Initial Experience with the Use of a Robotic Stapler for Robot-Assisted Donor Nephrectomy.

INTRODUCTION: Since the first description of robot-assisted laparoscopic donor nephrectomy for living donor renal transplantation, additional studies have noted outcomes comparable to traditional laparoscopic surgery. Urologists have embraced the technical advantages of the robotic approach, including improved dissection and more accurate graft preservation. With the advent of robotic stapling, we aim to demonstrate the feasibility of the use of robotic stapling for living-donor nephrectomies. MATERIALS AND METHODS: Ten cases of da Vinci® EndoWrist® Stapler use during robot-assisted donor nephrectomy by a single surgeon are reported. Variables examined included patient anatomy, estimated blood loss (EBL), warm ischemia time (WIT), postoperative complications, and graft function at follow-up. The costs of the laparoscopic and robotic staplers at our institution are reported. RESULTS: One right and nine left nephrectomies were performed by a single surgeon. Eight living donors had a single renal artery and vein, while two had multiple renal arteries and renal veins. A single vascular stapler load (45-mm, white cartridge) was used for vessels in all cases. WIT was <6 minutes in each case, and EBL ranged from 13 to 100 mL. Sufficient length on the renal artery and vein was obtained to execute anastomoses in all cases. Only one patient had postoperative complications that were related to anesthesia. Graft function of recipients and postoperative renal function has been adequate to date. The cost of using the robotic stapler was $705 (EndoWrist Stapler), and the cost of the laparoscopic stapler (Endo GIA™ Stapler; Medtronic, Dublin, Ireland) was $494.06. CONCLUSIONS: The use of robotic stapler is feasible in terms of patient safety, technique, postoperative outcomes, and cost in both left- and right-sided living-donor robotic nephrectomies. Further research is needed to confirm the benefit and safety of EndoWrist stapler use in robotic donor nephrectomies compared to laparoscopic stapler use.

Duplex scan and histologic assessment of acute renal injury in a kidney-kidney crosstalk swine experimental model.

OBJECTIVE: The objective of this study was to identify the effect of two left renal vasculature occlusion strategies on the duplex ultrasound-assessed rheology and histology of the contralateral kidney. METHODS: Pigs were randomly assigned to one of two groups: left renal artery-only clamping (A group, n = 8) or left renal artery and vein clamping (AV group, n = 9). Bilateral renal parenchymal biopsy specimens were taken every 10 minutes for 90 minutes. Duplex ultrasound resistive index (RI) and pulsatility index (PI) were measured. Mixed models with normal distribution and first-order autoregressive correlation structure and generalized estimating equation models were used. Results are presented as adjusted means with standard errors, estimated proportions with standard errors, and line plots with 95% confidence intervals. RESULTS: RI and PI increased in the nonischemic kidney. In A group animals, RI values increased significantly (P < .01) after 30 minutes of ischemia and PI increased significantly (P < .04) from 30 to 60 minutes of ischemia. The number of histologic abnormalities was higher in A group than in AV group biopsy specimens. The percentage of lesions increased significantly after 10 minutes in A group nonischemic kidneys (P < .02) and between 50 and 80 minutes in AV group nonischemic kidneys (P < .01). CONCLUSIONS: Nonischemic kidneys were acutely affected by contralateral ischemia. Their function was more adversely affected by unilateral renal artery occlusion with preserved renal vein patency (A group).

[The use of polymeric Hem-o-lock clips in laparoscopic radical nephrectomy]. / Zastosowanie polimerowych klipsów Hem-o-lock w laparoskopowej nefrektomii radykalnej.

OBJECTIVES: The aim of the study was to evaluate the usefulness and cost-effectiveness of polymeric Hem-o-lock clips during laparoscopic nephrectomy. The intra- and postoperative complications of the operation were assessed too. MATERIAL AND METHODS: From April 2011 through November 2011, 19 laparoscopic radical nephrectomies were performed. A preferred method to secure the renal vein was the use of polymeric Hem-o-lock clips. The renal artery was clipped by titanium clips. In five patients an Endo-GIA stapler was used to secure the renal pedicle. All procedures were carried out using a transperitoneal access. The perioperative data were analyzed retrospectively. RESULTS: No intraoperative complications associated with the use of Hem-o-lock clips were observed. The mean procedure time was 202 min. The average blood loss during the operation was 480 ml. No bleeding in the postoperative period was observed. The mean abdominal drain output was 65 ml per day. The mean time to drain removal was 3 days. The average hospital stay was 5-6 days. CONCLUSIONS: Using the polymeric Hem-o-lock clips is a safe, relatively easy and cheep way to close the renal vein during laparoscopic radical nephrectomy.

Use of cine phase-contrast MRI in the assessment of distal splenorenal shunt function.

Magnetic resonance imaging (MRI) features of a surgical splenorenal shunt in a 28-year-old girl are described. The woman underwent color doppler ultrasonography during follow up for the shunt, which was inconclusive. MR was used to investigate the function of the shunt. Velocity and flow direction in splanchnic vessels and in the shunt were evaluated using cine fast phase-contrast sequences. MR findings could be of help in the evaluation of patients undergoing surgical shunts during follow up.

Vascular clips are safe and a great cost-effective technique for arterial and venous control in laparoscopic nephrectomy: single-center experience with 1834 laparoscopic nephrectomies.

PURPOSE: To evaluate the safety and cost-effectiveness of Hem-o-lok and metallic titanium clips for both renal arterial and venous control in laparoscopic nephrectomies. PATIENTS AND METHODS: All patients who underwent laparoscopic nephrectomy from June 2000 to March 2011 in our center were included. Before July 2005, we used three medium-large titanium clips for safe control of renal vessels. After July 2005, we used two clips for renal artery control (one 10 mm Hem-o-lok clip and one medium-large titanium clip) and two clips for renal vein control (12 mm and 10 mm Hem-o-lok clips) in all cases. To prevent possible complications, we placed vascular clips 2 to 3 mm away from the aortic root of the renal artery underneath lumbar vessels. Episodes of clip failure were defined as intraoperative or postoperative hemorrhage or exploration because of clip failure. RESULTS: This study included 1834 laparoscopic nephrectomies (1423 donor nephrectomies, 214 simple nephrectomies, and 197 radical nephrectomies). All arteries and renal veins were controlled by titanium and Hem-o-lok clips. One complication that was probably related to vascular clips (titanium and Hem-o-lok), however, involved a delayed hemorrhage from a pseudoaneurysm at the aortic root of the renal artery, which was repaired at exploration. No complication was clearly related to vascular clips. Using Hem-o-lok and titanium clips instead of vascular staplers resulted in $670 savings per operation. CONCLUSIONS: Hem-o-lok and metallic vascular clips applied properly by trained surgeons according to published safety measures provide a safe and considerable cost-saving option for vascular control in laparoscopic nephrectomy.

Enhanced surgical imaging: laparoscopic vessel identification and assessment of tissue oxygenation.

BACKGROUND: Inherent to minimally invasive procedures are loss of tactile feedback and loss of three-dimensional assessment. Tasks such as vessel identification and dissection are not trivial for the inexperienced laparoscopic surgeon. Advanced surgical imaging, such as 3-charge-coupled device (3-CCD) image enhancement, can be used to assist with these more challenging tasks and, in addition, offers a method to noninvasively monitor tissue oxygenation during operations. STUDY DESIGN: In this study, 3-CCD image enhancement is used for identification of vessels in 25 laparoscopic donor and partial nephrectomy patients. The algorithm is then applied to two laparoscopic nephrectomy patients involving multiple renal arteries. We also use the 3-CCD camera to qualitatively monitor renal parenchymal oxygenation during 10 laparoscopic donor nephrectomies (LDNs). RESULTS: The mean region of interest (ROI) intensity values obtained for the renal artery and vein (68.40 +/- 8.44 and 45.96 +/- 8.65, respectively) are used to calculate a threshold intensity value (59.00) that allows for objective vessel differentiation. In addition, we examined the renal parenchyma during LDNs. Mean ROI intensity values were calculated for the renal parenchyma at two distinct time points: before vessel stapling (nonischemic) and just before extraction from the abdomen (ischemic). The nonischemic mean ROI intensity values are statistically different from the ischemic mean ROI intensity values (p < 0.05), even with short ischemia times. CONCLUSIONS: We have developed a technique, 3-CCD image enhancement, for identification of vasculature and monitoring of parenchymal oxygenation. This technique requires no additional laparoscopic operating room equipment and has real-time video capability.

Assessment of the kidney tumor vascular supply by two-phase MDCT-angiography.

PURPOSE: Current kidney surgery uses less invasive laparoscopic and nephron-sparring procedures. Thus, perfect imaging of the renal vasculature is essential for surgery planning. The aim of our retrospective study was to evaluate the accuracy of 16-detector-row CT-angiography in assessing the vascular anatomy of the kidney with a tumor. SUBJECTS AND METHODS: Referred for computed tomography (CT) because of a suspected renal tumor, 50 consecutive patients (mean age 58.6 years; range 43-82) were enrolled into our retrospective study. All examinations were performed with 16x0.75 mm collimation after the intravenous application of 80 ml of a non-ionic contrast material. The imaging protocol contained two-phase scanning in the arterial and then in the venous phase. The vascular anatomy of the kidney with tumor was evaluated using volume rendered (VRT) and maximum intensity images (MIP). Findings were compared with the anatomy found during surgery. RESULTS: Forty-seven patients underwent nephrectomy, with an advanced clinical stage (IV) found in the three remaining ones. Correct topography of the renal hilus, including a number of arteries and veins, and the anatomy of their branching, was described in 46 patients. A very small upper polar artery was overlooked in one patient. The accuracy for the only-arterial was 97.9% and only-venous anatomy was 100%. The parasitic vasculature of the tumor was discovered in 10 cases and all of them were confirmed by surgery (100% accuracy). Macroscopic intravenous spread of the tumor was discovered in two cases, but microscopic intravenous invasion was confirmed during histology of the kidney specimens in another two cases, the overall tumor staging accuracy reaching 95.7%. CONCLUSION: Two-phase multidetector CT is a valuable tool for assessing vascular supply of the kidney before surgery due to the tumor and can fully replace catheter-based angiography.

Clinical research of renal vein control using Hem-o-lok clips in laparoscopic nephrectomy.

Control of the renal vein represents a crucial step in laparoscopic nephrectomy. Although endovascular gastrointestinal anastomosis (GIA) staplers have generally been used for renal vein control because of the large diameter of the vessel, Hem-o-lok clips have recently been used for renal artery control. GIA staplers are expensive and can malfunction on rare occasions, resulting in severe complications. We evaluated renal vein control using Hem-o-lok clips (adaptive vascular width 7-16 mm) in laparoscopic nephrectomy. Since April 2004, we have ligated renal arteries using Hem-o-lok clips. From June 2004, this method was applied for renal vein control in 40 laparoscopic nephrectomies. After renal pedicle dissection, renal pedicle ligation was accomplished using extra large (XL) Hem-o-lok clips on both the renal arteries and veins by placing two clips on the patient side and one clip on the specimen side. Ligation times for obtaining renal vein control were compared between XL Hem-o-lok clips and GIA staplers in 40 cases before June 2004. Vascular control using XL Hem-o-lok clips was successful in all 40 cases, without any slipping of clips or uncontrolled bleeding. After renal pedicle dissection, ligation time for achieving renal vein control was 167.0 +/- 48 s (range: 122-295 s) using XL Hem-o-lok clips (mean, three clips) and 68 +/- 24.0 s (range: 54-150 s) using a GIA stapler. XL Hem-o-lok clips allow safe and reliable control of renal veins in laparoscopic nephrectomy. Ligation time is only 100 s longer than using a GIA stapler. In addition, costs are reduced by more than 90% compared to GIA stapling.

Control of the renal artery and vein with the nonabsorbable polymer ligating clip in hand-assisted laparoscopic donor nephrectomy.

BACKGROUND: The large and variable size of the renal vein has prompted most surgeons to select linear stapling devices to secure the vein during laparoscopic donor nephrectomy. Although effective, these stapling devices have a potential for misfire. Use of the nonabsorbable polymer ligating (NPL) clip during laparoscopic donor nephrectomy provides increased graft vessel length compared with the stapling device, and the NPL clip has a locking mechanism which may increase security compared with standard titanium clips. The objective of this study was to evaluate the safety and efficacy of the NPL clip for control of the renal artery and vein during hand-assisted laparoscopic donor nephrectomy (HALDN). METHODS: A retrospective chart review of 50 consecutive HALDN patients was conducted where two parallel NPL clips were used to control both the renal artery and vein. Information collected included demographic data, operative and postoperative data, and complications. RESULTS: Mean donor age was 33.4 years and body mass index was 25.8 kg/m2. Mean operative time was 266.0 min, mean hospital stay was 3.2 days, and mean warm ischemia time was 123.3 seconds. There were no transfusions, open conversions, or complications related to use of the NPL clip. A US 16,300 dollars disposable cost savings was seen during this 1-year period alone. CONCLUSIONS: The NPL clip was 100% safe and effective in controlling the renal artery and vein during HALDN, allowed for additional vessel length, and resulted in a disposable cost savings of US 362 dollars per patient.

Renovascular trauma: risk assessment, surgical management, and outcome.

In an effort to define better the indications for renovascular repair, risk factors for renal loss, and eventual patient outcome, records of 36 patients with 37 renovascular injuries were reviewed. The renal artery alone was injured in nine kidneys, the renal vein alone in 12, and both the main renal vein and artery in six. Segmental vessel injuries alone were noted in ten kidneys. Two patients died before repair could be attempted. Eleven nephrectomies were performed. Vascular repair was attempted in the remaining 24 renal units either as isolated procedures or combined with renal parenchymal repair. Compared to 78 patients with only parenchymal injuries, those with renovascular injuries were more severely injured as assessed by nephrectomy rate, Injury Severity Score, transfusion requirement, number of major complications, and death. Fifteen patients sustained main renal artery injuries of whom six underwent immediate nephrectomy. Nine attempts at repair were performed. Six patients had either persistent thrombosis or preservation of only marginal function. One patient died in the immediate postoperative period of associated injuries. Complete renal preservation was achieved in only two kidneys (14%). Nephrectomy was required for the management of three of 12 main renal vein injuries, but in none of ten patients with segmental vascular injuries.

[Experimental intravascular pressure-volume measurement for assessment of the biomechanical load tolerance of microvascular anastomoses]. / Experimentelle intravasale Druck-Volumen-Messung zur Beurteilung der biomechanischen Belastbarkeit mikrovaskulärer Anastomosen.

To investigate the tolerance of microvascular anastomoses to a mechanical load, we performed experimental intravascular pressure-volume measurements on the abdominal aorta and the renal vein in the rat. In one group the vessels were sectioned and repaired with interrupted sutures, while in the control group no surgical intervention was performed. The pressure studies were all undertaken on the 14th post-operative day. All operated vessels showed a distinct decrease in elasticity. High intravascular pressure was reached with little injection volume, but there was no difference between the two groups with respect to the pressure at which leakage occurred. Leaks were located between the single sutures. In no case was a complete disruption observed at the anastomotic site. Consequently, the strength of microvascular anastomoses depends mostly on the suture material. In the experiments the suture material, the number of interrupted sutures and their thickness did not differ from those used in clinical application. This suggests that on the 14th postoperative day microvascular anastomoses on human vessels are of the same strength as demonstrated by our experimental anastomoses. In our opinion therefore reoperation at the anastomotic site or well controlled physical therapy can be tolerated in the clinical case without any risk of anastomotic disruption at least by the 14th postoperative day.

Assessment of portasystemic shunt patency by estimation of D-xylose excretion.

The D-xylose excretion test appears to be a useful method of monitoring shunt patency after a portasystemic venous anastomsis for portal hypertension. A 5-hour urinary excretion greater than 6 g appears an acceptable indicator that the shunt is patent. A second criterion of patency is an increase of 4 g or more over the result of preoperative tests. If the excretion rate falls in the postoperative period or remains less than 4-2 g/5 h, the anastomosis may be assumed to be occluded.