experience with percutaneous nephrostomy in the treatment of acute renal failure due to ureteral obstruction. One hundred and forty-three patients were treated with the positioning of 218 percutaneous nephrostomy catheters under fluoroscopic guidance. If performed as soon as possible, this percutaneous diversion provides a rapid improvement in renal function and allows an accurate staging of the lesion, as well as correct therapeutic indications. In many cases of urinary obstruction interventional radiology procedures represent a valid and successful alternative to more invasive palliative surgery.     

Radiofrequency ablation for tumor-related massive hematuria

To determine whether radiofrequency (RF) ablation targeting the tumor-collecting system interface has a durable effect in patients with transfusion-dependent kidney tumor-related hematuria, four patients aged 61-71 years were successfully treated with RF ablation, with a mean follow up of 12 months. Baseline creatinine levels varied from 2.0 mg/dL to 3.7 mg/dL. All patients had received red blood cell transfusions in the days and hours before RF ablation. No subsequent surgical or interventional procedures were required for management of hematuria. Gross hematuria resolved in 24-48 hours in all four patients. Two of the patients are alive with stable renal function and two died of causes unrelated to treatment. RF ablation may be an effective therapeutic option for transfusion-dependent cancer-related hematuria in patients with renal insufficiency, solitary kidney, or comorbidities, or after failed conventional therapies in patients who are not candidates for surgery.     

Increased renal retention of 99mTc-methylene diphosphonate after nephron-sparing surgery.

Nephron-sparing surgery has become established as an effective treatment for localized renal cell carcinoma when preservation of renal function is necessary. The surgery usually requires temporary renal artery occlusion and may induce ischemic renal damage. In this study, we retrospectively evaluated renal activity on bone scintigraphy after nephron-sparing surgery. METHODS: Eleven patients who underwent nephron-sparing surgery for renal cell carcinoma and had a normal contralateral kidney were studied. A total of 12 bone scintigraphy images with 99mTc-labeled methylene diphosphonate were obtained within 1 y after surgery in these patients to assess skeletal metastasis. Activity in the spared renal parenchyma was compared visually with that in the contralateral normal kidney. RESULTS: The tumor was successfully resected in every patient, and no clinically significant complications occurred. Activity in the spared renal parenchyma was elevated in six of seven examinations performed within 21 d after surgery. In three examinations, the increase in renal activity was heterogeneous, being relatively prominent near the surgical margin. Increased renal activity was not observed on five examinations performed 3 mo or more after surgery. CONCLUSION: Renal retention of bone-seeking agents is elevated in the early period after nephron-sparing surgery, probably as a result of ischemic insult during the surgical procedure. Bone scintigraphy may aid in evaluating the presence and degree of ischemic damage of the spared renal parenchyma.     

Percutaneous transluminal angioplasty vs. surgery for renovascular hypertension

Therapeutic results in 102 hypertensive patients were evaluated after either renal artery percutaneous transluminal angioplasty (PTA) or surgical bypass procedures for renovascular hypertension. A minimum of 6 months of follow-up was accepted to evaluate therapeutic success or failure. Renal angioplasty had a beneficial result in each of 13 patients with fibromuscular dysplasia and in 10 (83%) of 12 patients with atherosclerotic lesions that did not involve the origin of the renal artery. Although surgery was also beneficial in each of six patients with fibromuscular dysplasia, it helped only five of 10 patients with atherosclerosis of the renal artery. Angioplasty results were similar to surgical results for atherosclerotic lesions that involved the origin of the renal artery. Angioplasty was unsuccessful in two cases of neurofibromatosis because of the firm nature of the lesions, where a bypass procedure was successful in one case. Major complications were more common in surgical cases than in angioplasty. PTA is recommended for all renal artery lesions; surgery should be reserved for failed PTA or recurrent renal artery stenosis after PTA.     

Transcatheter Arterial Embolization Using Ethanol in a Dialysis Patient for Contracting Enlarged Polycystic Kidneys

The mass effect of nephromegaly in patients with autosomal dominant polycystic kidney disease may cause pain and symptoms by compressing the alimentary tract, lungs, and heart. Conventional therapies exist to contract enlarged polycystic kidneys including surgical and interventional procedures. A surgical nephrectomy is often difficult to perform in dialysis patients due to the associated risks related to surgery. In contrast, renal transcatheter arterial embolization (TAE) with metallic coils, which is a less invasive interventional procedure, can also be utilized to contract enlarged kidneys in dialysis patients as an effective treatment. However, metallic coils present the possibility of recanalization and cost issues. Thus, we used ethanol instead of coils in renal TAE to resolve these issues. We report a dialysis patient with enlarged polycystic kidneys and poor oral intake due to abdominal distention that was successfully treated by TAE with absolute ethanol.     

小肾癌临床诊疗体会

目的探讨小肾癌的诊断和治疗方法,比较不同手术方法的优缺点。方法分析2000年8月～2007年8月收治的24例小肾癌的临床表现、诊断、治疗及预后并结合有关文献进行讨论。结果24例中全部手术治疗,18例行根治性肾切除术,6例行保留肾单位肾肿瘤切除术,术后均经病理证实。20例获得随访,16例无癌存活,最长已超过7年。结论小肾癌多为B超偶然发现,术前B超、CT、肾动脉造影综合分析明确诊断;手术方式依据具体情况采取根治性切除术（RN）或保留肾单位手术（NSS）;预后主要取决于肿瘤的分期和分级。     

Transcatheter embolisation of iatrogenic renal vascular injuries

Purpose

The aim of our study was to review our experience and long-term follow-up in the treatment of iatrogenic renal vascular injuries using transcatheter embolisation.

Materials and methods

Our retrospective analysis of cases collected in two interventional centres consists of a total of 21 patients who underwent renal arterial embolisation (RAE) for iatrogenic arterial kidney bleeding. Biopsy (n = 4), percutaneous nephrolithotomy (n = 4), nephron-sparing surgery (n = 4), guidewire-induced arterial perforation during coronary angiography or renal stenting (n = 3), percutaneous nephrostomy (n = 3), renal endopyelotomy/pyeloplasty (n = 2) and surgical nephrectomy were the iatrogenic causes. Seven patients presented with haemodynamic instability requiring blood transfusion (33.3 %), the remaining were haemodynamically stable (66.7 %). Diagnostic renal angiography revealed 9 actively bleeding vessels, 6 pseudoaneurysms, 4 arteriovenous fistulas and 1 arterio-calyceal fistula. In one patient selective renal arteriography was negative probably because the bleeding observed at CT angiography was self-limited. Twenty-one embolisation procedures were performed in 20 patients; one patient required a second embolisation 3 h after the first one. Embolisation was performed with microcoils, polyvinyl alcohol particles, embospheres, spongostan emulsion and vascular plug.

Results

The technical success rate was 100 %. The overall clinical success rate was 95 %. Apart from a patient who died due to disseminated intravascular coagulation, no major complications requiring intensive care treatment were encountered during or after the procedures. No patient required emergency surgery or subsequent surgical treatment. No statistically significant differences in eGFR or renal function stage appeared after RAE.

Conclusions

Percutaneous treatment can be proposed as a first-line treatment in iatrogenic renal arterial injuries, resulting in a safe and effective procedure.     

Digital intravenous substraction angiography in the evaluation of reconstructed renal arteries

Digital intravenous subtraction angiography (DISA) was used to evaluate 28 patients who had undergone renal artery reconstruction either as part of a renal transplant procedure or for treatment of renovascular hypertension. Satisfactory visualization of the renal artery was obtained in 26 cases, and the clinical questions were adequately answered in these cases. The findings included a variety of possible outcomes and demonstrate the adequacy of DISA as a means of evaluating the results of renal artery surgery. Technical and anatomic factors affecting the quality of the examination are discussed. The cases also illustrate the critical importance of thorough familiarity with the surgical procedures in general and of mutual discussion between surgeon and radiologist in optimizing the DISA examination in a given patient.     

肾癌患侧肾动脉变异及其对根治性肾切除术影响的MDCTA评价

目的:采用MDCTA技术观察肾癌患者患侧肾动脉变异并评价其对根治性肾切除术操作的影响。方法:对109例临床诊断为肾癌的患者术前行CT三期增强扫描,并对动脉期CTA图像进行后处理,观察并记录肾癌患侧变异肾动脉的发生并及可能影响根治性肾切除术的肾动脉因素。结果:肾癌患侧变异肾动脉的发生率为11.9%(13/109),表现为多支肾动脉84.6%(11/13)和过早分支23.1%(3/13),含混合型1例;副肾下极动脉最常见(71.4%),且其开口位置和走行变异较大,其中右侧副肾下极动脉开口位于主肾动脉下为(29.44±15.13)mm,约50%走行于下腔静脉前,50%走行于下腔静脉后;左侧副肾下极动脉开口位于主肾动脉下方(42.55±0.64)mm。结论:CT多期增强扫描动脉期CTA图像可以充分显示肾癌患侧肾动脉变异情况,术前明确变异血管的存在及走行对根治性肾切除术的操作有重要意义。     

The clinical picture of renal cell carcinoma. The place of diagnostic imaging]

Surgery continues to be the only treatment of proven efficiency for renal cell carcinoma. Chemo- and radiotherapy must be regarded as ineffective. Antagonists of the multiple drug-resistance gene, which is responsible for the chemoresistance of renal cell carcinoma as well as immunotherapy, are new experimental approaches in the treatment of renal cell carcinoma. The broad use of ultrasonography as a screening method has led to an increase in the diagnosis of small, asymptomatic renal tumors. At present, almost 65% of the renal tumors referred for surgery at our institution are asymptomatic. We found parenchyma-sparing surgery to be adequate treatment for many of these tumors. Advanced stages of renal cell carcinoma, on the other hand, can be cured by ultra-radical surgery (e.g., tumor thrombectomy or metastasectomy) in a considerable percentage of patients, as long as diffuse distant metastases are absent. Utilization of a broad range of imaging techniques is mandatory to rule out diffuse dissemination when considering such an operation.     

Arteriovenous fistulas complicating biopsy of renal allografts: treatment of bleeding with superselective embolization

The use of superselective embolization was assessed as a treatment for bleeding from postbiopsy arteriovenous fistulas (AVFs) in renal transplants. AVFs commonly occur after biopsy procedures in renal transplants, but severe bleeding is rare. Transcatheter embolization can be used to control bleeding, but unless it is sufficiently selective, the procedure results in loss of significant amounts of renal parenchyma. During a 4-year period, embolization procedures were attempted in seven patients 30-65 years old. All had AVFs shown on arteriography. Five patients underwent embolization; occlusion occurred only in the branch supplying the AVF. In one patient with three large AVFs, two were found to have occluded the day after embolization was attempted. In another, an AVF occluded when superselective catheter position was achieved but before embolization. Catheter manipulation in these cases may have precipitated occlusion. In five cases, coaxial embolization techniques were used. Embolization materials consisted of coils in three cases: 0.038 in. (0.97 mm) in one case, 0.025 in. (0.64 mm) in one case, 0.018 in. (0.46 mm) in one case; 0.038 in. (0.97 mm) coils and gelatin foam particles in one case; and localized contrast extravasation in one case. Serum creatinine level was measured before and after embolization in all patients, and radionuclide studies were undertaken in three cases. In all patients, bleeding was effectively controlled. None of the patients showed an increase in serum creatinine level after embolization, and in four, significant improvement was seen. Nuclear medicine studies showed no loss of renal function and a dramatic improvement in one patient. No complications due to the procedure were seen. Our experience suggests that superselective embolization with coaxial catheter techniques is an effective method of treating bleeding from postbiopsy AVFs in renal transplants with minimal loss of renal parenchyma.     

Craniofacial cavernous venous malformations: percutaneous sclerotherapy with use of ethanolamine oleate

PURPOSE: To assess the efficacy of percutaneous sclerotherapy with use of ethanolamine oleate for craniofacial cavernous venous malformations. MATERIALS AND METHODS: From 1991 to 2001, sclerotherapy (average of two procedures per patient) was performed in 29 patients (mean age, 22 y; 10 male) with craniofacial venous malformations. Direct puncture venography was performed with use of water-soluble contrast media to delineate the extent of the lesions. CO(2) gas was used as contrast medium in addition to water-soluble contrast media in five patients in whom lesions had large nondependent areas. Coil embolization with a transvenous approach was performed in two patients when the lesions had large draining veins. Then, a mixture of 5% ethanolamine oleate and iodized oil (ratio, 5:1-5:2) was injected manually into the lesions under fluoroscopic guidance to monitor the process. A total of 59 procedures were performed. Clinical follow-up was obtained in 25 of 29 patients. The duration of follow-up ranged from 10 days to 6 years (mean, 8.5 mo). The effectiveness of sclerotherapy was assessed on the basis of clinical, surgical, and radiologic findings. RESULTS: The procedures were effective in 14 of 16 patients who underwent sclerotherapy only. The procedures were beneficial for all nine patients who underwent sclerotherapy and surgery. There was no skin injury or nerve damage. The trismus that appeared in two patients with lesions in the masticator space was treated well by conservative therapy. CONCLUSION: Percutaneous sclerotherapy with use of ethanolamine oleate is a safe and effective treatment of craniofacial cavernous venous malformations. However, renal function was not specifically evaluated after treatment, and therefore occult renal dysfunction cannot be excluded.     

Persistent and recurrent postsurgical varicoceles: venographic anatomy and treatment with N-butyl cyanoacrylate embolization

PURPOSE: To elucidate the mechanism of persistence or recurrence of varicoceles after surgical repair by examining the venographic anatomy, and to review the efficacy of treatment of these patients with n-butyl cyanoacrylate (NBCA) embolization. MATERIALS AND METHODS: From 2001 to 2007, 17 patients with persistent or recurrent varicoceles were studied by retrograde venography 4 months to 18 years after open surgical repair. All patients were then treated with NBCA glue embolization of the entire gonadal vein and the venographically identified duplications and collateral vessels, with three patients undergoing bilateral procedures. Venographic anatomy and clinical success were retrospectively analyzed. RESULTS: The majority of patients (65%) exhibited duplications draining into a single left gonadal vein. Duplications were most frequently found to be confined to the pelvis and inguinal canal. Communication with other retroperitoneal veins, including the renal hilar, lumbar, iliac, and circumaortic renal vein, was relatively uncommon. NBCA embolization effectively treated the main gonadal vein as well as the duplications and communications, with only one patient developing thrombophlebitic complications. CONCLUSIONS: Duplication of the gonadal vein in the pelvic or inguinal region with apparent incomplete ligation or resection is a common finding in patients with persistence or recurrence of varicocele after surgery. NBCA embolization effectively treats these duplicated vessels, resulting in a high rate of clinical success on short-term follow-up.     

Prolonged renal parenchymal retention of 99mTc mercaptoacetyltriglycine after nephron-sparing surgery

OBJECTIVE: Nephron-sparing surgery is a treatment in which a part of a diseased kidney is resected and some parenchyma of the kidney is spared. Impairment of spared renal parenchyma after the surgery may cause prolonged prarenchymal retention in renal scintigraphy with Tc mercaptoacetyltriglycine (Tc-MAG3). The aim of this study was to determine whether or not parenchymal retention of Tc-MAG3 is prolonged after nephron-sparing surgery. METHODS: Twenty-two patients underwent a total of 29 Tc-MAG3 studies within 1 year after nephron-sparing surgery. In 17 patients (23 examinations) who had bilateral kidneys, the presence of diffuse prolongation of parenchymal retention was determined for the operated kidney. In all patients, the presence of regional prolongation around the surgical margin was assessed. RESULTS: Diffuse prolongation was observed in four of 10 examinations performed within 1 month after surgery and in none of 13 examinations performed later than 1 month after surgery. Regional prolongation was shown in 10 of 14 examinations performed within 1 month after surgery and in three of 15 examinations performed later than 1 month after surgery. In five patients who were studied both prior to and later than 1 month after surgery, regional prolongation was noted on the first study. On the second study, regional prolongation was improved and initial renal uptake around the surgical margin was intensified. CONCLUSIONS: Renal parenchymal retention of Tc-MAG3 is frequently prolonged in the early period after nephron-sparing surgery. Renal scintigraphy with Tc-MAG3 may aid in characterizing acute renal damage after nephron-sparing surgery.