Renal-tissue damage induced by laparoscopic partial nephrectomy using microwave tissue coagulator

BACKGROUND AND PURPOSE: The microwave coagulator is a useful instrument that enables surgeons to perform partial nephrectomy without vascular clamping. The extent of postoperative thermal damage in surgically spared renal tissue has not been well examined. The present study was conducted to evaluate the tissue damage caused by microwave coagulation in laparoscopic partial nephrectomy (LPN) for small renal tumors. MATERIALS AND METHODS: Seven cases of LPN with a microwave tissue coagulator were entered in the present study. The median tumor diameter was 1.5 cm, and the median size of the resected specimen was 2.2 cm. Postoperative tissue damage was evaluated by contrast-enhanced CT 1 month after surgery. Surgically spared renal-tissue volume and functioning renal-tissue volume were estimated from the images by NIH Image 1.62 software. RESULTS: Postoperative CT revealed unenhanced renal tissue adjacent to the surgical margin. The median estimated volumes of surgically spared and functioning renal tissue were 96.1% (range 74.3%-99.8%) and 88.4% (range 68.0%-92.7%) of preoperative normal renal tissue, respectively. The percentile volume of functioning to surgically spared renal tissue ranged from 89.9% to 96.0% (median 92.8%). CONCLUSIONS: The microwave coagulator enables us to carry out partial nephrectomy without vascular clamping. Although 96% of normal renal tissue was surgically spared, 4% to 10% of this tissue was nonfunctioning as a result of microwave-induced thermal damage.     

Partial nephrectomy for renal cell carcinoma using a microwave tissue coagulator--postoperative recurrence and renal function

Nowadays, partial nephrectomy is often selected for treatment of small renal cell carcinoma (RCC) because T1a RCC shows a favorable prognosis with a 5-year overall-survival rate exceeding 90%. To determine the methodological usefulness and treatment outcome of partial nephrectomy using microwave tissue coagulator (MTC), we evaluated our series of 121 patients (124 kidneys) with T1 RCC who underwent this procedure. Ninety-nine patients were elective and 22 patients were imperative cases. This procedure was indicated for asymptomatic solitary RCC; < or =4 cm in diameter in elective cases or < or =5 cm in imperative cases, expanding outward with a clear capsule, and showing neither renal pelvis nor renal sinus invasion. The median operation time was 150 minutes and the median blood loss was 217 ml. Eight patients needed transfusion, and conservative therapy cured 4 patients of postoperative urine leakage successfully. Three patients underwent early secondary nephrectomy due to multiple RCCs, invasive spindle cell carcinoma, or prolongation of urine leakage. No significant deterioration of renal function by creatinine clearance (Ccr) was observed, and postoperative Ccr could be precisely predicted from preoperative serum creatinine value and the renal parenchymal volume estimated with 3-dimensinal image reconstruction. Five-year overall-survival rate was 91% at the mean follow-up of up to 37.9 months and 107 patients were alive without disease. One patient showed local recurrence 2 years later and underwent radical nephrectomy. We believe that non-ischemic partial nephrectmy using MTC is a simple and reliable nephron-sparing surgery for small RCC in respect of postoperative recurrence and preservation of renal function.     

Non-ischemic partial nephrectomy using microwave tissue coagulator

PURPOSE: The indications and the safety of non-ischemic partial nephrectomy using a microwave tissue coagulator were studied. MATERIALS AND METHODS: Non-ischemic partial nephrectomy was performed on 17 kidneys of 16 patients using a microwave tissue coagulator. The diagnosis was renal tumor and renal stones in eleven and five patients, respectively. Renal tumors were less than 4 centimeters in diameter, while the stones were associated with a caliceal diverticulum or secondary cortical atrophy. Excision of the tumors was done via the retroperitoneal approach through an oblique lumbar incision. The needle of the microwave tissue coagulator was inserted around the tumor (stone) 10 to 20 times, and the coagulator was activated. Then the tumor (stone) was excised with a sharp knife or scissors. Patients were encouraged to walk on the first postoperative day. RESULTS: Vascular clamping was necessary in one patient to reduce bleeding. Nephrectomy was done after partial nephrectomy in one patient because it was difficult to close the urinary collecting system after it was widely exposed. Although urine leakage was seen postoperatively in two patients, it ceased spontaneously at 14 and 23 days after surgery. Postoperative complications developed in one of seven patients (14%) with protruding renal tumor, in three of five patients (60%) with non-protruding renal tumor and in two patients with renal stone. Allogenic or autologous blood transfusion was not necessary, nor was any bleeding noticed post-operatively. In one patient, atrophy of the renal parenchyma occurred gradually after surgery and function was eventually lost. However, renal function was well preserved and recurrence of the problem was not observed in the other 15 patients, excluding one who died of esophageal cancer. CONCLUSIONS: The microwave tissue coagulator is a useful surgical instrument for non-ischemic partial nephrectomy, not only in patients with renal tumors but also in patients with complicated kidney stones. However, non-protruding renal tumor in a patient with solitary kidney should be avoided for this surgery. Thermal injury to the renal parenchyma or large vessels should be avoided and urine leakage from the collecting system should be meticulously treated during the operation.     

Partial nephrectomy using a microwave tissue coagulator for bilateral renal cell carcinomas: a case report

We report a case of bilateral renal cell carcinomas in a 56-year-old male treated by partial nephrectomy at the same time using a microwave tissue coagulator technique. The patient did not need dialysis after the operation because we did not need to sacrifice the artery feeding to normal renal tissue during the operation. This technique has advantages of nephron sparing without occlusion of the renal artery, and decreased operation time and blood loss.     

Retroperitoneoscopic partial nephrectomy by using microwave tissue coagulation

Partial nephrectomy is widely accepted as a treatment for small renal cell carcinoma. However, the laparoscopic approach has not yet been considered as a standard procedure. We reviewed our 13 retroperitoneoscopic partial nephrectomies and 11 conventional open partial nephrectomies. We have used microwave tissue coagulation for retroperitoneoscopic surgery without renal pedicle clamping between December 1999 and May 2003. The mean operating time for the retroperitoneoscopic group was not significantly longer than that for conventional open surgery group (183 minutes vs 194 minutes). However, the mean blood loss for the retroperitoneoscopic group was less than that for the open group (143 ml vs 512 ml). Histologic evaluation revealed renal cell carcinoma in 10 patients, angiomyolipoma in 2 patients, and lymphoangiomyomatosis in one patient for retroperitoneoscopic group and renal cell carcinoma in 11 patients for the conventional open surgery group. In addition, when compared with the historical control that had undergone conventional partial nephrectomy, laparoscopic cases had significantly shorter postoperative times to oral intake, ambulance, and discharge from hospital. Bowel injury, massive bleeding, urine leakage, and atelectasis occurred in one case each in retroperitoneoscopic surgery. Retroperitoneoscopic surgery in the case of massive bleeding was converted to open surgery. On the other hand, urine leakage and postoperative hemorrhage occurred in one case each in conventional open surgery. Retroperitoneoscopic partial nephrectomy by using microwave tissue coagulation is a useful and less invasive method, whereas this procedure is more challenging than open partial nephrectomy in terms of complications.     

Partial laparoscopic nephrectomy using monopolar saline-coupled radiofrequency device: animal model and tissue effect characterization

BACKGROUND AND PURPOSE: The optimal surgical tool for laparoscopic partial nephrectomy (LPN) would permit resection of lesions that penetrate relatively deeply and achieve hemostasis while allowing accurate viewing of the margins of the lesion, identification of the collecting system, control of both arteries and veins, and sealing of the collecting system. We hypothesized that the TissueLink Floating Ball (TissueLink, Inc.) might provide a simple, "pure" method of LPN. MATERIALS AND METHODS: Ten adult female pigs (30-50 kg) underwent LPN of the left kidney with the TissueLink operating at 70 to 80 W as the sole means of hemostasis. Operative time, estimated blood loss (EBL), and specimen weight and characteristics, were recorded. On postoperative day 7, an intravenous urogram was carried out, and an open partial nephrectomy and surface treatment were performed on the other side with the TissueLink and intraparenchymal temperature monitoring. RESULTS: All LPNs were performed without complications with an average operating time of 148 minutes and a mean estimated blood loss of 49 mL. The urograms performed at postoperative day 7 demonstrated prompt excretion and no evidence of urinary extravasation or hydronephrosis. At harvest, all eight kidneys in which the collecting system had been entered showed evidence of localized urine leak. No evidence of retroperitoneal hematoma was noted, and all renal arteries and veins were patent and with good flow. The resected edge showed a gross 2 to 3 mm of flat, whitish discoloration and a well-demarcated edge. During the open partial nephrectomy, significant temperature variations were noted according to the distance from the point of application of the TissueLink. Pathologic examination of the acute specimens demonstrated altered cytoplasmic and nuclear staining in tubules extending approximately 6 to 8 mm from the treated surface. In contrast, the kidney that had been left in situ after LPN demonstrated overt cortical necrosis (coagulated necrosis), bordered by cortical scarring with apparent dystrophic calcifications at the resection edge from the previous partial nephrectomy. Tubular atrophy was obvious, with interstitial fibrosis and interstitial inflammation. A well-demarcated zone of several millimeters of tissue was evident on gross examination. CONCLUSIONS: The saline-cooled monopolar radiofrequency dissector (TissueLink) is a valuable adjunct for LPN. The device provided excellent hemostatic control with resection of as much as 40% of the renal parenchyma. Our initial observations of the device in the laboratory and in clinical use led us to develop a successful technique for its use for deep parenchymal resection, which is described in detail.     

Posterior retroperitoneoscopic partial nephrectomy using microwave tissue coagulator for small renal tumors

BACKGROUND AND PURPOSE: Laparoscopic partial nephrectomy remains surgically challenging because of the potential for excessive blood loss, infection, and the development of urinary fistulas. In addition, posterior retroperitoneoscopic partial nephrectomy is not popular because of the limited space for surgical manipulation. We evaluated the usefulness of a microwave tissue coagulator in posterior retroperitoneoscopic partial nephrectomy for small posterior renal tumor. PATIENTS AND METHODS: Posterior retroperitoneoscopic partial nephrectomy was performed without renal pedicle clamping using a microwave tissue coagulator in six patients with small posterior renal tumors. RESULTS: The mean operative time was 136 minutes (range 78-180 minutes), and the blood loss was <20 mL. No serious operative complications occurred, and there was no significant deterioration of renal function. CONCLUSION: Posterior retroperitoneoscopic partial nephrectomy using a microwave tissue coagulator can be a safe and less invasive method for the treatment of small posterior renal tumors.     

Impact of microwave tissue coagulation during laparoscopic partial nephrectomy on postoperative renal function

Laparoscopic partial nephrectomy for small renal tumors has been performed with increasing frequency over the past few years. We prospectively evaluated preoperative and postoperative differential renal function in patients with functioning contralateral kidneys who underwent laparoscopic partial nephrectomy using a microwave tissue coagulator without hilar clamping. Seven patients (five men and two women) in this prospective protocol underwent laparoscopic partial nephrectomy for exophytic tumors using a microwave tissue coagulator when the tumor was 2 cm or less in diameter. Renal scanning with ⁹⁹technetium-labeled diethylenetetraminepentaacetic-acid scan was performed preoperatively and postoperatively at 7 days and 6 months after surgery in all patients. The mean tumor size and surgical duration were 17.0 ± 2.3 mm and 161.1 ± 20.5 min, respectively. Intraoperative blood loss was 35.6 ± 40.7 ml. The preoperative glomerular filtration rate (GFR) and differential split renal function (SF) in the affected kidney were 45.7 ± 12.8 ml/min and 50.5 ± 3.3%, respectively. On postoperative day 7 and at 6 months, GFR and SF in the affected kidney were 36.2 ± 9.0 and 36.8 ± 10.9 ml/min and 44.3 ± 4.1 and 45.0 ± 5.1%, respectively. No postoperative complications occurred. Laparoscopic nonischemic partial nephrectomy using a microwave tissue coagulator has the advantage of technical ease and adequate hemostasis. However, its indication should be restricted to small exophytic renal tumors due to the expected collateral damage causing renal impairment.     

手助腹腔镜与开放手术活体供肾切取术的临床研究

目的比较手助腹腔镜活体供肾切取术（HLDN）和开放手术活体供肾切取术（ODN）的临床疗效,观察术后受者移植肾近期存活情况。方法回顾性分析中南大学湘雅三医院移植中心2004年1月至2013年11月完成的341例亲属活体肾移植供、受者资料。根据供者手术方式的不同,将其分为HLDN组（103例）和ODN组（238例）。比较两组受者手术时长、切口长度、供肾热缺血时间、肾动脉长度、肾静脉长度、术中失血量、围手术期芬太尼用量、术后非甾体抗炎药（NSAIDs）用量和术后恢复劳动天数。术后48h使用视觉模拟评分（VAS）法评估两组供者疼痛程度。术后随访供、受者恢复情况,并于术后7d、1个月复查受者肾功能。连续变量采用t检验进行比较,分类变量采用Fisher确切概率法进行比较。结果HLDN组和ODN组供者切口长度分别为（6．0±0．4）cm和（13．5±1．0）cm,术中失血量分别为（45±12）mL和（151±24）mL,差异均有统计学意义（t=73．56和42．56,P均〈0．05）。两组手术时长、供肾热缺血时间、肾动脉长度、肾静脉长度相比,差异均无统计学意义（t=1．39,1．70,0．00和1．85,P均〉0．05）。103例HLDN组供者中有102例顺利完成手术,1例主动中转开放,术后发生肺部感染1例,无术后切口感染及其他严重并发症。238例ODN组供者均成功完成手术,术后切口感染1例、脂肪液化2例,术后出血通过外科止血2例,无其他手术相关并发症。HLDN组和ODN组供者术后48hVAS分别为（2．3±0．6）分和（3．9±0．9）分,围手术期芬太尼用量分别为（1．7±0．2）mg和（1．9±0．2）mg,术后NSAIDs用量分别为（22±33）mg和（47±42）mg,术后恢复劳动天数分别为（23±10）d和（44±15）d,差异均有统计学意义（t=16．52,8．48,5．37和13．00,P均〈0．05）。两组供者术后7d、1个月血清肌酐水平相比,?     

Retroperitoneal laparoscopic wedge resection for small renal tumor using microwave tissue coagulator

A patient with a small renal tumor underwent a successful retroperitoneal laparoscopic wedge resection using a microwave tissue coagulator without renal pedicle clamping or surface cooling. There were no postoperative complications, and renal function was well preserved. This minimally invasive procedure may be useful for treating small renal tumors.     

Laparoscopic partial nephrectomy using microwave tissue coagulator for small renal tumors: usefulness and complications

OBJECTIVES: We evaluated the usefulness and complications of laparoscopic partial nephrectomy for small renal tumors using a microwave tissue coagulator without renal pedicle clamping. METHODS: Between September 1999 and March 2003, 19 patients with small renal tumors 11 to 45 mm in diameter underwent laparoscopic partial nephrectomy without renal ischemia. RESULTS: Six and 13 patients were treated by the transperitoneal and retroperitoneal approaches, respectively. Excluding a case with open conversion due to dense perirenal adhesions, 18 patients successfully underwent laparoscopic procedures. The mean operative time was 240 minutes with minimal blood loss in 14 patients and 100 to 400 ml in 4. In a patient, frozen sections revealed a positive surgical margin and additional resection was performed. Postoperative complications included extended urine leakage for 14 days, arteriovenous fistula and almost total loss of renal function, respectively, in a patient. With the median follow-up of 19 months, no patients showed local recurrence or distant metastasis by CT scan. CONCLUSIONS: Laparoscopic non-ischemic partial nephrectomy using a microwave tissue coagulator may be useful for treating small renal tumors because it does not require advanced laparoscopic skill. However, the indication of this procedure should be highly selective in order to minimize serious complications secondary to unexpected collateral damage to surrounding structures.     

Application of microwave tissue coagulation in partial nephrectomy

Microwave tissue coagulation was used during partial nephrectomy in 10 mongrel dogs, without clamping the renal artery. There were no major complications, such as retroperitoneal hematoma, abscess formation, or macroscopic infarction of the kidney tissue related to this new procedure. The advantages of microwave coagulation are reduced blood loss, shorter operative time, and minimal risk of vascular injury.     

Partial nephrectomy for renal tumors using selective parenchymal clamping

Purpose To describe our experience with partial nephrectomy using selective parenchymal clamping for the treatment of renal tumors. Patients and methods Between 2003 and 2005, seven patients with solid renal tumors underwent partial nephrectomy with selective parenchymal clamping at our Institution. In five, the tumor was in the right kidney and in two the tumor was in the left. Only one patient had a tumor within a solitary kidney. The tumor was located in the upper pole in 2 patients and in the lower pole in 5. Partial nephrectomy was performed with the DeBakey aortic clamp without occlusion of renal vessels. Results Mean operative time was 236 min (range 175–298 min). Mean intraoperative blood loss was 485 ml with only one patient requiring blood transfusion. There were no major complications. Mean preoperative serum creatinine level was 0.74 mg/dl (range 0.58–1.26 mg/dl) and mean postoperative serum creatinine level was 0.81 mg/dl (range 0.69–1.21 mg/dl) with no patient requiring dialysis. Mean hospital postoperative stay was 5 days (range 4–7 days). Mean tumor size was 2.9 cm (range 1.3–4.0 cm). Pathologic analysis detected renal cell carcinoma in 5 patients, angiomyolipoma in 1 and fibrosis with chronic hemorrhage in 1, all with negative surgical margins. After a mean follow-up of 18 months (range 3–32 months), all patients are free of disease recurrence. Conclusion Partial nephrectomy with selective parenchymal clamping allows resection of solid masses without damage to normal renal tissue, avoids the risk of renal failure and offers an excellent local cancer control.     

Partial nephrectomy for tumour

Thirty-three cases of malignant renal tumour removed by partial nephrectomy are discussed. The indications of this conservative therapy as well as the surgical technique, the results obtained, especially survivals beyond 10 years, as well as the period of time after which the neoplasic disease can be considered as cured are presented.     

Partial nephrectomy using a new dissecting instrument

The kidney is made of friable parenchyma with flexible blood vessels and collecting system structures. A dissecting clamp with interlacing blunt teeth was designed that, by repeated action of closing and opening over the renal parenchyma, crushes and dissects away the friable tissue, leaving the blood vessels and collecting system structures intact. Thus, individual ligation of blood vessels and collecting system structures can be performed at the line of resection. We report our experience in 10 dogs and 1 patient in whom partial nephrectomy was performed with this instrument.