Retroperitoneoscopic partial nephrectomy using radiofrequency ablation

Two patients with renal tumors underwent retroperitoneoscopic partial nephrectomy. The renal tumors were initially treated with radiofrequency ablation. This method allowed tumor excision to be achieved without clamping the renal pedicle. Residual renal function was well maintained as determined by enhanced computed tomography scanning and measurement of the serum creatinine level. There were no complications such as vascular damage or collecting system injury. The pathological diagnosis was clear cell carcinoma (pT1) in Patient 1 and was not determined in Patient 2 because of entire ablation. No recurrence has been observed after 3 years and 2 years of follow up, respectively. Radiofrequency ablation was useful for control of local bleeding during retroperitonaoscopic partial nephrectomy.     

Treatment of renal tumors with radiofrequency ablation

BACKGROUND: Radiofrequency (RF) energy has been investigated as a minimally invasive modality for ablating small renal tumors. Recent advances in the application of this technology have improved its safety and effectiveness. MATERIALS AND METHODS: We describe the technology of RF application and review the current delivery systems as applied to renal tumor ablation. We also review relevant animal studies, which have revealed the natural history of ablated renal tissue. Finally, we examine recent human trials with an emphasis on longer-term follow-up, imaging, complications, and successful ablation according to tumor location within the kidney; i.e., central v peripheral. RESULTS: Radiofrequency ablation can be performed safely in a minimally invasive fashion either percutaneously or laparoscopically. Energy delivery varies, and available systems include dry, wet, cooled-tip, and bipolar electrodes. Heat rise and subsequent charring in the tissue adjacent to the electrode is limited by temperature or impedance-based feedback systems. In animal studies, ablation results in complete cell kill, as judged by nicotinamide adenine dinucleotide diaphorase staining. Clinical trials with intermediate follow-up show excellent success rates. Tumors >3 cm and central tumors have a higher recurrence rate after RFA than smaller, more peripheral tumors. CONCLUSIONS: The current literature suggests that RFA is a promising minimally invasive method of treating small renal tumors. Nevertheless, long-term follow-up is still required, and questions remain regarding the optimal delivery system, duration of ablation, and method of surveillance.     

超声引导下射频消融联合乙醇消融与单纯射频消融治疗甲状腺良性囊实性结节的疗效对比

目的 探讨射频消融联合乙醇消融与单纯射频消融对良性囊实性甲状腺结节治疗效果的差异.方法 选取2015年1月-2018年7月就诊于郑州大学第一附属医院甲状腺外科,颈部彩超确认为甲状腺囊实性结节,且结节最大直径≥20 mm,穿刺病理结果为良性,拟行甲状腺射频消融手术的80例患者的病理资料,根据病情及患者意愿,分别行单纯射频...     

Ultrasound-guided percutaneous ablation of a renal mass in a renal allograft

A 50-year-old man underwent magnetic resonance imaging and was found to have an incidental 3.2-cm mass in a renal allograft. Because of the multiple comorbidities associated with renal allograft patients, a minimally invasive option such as percutaneous ablation should be considered. The patient underwent percutaneous ultrasound-guided cryoablation. The final histopathologic examination of the needle biopsy was consistent with an oncocytic neoplasm. The 9-month follow-up contrast-enhanced magnetic resonance imaging scan showed no residual tumor. Long-term follow-up and greater clinical experience are still necessary to confirm the efficacy of cryoablation for allograft lesions.     

Pain after percutaneous radiofrequency ablation of renal tumors

BACKGROUND AND PURPOSE: Most patients have minimal pain after percutaneous radiofrequency ablation (RFA) of a renal tumor. However, anecdotally, there is some variation in the amount of patient discomfort. Our goal was to identify relevant patient factors and characteristics of their renal tumors that may influence pain after percutaneous RF ablation. PATIENTS AND METHODS: We performed a retrospective chart review of 59 sequential patients who received percutaneous RFA between 2001 and 2005 at a single institution. Data on patient age, sex, body mass index (BMI), and narcotic administration in the periprocedural period were available for 46 patients. Preoperative imaging (CT or MRI) was reviewed to determine tumor size and location, as well as the shortest distance of the mass to the body-wall musculature. RESULTS: The distance from the renal mass to the body-wall musculature was significantly correlated with the total narcotics received in the periprocedural period. This measured distance did not correlate with the patient's BMI. No other relations between patient factors or tumor characteristics and peri-procedural narcotic usage were identified. CONCLUSION: Patients whose tumors lie close to their body-wall musculature have greater narcotic requirements in the periprocedural period. Knowledge of this correlation should result in better patient counseling and help anticipate periprocedural analgesia requirements.     

Comparison of renal ablation with cryotherapy, dry radiofrequency, and saline augmented radiofrequency in a porcine model.

BACKGROUND: Needle ablative therapy has recently generated a lot of interest in the urologic community. We compare renal lesions produced in a porcine model using three forms of needle ablative energy: cryoablation (CR), dry radiofrequency (RF), and saline augmented radiofrequency (SARF). STUDY DESIGN: In 10 farm pigs, under ultrasonographic guidance, 40 laparoscopic renal lesions were produced: 825-mm CR lesions were produced with 2.4-mm cryoprobes (Endocare Inc, Irvine, CA), after 1-mL preinfusions of 14.6% saline, 12 SARF lesions were created with 22-gauge needles (2 mL/minute 14.6% saline, 50 W 510 kHz RF for 60 seconds), 12 RF lesions were created with a 2-cm array LeVeen electrode and an RF2000 generator using impedance limited 30 to 60 W double activations (Radiotherapeutics Corp, Mountain View, CA), and 8 RF lesions were produced using 22-gauge needles and double 10 W activations with the RF2000 generator. Eight animals were sacrificed after 1 week for acute pathology. An additional two animals were sacrificed at 8 weeks to provide chronic pathology results for the LeVeen dry RF and SARF modalities. RESULTS: CR produced a regular 18- to 22-mm zone of complete necrosis bordered by a 1.5- to 2.5-mm zone of partial necrosis. Acutely, LeVeen RF and single-needle RF produced lesions 25 to 45 mm and 6 to 10 mm wide, respectively. Acutely, SARF produced irregular cone-shaped lesions 15 to 31 mm wide. Only one of eight acute LeVeen RF lesions showed complete necrosis; none of the four 8-week LeVeen RF lesions displayed complete necrosis. Two of the four 8-week SARF lesions displayed complete necrosis. The remainder of the LeVeen RF, single-needle RF, and SARF lesions showed early, indeterminate tubular damage with relative glomerular sparing and bands of complete necrosis (0.5 to 1.5 mm) and inflammation (0.5 to 2 mm) at the periphery. Only CR could be consistently monitored with laparoscopic ultrasonography. CONCLUSIONS: Renal cryoablation produces well-defined, completely necrotic lesions that can be monitored reliably with ultrasonography. Longer followup may be required to characterize the full extent of renal necrosis produced by RF, but in the short run, none of the RF modalities reliably produced 100% necrosis in all cases.     

腹腔镜下冷循环射频消融治疗肾细胞癌

目的 探讨腹腔镜下冷循环射频消融治疗肾细胞癌的可行性. 方法对12例肾癌患者选择性实施腹腔镜下冷循环射频消融治疗13次.肿瘤位于左肾4例,右肾7例,双肾1例.肿瘤最大径2.1～8.5 cm,其中T1N0M0 11例,T2N0M0 2例.术后采用CT、超声造影定期随访. 结果 平均手术时间(92±24)min,平均出血量(50±2)ml,术中均末输血.未见腹腔镜手术相关并发症.术后6周13个肾癌病灶,完全消融12个、消融不全1个,完全消融率92.3%(12/13).血红蛋白、红细胞沉降率、血肌酐、患侧肾小球滤过率较术前无明显变化(P>0.05).术后3个月10例患者复查CT,病灶完全坏死9例、部分坏死1例.随访时间1～16个月,中位数7.8个月,12例均生存.无局部及远处复发病例. 结论 腹腔镜下冷循环射频消融是一种安全有效治疗肾癌的新方法,比超声引导下射频治疗定位更加精确,可以应用于不适合超声引导下经皮肾穿刺射频消融的病例.     

肾癌射频消融治疗后的影像学评价

射频消融（RFA）已用于肾癌的临床治疗,具有微创、可重复操作、并发症少、有利于保留患者的肾功能等优点。通过影像学检查,可以准确评价肾癌RFA疗效,早期检测是否存在肿瘤残留及复发。本文对CT、MRI及超声在肾癌RFA治疗后疗效评价中的应用进行综述。     

Renoduodenal fistula after renal tumor ablation with radiofrequency

PURPOSE: To report a renoduodenal fistula after renal tumor ablation with radiofrequency (RFA). METHODS: A 1-inch right anterior renal cell carcinoma was subjected to percutaneous RFA under sedation. We used a 14-gauge probe guided by ultrasonographic images in real time. RESULTS: On the fifth day the computerized tomography with double contrasts showed a fistula between the pelvis and the duodenum. CONCLUSIONS: A major concern regarding this approach relates to the anterior renal tumor and the guided images during the procedure. To our knowledge, there has never been any report of renoduodenal fistula after RFA.     

Neuromuscular complications after percutaneous radiofrequency ablation of renal tumors

Neuromuscular complications after percutaneous renal tumor ablation have not been previously reported. In a series of 48 patients undergoing percutaneous ablation, 3 of our patients had neuromuscular complications. One patient developed permanent flank laxity and two had transient paresthesias. Neuromuscular complications are uncommon, but may occur with percutaneous renal ablative surgery.     

'Skipping' is still a problem with radiofrequency ablation of small renal tumours

OBJECTIVE: To evaluate the homogeneity and extent of necrosis obtained with next-generation radiofrequency ablation (RFA) equipment and techniques, as incomplete tumour necrosis, or 'skipping', has been documented after RFA of renal tumours and subsequent partial nephrectomy, but this was assumed to result from insufficient energy deposition with first-generation low-energy generators. PATIENTS AND METHODS: In all, 17 patients with solitary renal tumours of 0.5-1.0 cm beyond the sonographically controlled tumour borders. Target temperatures of 105 degrees C were applied in three cycles for 10-30 min at up to 150 W. Tumours were then removed by laparoscopic partial nephrectomy and specimens evaluated by detailed histology. RESULTS: The mean (range) resected tumour size was 22 (11-40) mm, the mean RFA time was 39 (27-59) min and the mean surgical resection time was 25 (12-45) min. In 13 patients, haemostasis was sufficient to avoid the renal pedicle being clamped. Intraoperative repeated positive margins in one patient required a laparoscopic radical nephrectomy. Thirteen (76%) renal masses showed histologically complete ablation of the entire tumour. Of the four RFA failures, three tumours were >3 cm in diameter, two were highly vascularized and three had a very heterogeneous tissue texture. CONCLUSION: Even with state-of-the-art technology, skipping remains a problem with RFA for small renal masses and renders the technique unreliable.     

Real-time virtual ultrasonographic radiofrequency ablation of renal cell carcinoma

OBJECTIVE

To evaluate the usefulness of real‐time virtual ultrasonography (RVS) as a new navigational tool for percutaneous radiofrequency ablation (RFA) of solid renal cell carcinoma (RCC).

PATIENTS AND METHODS

Ten patients with 13 RCCs were treated with percutaneous RFA using RVS, which displays ultrasonograms and corresponding multiplanar reconstruction images of computed tomography in parallel.

RESULTS

RVS allowed excellent anatomical visualization and precise navigation of RFA for RCC. All patients were treated successfully in one session with percutaneous RVS RFA. There were no significant complications, and none of the patients had a local tumour recurrence during the follow‐up.

CONCLUSION

RVS for RFA of solid RCC is a new and promising alternative imaging method.