Clinicopathologic analysis of renal cell carcinoma containing Intratumoral fat with and without osseous metaplasia

BACKGROUND

There is minimal information regarding the prevalence of intratumoral adipose in renal cell carcinoma (RCC), and no study has assessed the impact of intratumoral adipose on the preoperative imaging diagnosis. The aim of this study was to investigate the prevalence and histopathologic characteristics of entrapped adipose with or without osseous metaplasia in RCC nephrectomy specimens and to determine if this finding impacted the preoperative imaging interpretation.

METHODS

704 RCC specimens were prospectively evaluated for entrapped adipose and osseous metaplasia (423 partial nephrectomies, 281 total nephrectomies; 327 pT1a, 377 ≥ pT1b; 510 clear cell, 119 papillary, 30 chromophobe, 22 clear cell papillary, 23 other). Imaging reports were obtained, and the presence of intratumoral fat or calcification and the radiologic diagnostic impression were recorded.

RESULTS

3% (n = 21) contained microscopically identified intratumoral adipose, with a similar frequency in the main histologic subtypes (p = 0.76). Mean metaplastic deposit size was 0.4 cm, mean deposit to capsule distance 0.2 cm, and 29% involved the tumor capsule. Histologically identified adipose was infrequently noted via imaging (13%), and only 1 case with histologically identified metaplasia had a radiologic diagnostic differential of angiomyolipoma (1/704, 0.1%).

CONCLUSION

While intratumoral adipose and/or osseous metaplasia can be observed within RCC, it is extremely rare for the radiologic diagnostic impression to have been confounded by histologically identified entrapped adipose. Awareness that metaplastic deposits are usually near the tumor capsule and may be minute could help prevent errors in diagnosis or staging.

Holmium-YAG laser: impact of pulse energy and frequency on local fluid temperature in an in-vitro obstructed kidney calyx model

During laser lithotripsy, energy is transmitted to both the stone and the surrounding fluid. As the energy is delivered, the temperature will rise. Temperatures ≥60  °  C can cause protein denaturation. The objective of this study is to determine the time it takes from body temperature (37°C) to 60°C at various laser power settings. A Flexiva TracTip 200 optical fiber was submerged alongside a negative temperature coefficient-type thermistor in 4 mL of saline in a glass test tube. A Lumenis VersaPulse Powersuite 100-W holmium:yttrium aluminum garnet laser was activated at 0.2- to 1.5-J pulse energies, 6- to 50-Hz frequencies, and 2- to 22.5-W average power. Temperature readings were recorded every second from 37°C until 60°C. Time and heating rate were measured. The procedure was repeated three times for each setting. Average time from 37°C to 60°C for settings (1) 0.2 J/50 Hz, (2) 0.6 J/6 Hz, (3) 1 J/10 Hz, and (4) 1.5 J/10 Hz was 60.3, 172.7, 58, and 43.3 s, respectively. Time from 37°C to 60°C decreased as frequency increased for every given pulse energy. Average heating rate increased proportionally to power from 0.06°C/s at 2 W to 0.74°C/s at 22.5 W. During laser lithotripsy, there is a rapid increase in the temperature of its surrounding fluid and temperatures ≥60  °  C may be reached. This could have local tissue effects and some caution with higher power settings should be employed especially where irrigation is limited. Further studies incorporating irrigation and live tissue models may aid to further define the risks.

Perinephric Hematoma and Hemorrhagic Shock as a Rare Presentation for an Acutely Obstructive Ureteral Stone with Forniceal Rupture: A Case Report

Background: Spontaneous perinephric hematoma (SPH) secondary to a forniceal rupture as the first presenting sign for an obstructive ureteral stone in a patient without history of urolithiasis has not been described previously.

Case presentation: We report a 70-year-old Caucasian male patient who presented to our emergency room with fever, altered mental status, and left flank pain. He had a temperature of 103.3°F, tachycardia, but stable blood pressure. He had left flank tenderness. A computed tomography scan of the abdomen/pelvis with intravenous contrast revealed an intracapsular hematoma (13.3 × 10.0 × 6.4 cm) with an active bleeding and a 1.1 cm left proximal ureteral stone. The patient became quickly hemodynamically unstable and was taken for emergent exploratory laparotomy and left nephrectomy. An active bleeding was encountered secondary to a (2.4 × 2.0 cm) lateral capsular defect in the kidney.

Conclusion: Hemorrhagic/septic shock as a presenting sign for an obstructive ureteral stone may require an emergent nephrectomy in a hemodynamically unstable patient.

Robotic instrument insulation failure: initial report of a potential source of patient injury

OBJECTIVES

To report our experience with failures in the accessory tip covers that insulate the monopolar robotic cautery scissor instruments and the patient injuries that have resulted. Currently, there is no data in the literature regarding the failure rate of robotic instruments or their accessory components.

METHODS

All robotic surgeries performed at our institution were recorded from July 2008 to January 2009. Instrument tip cover failures were recorded at the time of failure regardless of whether a patient complication occurred. Failure was identified by the arching of the electrical current from the insulated portion of the monopolar scissors or by an intraoperative injury.

RESULTS

Four-hundred fifty-four robotic procedures were recorded. A total of 12 accessory tip cover failures were discovered, demonstrating a failure rate of 2.6%, with a patient complication rate of 0.6% (25% of all failures).

CONCLUSIONS

Failure in robotic accessory tip covers can lead to patient complications. The cause for failure can be attributed to a variety of electrical and mechanical causes. All centers and surgeons performing robotic surgery should be aware of the potential for this problem to occur, and the possible interventions that may reduce tip cover failure.

Bovine serum albumin glutaraldehyde for completely sutureless laparoscopic heminephrectomy in a survival porcine model

INTRODUCTION

Laparoscopic partial nephrectomy (LPN) has not received widespread clinical application because of its technical challenge. Bovine serum albumin glutaraldehyde (BSAG) is a hemostatic agent that is independent of the clotting cascade. We evaluated the use of BSAG as the sole agent for parenchymal and collecting system closure during LPN in a survival porcine model.

METHODS

Eighteen pigs underwent hilar clamping and LPN by longitudinal excision of the lateral one-third of the right kidney. The opened collecting system was covered with oxidized cellulose to prevent BSAG seepage into the urinary tract. BSAG was allowed to set for 10 or 5 minutes. Twelve animals underwent survival LPN BSAG only closure; six control pigs were acutely studied using saline. Urinary extravasation was evaluated by injection of furosemide and indigo carmine, and then evaluating the renal surface and bladder catheter drainage for dye. A subjective bleeding score was assigned after hilum unclamping. At 6 weeks, BSAG kidneys were harvested for burst pressure testing and histopathological analysis.

RESULTS

All 12 pigs survived for 6 weeks. No pigs had urinary extravasation. Mean percentage of kidney removed by weight was 19%. Mean warm ischemia time was 29 minutes. Five pigs required a second BSAG application to achieve a bleeding score of 0. Mean arterial and collecting system burst pressures were 301.8 and 322.4 mm Hg, respectively. Mean postoperative creatinine increase was 0.07 mg/dL.

CONCLUSION

BSAG for completely sutureless LPN in a survival porcine model was feasible.

Evaluation of the outcomes of electrosurgical induced bowel injury treated with tissue glue/sealant versus sutured repair in a rabbit model

INTRODUCTION

Bowel injury is an uncommon, although potentially devastating, intraoperative laparoscopic complication. Questions have been raised about the possible use of a tissue adhesive to repair injured bowel. We compared glued repair and sutured repair of both large bowel (LB) and small bowel (SB) electrosurgical injuries in a rabbit model.

METHODS

Pneumoperitoneum was obtained, and four laparoscopic ports were placed in each of 48 New Zealand rabbits. The hook electrode was used in a specified manner to create an equal number of uniform full-thickness injuries to either the SB or the LB. Laparoscopic repair was performed with a 3-0 silk Lembert suture (LS), fibrin glue (FG), or BioGlue (BG), or repair was not performed (i.e., no repair, NR); the animals were monitored for 3 weeks. Adverse clinical outcomes and findings at laparotomy were recorded. Pathologic assessment included an objective scaled evaluation of the intensity of the inflammatory response and degree of healing.

RESULTS

In the SB injury group, deteriorating clinical condition necessitated early euthanasia in one animal repaired with FG, one animal repaired with BG, and two animals with NR. LS repair animals had no adverse clinical outcomes. The LB injury group had no adverse clinical outcomes regardless of the method of repair, including the control group. Of the animals that survived for 3 weeks, the animals repaired with BG had more intraabdominal adhesions (100%) than LS (33%), FG (55%), and NR (50%) (p = 0.001). The pathologic assessment revealed that BG induced a more intense inflammatory response (p < 0.05).

CONCLUSION

In the rabbit, suture repair of an electrosurgical SB injury appears to have improved outcomes when compared with a glued repair. In contrast, LB injury responded well to any form of treatment. The data suggest that suture is superior to biological glues when dealing with a laparoscopic electrosurgical bowel injury.

The UCI Seldinger technique for percutaneous renal cryoablation: protecting the tract and achieving hemostasis

PURPOSE

To describe our Seldinger technique of percutaneous renal cryoablation that was devised to facilitate renal biopsy, cryoprobe placement, and instillation of adjunctive hemostatics while protecting surrounding tissues from cryoinjury.

PATIENTS AND METHODS

This approach was used to manage 13 renal masses in 12 adult patients. Under CT-fluoroscopic guidance, an access needle was inserted to abut the surface of the tumor, followed by an Amplatz super-stiff guidewire and a customized coaxial catheter system, which was used as a conduit for needle biopsy, cryoprobe insertion, and FloSeal instillation. In addition, a porcine model was used to compare the temperature readings adjacent to the sheathed and the unsheathed cryoprobe during percutaneous renal cryoablation.

RESULTS

In all patients, the use of this access approach was accomplished without incident. Two patients needed blood transfusions. No patient had significant skin, muscle, or nerve debility. At a mean follow-up of 11 months, none had evidence of persistent disease on CT or MRI contrast imaging. In the porcine model, the customized sheath protected the surrounding tissues from reaching temperatures below 5 degrees C while temperatures down to -15 degrees C were obtained when no insulating sheath was used.

CONCLUSIONS

A modified Seldinger technique enabled us to perform percutaneous renal cryotherapy through a single access channel, which facilitated access for biopsy, cryoprobe placement, and instillation of hemostatic agents. This approach may provide a protective barrier against cryogenic damage to neighboring tissues and could theoretically help minimize the chance of tract seeding.

Pelvic lymph node dissection and outcome of robot-assisted radical cystectomy for bladder carcinoma

INTRODUCTION

Pelvic lymph node dissection (PLND) at the time of radical cystectomy for urothelial carcinoma of the bladder is critical for accurate staging and may improve oncologic outcomes. Minimally invasive approaches have been criticized for limiting the extent of the PLND. We reviewed our experience with PLND and its perioperative outcomes with robot-assisted laparoscopic radical cystectomy (RARC).

METHODS

Data were collected prospectively from 50 patients scheduled for RARC. Included in the analysis were patients who had RARC and a standard PLND. The entire extirpative portion of the procedure was performed using the da Vinci Robot (Intuitive Surgical, Sunnyvale, CA, USA).

RESULTS

A total of 41 patients were included in the study: 30 men and 11 women with a mean age of 69.7 years (range 49-85) and a mean body mass index of 26.9 (range 19.5-43.7). The median total operative time was 497.77 min (320-805). The mean estimated blood loss was 253.66 ml (range 50-700). The transfusion rate was 44% (18 out of 41) ranging from 0 to 4 units (median 0 units of blood). The mean total number of lymph nodes retrieved was 25.07 (range 4-68). Nodal metastases were seen in 14.63% (6/41). Rate of positive surgical margin was 4.87% (2/41). The median length of hospital stay was 8 days (5-37). The median duration of nasogastric tube, time to ambulation, first clear liquid intake, passage of colonic gas, time to bowel movement, and start of solid food intake were 1 (0-5), 2 (1-7), 3 (2-10), 4 (1-6), 5 (2-11) and 6 days (3-24), respectively.

CONCLUSION

An adequate PLND, comparable with that recommended for open surgery, can be performed safely with robot assistance. The perioperative outcomes were likewise comparable with that of the gold standard, open cystectomy.

Retroperitoneal transdiaphragmatic robotic-assisted laparoscopic resection of a left thoracolumbar neurofibroma

OBJECTIVE

Robotic technology has been used in a variety of surgical procedures for its 3D magnification and precision. Minimally invasive techniques have already become common in neurosurgery; however, robotic-assisted procedures in neurosurgery are still a relatively new frontier. This report describes the first use of robotic technology to resect a left thoracolumbar neurofibroma.

CASE REPORT

A 19-year-old male with a family history of neurofibromatosis was diagnosed with a suspected 3-cm x 4-cm neurofibroma in the T12-L1 left paraspinal area. His only complaint was back pain requiring narcotic analgesics. He had no other findings on physical examination or laboratory/radiologic workup.

METHODS

After consulting urologic robotic surgeons, it was agreed to use the da Vinci robot (Intuitive Surgical, Sunnyvale, CA) for the resection of this mass. Following retroperitoneal laparoscopic access, the urologic surgeons opened the diaphragm and began the initial mobilization of the mass laparoscopically. The robot was docked, and the neurosurgeon operated the robot at the console to resect the mass from its nerve origin. There were no complications, and the mass, a confirmed neurofibroma, was completely removed. The patient was discharged on postoperative day 2; his back pain resolved, requiring no analgesia by the end of the first postoperative week.

CONCLUSION

This case provides early evidence that robotic assistance can be successfully used for the resection of a paraspinal neurofibroma.

Long-term impact of a robot assisted laparoscopic prostatectomy mini fellowship training program on postgraduate urological practice patterns

PURPOSE

Robot assisted laparoscopic prostatectomy has stimulated a great deal of interest among urologists. We evaluated whether a mini fellowship for robot assisted laparoscopic prostatectomy would enable postgraduate urologists to incorporate this new procedure into clinical practice.

MATERIALS AND METHODS

From July 2003 to July 2006, 47 urologists participated in the robot assisted laparoscopic prostatectomy mini fellowship program. The 5-day course had a 1:2 faculty-to-attendee ratio. The curriculum included lectures, tutorials, surgical case observation, and inanimate, animate and cadaveric robotic skill training. Questionnaires assessing practice patterns 1, 2 and 3 years after the mini fellowship program were analyzed.

RESULTS

One, 2 and 3 years after the program the response rate to the questionnaires was 89% (42 of 47 participants), 91% (32 of 35) and 88% (21 of 24), respectively. The percent of participants performing robot assisted laparoscopic prostatectomy in years 1 to 3 after the mini fellowship was 78% (33 of 42), 78% (25 of 32) and 86% (18 of 21), respectively. Among the surgeons performing the procedure there was a progressive increase in the number of cases each year with increasing time since the mini fellowship training. In the 3 attendees not performing the procedure 3 years after the mini fellowship training the reasons were lack of a robot, other partners performing it and a feeling of insufficient training to incorporate the procedure into clinical practice in 1 each. One, 2 and 3 years following the mini fellowship training program 83%, 84% and 90% of partnered attendees were performing robot assisted laparoscopic prostatectomy, while only 67%, 56% and 78% of solo attendees, respectively, were performing it at the same followup years.

CONCLUSIONS

An intensive, dedicated 5-day educational course focused on learning robot assisted laparoscopic prostatectomy enabled most participants to successfully incorporate and maintain this procedure in clinical practice in the short term and long term.

Bone marrow stem cells for urologic tissue engineering

OBJECTIVES

Experiments in rats and dogs have demonstrated the potential of bone marrow-derived mesenchymal stem cells (MSCs) for urinary tract tissue engineering. However, the small graft size in rats and a failure to identify the MSCs in engineered tissues made it difficult to assess the true potential of these cells. Our goals were to characterize MSCs from pigs, determine their ability to differentiate into smooth muscle cells (SMCs) and use them in an autologous augmentation cystoplasty.

METHODS

MSCs were isolated from pigs and analyzed for common markers of MSCs by flow cytometry. SMC differentiation was determined by immunoblotting. MSCs were isolated, genetically labeled, expanded in vitro, seeded onto small intestinal submucosa (SIS) and used for autologous bladder augmentation.

RESULTS

Porcine MSCs are morphologically and immunophenotypically similar to human MSCs. Culturing MSCs at low density enhances proliferation rates. MSCs consistently differentiate into mature SMCs in vitro when maintained at confluence. Labeled MSCs grew on SIS over one week in vitro and survived a 2-week implantation as an autologous bladder augment in vivo. Some label-positive cells with SMC morphology were detected, but most SMCs were negative. Notably, many cells with a urothelial morphology stained positively.

CONCLUSIONS

Porcine MSCs have similar properties to MSCs from other species and consistently undergo differentiation into mature SMC in vitro under specific culture conditions. Labeled MSCs within SIS may assist tissue regeneration in augmentation cystoplasty but may not significantly incorporate into smooth muscle bundles.

Rapid communication: effects of Steris 1 sterilization and Cidex ortho-phthalaldehyde high-level disinfection on durability of new-generation flexible ureteroscopes

BACKGROUND AND PURPOSE

The effects of commonly used reprocessing methods on flexible ureteroscope longevity have never been examined. We prospectively studied the effects of Steris 1 sterilization and Cidex ortho-phthalaldehyde (OPA) high-level disinfection (HLD) on the image quality, physical structure, and deflective properties of two new flexible ureteroscopes.

MATERIALS AND METHODS

Two identical "out-of-the-box" Storz 11278AU1 flexible ureteroscopes (Karl Storz Endoscopy, Tuttlingen, Germany) were sterilized individually using the Steris 1 system (Steris Mentor, Ohio) or disinfected with Cidex OPA (Advanced Sterilization Products, J&J, Irvine, CA) for 100 trials followed by a crossover to the other method for another 100 trials over a period of 1 year. After every five trials, optical quality, angle of deflection, and fiber damage were analyzed in the laboratory. Throughout the study, neither of these ureteroscopes was used clinically.

RESULTS

After 100 trials, ureteroscope 1, which was sterilized initially in the Steris system, had a 12-mm tear on its shaft (noted after the 17th trial), 297 damaged fibers, and a 37% drop in resolution (loss of 3.75 lines/mm). There was no change in deflection from baseline. In contrast, after 100 cycles, ureteroscope 2, which was subjected to HLD with Cidex OPA, had no visible external damage, a 0% change in resolution, 10 damaged fibers, and no change in deflection. After the crossover, ureteroscope 2 developed a semilunar defect that obscured the endoscopic view, whereas there was no further significant damage to ureteroscope 1.

CONCLUSION

After 100 cycles, the Steris 1 system rendered the flexible ureteroscope unusable, whereas HLD with Cidex OPA had minimal adverse impact.

Rapid Communication: Transvaginal Single-Port NOTES Nephrectomy: Initial Laboratory Experience

BACKGROUND AND PURPOSE

Natural orifice translumenal endoscopic surgery (NOTES) using purpose-built equipment has never been applied to urologic surgery. Herein, we present our initial experience with a trans-vaginal single-port NOTES nephrectomy.

METHODS AND RESULTS

An acute experiment was performed in a female farm pig. A single 12-mm trocar was placed in the midline and the TransPort Multi-Lumen Operating Platform (USGI Medical, San Clemente, CA) was passed transvaginally. This flexible device has four working channels and can be locked into position, thereby creating a rigid multitasking platform that allows two-handed tissue manipulation. Dissection was performed using an endoscopic needle knife and a tissue grasper for retraction. Via the 12-mm port, the renal artery and vein were taken separately with a vascular EndoGIA and standard laparoscopic titanium clips, respectively. The kidney was placed in a 10-mm EndoPouch retriever and removed intact via the vagina. The total operative time was 300 minutes.

CONCLUSION

Transvaginal NOTES nephrectomy can be accomplished in a porcine model. Additional testing on survival animals is necessary to validate this approach.