Biomedical subjects

Takeshi Inagaki

Publications and source records attributed to Takeshi Inagaki.

At least 19 recordsLinked to original sources

PubMed2006

Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor.

Obstruction of bile flow results in bacterial proliferation and mucosal injury in the small intestine that can lead to the translocation of bacteria across the epithelial barrier and systemic infection. These adverse effects of biliary obstruction can be inhibited by administration of bile acids. Here we show that the farnesoid X receptor (FXR), a nuclear receptor for bile acids, induces genes involved in enteroprotection and inhibits bacterial overgrowth and mucosal injury in ileum caused by bile duct ligation. Mice lacking FXR have increased ileal levels of bacteria and a compromised epithelial barrier. These findings reveal a central role for FXR in protecting the distal small intestine from bacterial invasion and suggest that FXR agonists may prevent epithelial deterioration and bacterial translocation in patients with impaired bile flow.

Animals↗

PubMed2006

[The recurrence of urothelial carcinoma in situ at the fossa navicularis of the urethra and the glans penis arising eight years after transurethral resection of a bladder tumor to treat superficial bladder cancer].

A 63-year-old man underwent transurethral resection of a bladder tumor to treat superficial bladder cancer in 1995. Histological examination showed urothelial carcinoma, G2>G3 with carcinoma in situ (CIS) at the bladder neck. He underwent postoperative intravesical bacillus Calmette-Guerin (BCG) therapy. In June, 2003, he complained of rubor of his external urethral meatus and visited our clinic. Biopsies at the external urethral meatus and the fossa navicularis of the urethra showed CIS. Radiological examinations, cystourethroscopy and multiple biopsies from other sites of urothelium, including bladder and urethral mucosa, did not reveal any other malignancies. Thereafter, partial penectomy and bilateral inguinal lymphadenectomy were performed. Histological examinations showed CIS at the urethral mucosa of the fossa navicularis and the skin of the glans penis. Postoperative urine cytologies were negative.

BCG Vaccine↗

PubMed2005

Pain control requirements for percutaneous ablation of renal tumors: cryoablation versus radiofrequency ablation--initial observations.

PURPOSE: To retrospectively compare the pain control requirements of patients undergoing computed tomography (CT)-guided percutaneous radiofrequency (RF) ablation with those of patients undergoing CT-guided percutaneous cryoablation of small (< or = 4-cm) renal tumors. MATERIALS AND METHODS: The study was HIPAA compliant and received institutional review board exemption; informed consent was not required. Medical and procedure records of patients who underwent RF ablation and cryoablation of renal tumors from June 19, 2003, to February 28, 2004, were retrospectively reviewed for clinical data, tumor characteristics, and anesthesia information. During the study period, 10 men (mean age, 66.5 years) underwent cryoablation of 11 renal lesions, and 14 patients (11 men, four women; mean age, 68.1 years) underwent RF ablation of 15 renal tumors. Analgesic and sedative requirements during the procedure were compared. Standard anesthesia consisted of 5 mL of 1% lidocaine injected locally, and conscious sedation consisted of 50 microg of fentanyl and 1 mg of midazolam administered intravenously. The Fisher exact test and Student t test were used to compare clinical factors and drug requirements between the two groups. RESULTS: There was no difference in terms of patient demographics, tumor diameter, or distribution of central versus noncentral lesions between the two groups. Cryoablation was associated with a significantly lower dose of fentanyl (165.0 microg [RF group] vs 75.0 microg [cryoablation group]; P < .001) and midazolam (2.9 mg [RF group] vs 1.6 mg [cryoablation group]; P = .026). In the RF group, one patient required general anesthesia, one patient required supplemental narcotics (5 mg of oxycodone) and sedatives (1 mg lorezapam), and one patient became apneic for a brief interval after receiving additional narcotics for pain during the procedure. An additional RF session was terminated early in one patient because of pain, and further medication could not be administered owing to bradycardia. No patients in the cryoablation group required any additional or alternate anesthetics. CONCLUSION: Image-guided percutaneous cryoablation of small (< or = 4-cm) renal lesions appears to require less analgesia than RF ablation. Prospective trials with validated pain scales are needed to examine this further.

Aged↗

PubMed2005

Fibroblast growth factor 15 functions as an enterohepatic signal to regulate bile acid homeostasis.

The liver and intestine play crucial roles in maintaining bile acid homeostasis. Here, we demonstrate that fibroblast growth factor 15 (FGF15) signals from intestine to liver to repress the gene encoding cholesterol 7alpha-hydroxylase (CYP7A1), which catalyzes the first and rate-limiting step in the classical bile acid synthetic pathway. FGF15 expression is stimulated in the small intestine by the nuclear bile acid receptor FXR and represses Cyp7a1 in liver through a mechanism that involves FGF receptor 4 (FGFR4) and the orphan nuclear receptor SHP. Mice lacking FGF15 have increased hepatic CYP7A1 mRNA and protein levels and corresponding increases in CYP7A1 enzyme activity and fecal bile acid excretion. These studies define FGF15 and FGFR4 as components of a gut-liver signaling pathway that synergizes with SHP to regulate bile acid synthesis.

Animals↗

PubMed2005

Comparison of erbium:yttrium-aluminum-garnet and holmium:yttrium-aluminum-garnet lasers for incision of urethra and bladder neck in an in vivo porcine model.

OBJECTIVES: To evaluate, in an animal model, differences in wound healing and scar formation in healthy urethra and bladder neck incised with the erbium (Er):yttrium-aluminum-garnet (YAG) and holmium (Ho):YAG lasers. METHODS: In each of 18 domestic pigs, three 1-cm-long incisions were made, two at the bladder neck and one in the mid-urethra, using either the Er:YAG laser (9 pigs) or the Ho:YAG laser (9 pigs). In each laser group, 3 animals were killed on postoperative days 0, 6, and 14. The width of collateral damage, as evidenced by coagulation necrosis and granulation tissue at the wound base, and the incision depth were evaluated during tissue analysis. RESULTS: The collateral damage with the Er:YAG laser at postoperative day 0, 6, and 14 was 20 +/- 5, 900 +/- 100, and 430 +/- 100 microm, respectively. The collateral damage with the Ho:YAG laser was 660 +/- 110, 2280 +/- 700, and 1580 +/- 250 microm, respectively. The amount of granulation tissue was significantly less (P <0.05) at all time points with the Er:YAG laser. Similarly, the incision depths for the Er:YAG and Ho:YAG laser at postoperative day 6 (1100 +/- 200 microm versus 1500 +/- 300 microm, respectively) and 14 (670 +/- 140 microm versus 1240 +/- 140 microm, respectively) were also significantly less (P <0.05) for the Er:YAG laser group, indicating faster healing of the wound created. CONCLUSIONS: In this in vivo animal study, incisions in the urethra and bladder neck made with the Er:YAG laser healed faster and with less scar formation than incisions made with the Ho:YAG laser.

Aluminum↗

PubMed2005

Exploring the learning curve, pathological outcomes and perioperative morbidity of laparoscopic partial nephrectomy performed for renal mass.

PURPOSE: We investigated the learning curve, pathological results and perioperative morbidity of laparoscopic partial nephrectomy (LPN). MATERIALS AND METHODS: The records of all LPN cases at our institution between January 1999 and March 2004 were reviewed. Of 223 cases 217 (97.3%) were performed for an enhancing renal mass. RESULTS: Mean tumor size was 2.6 cm (range 1 to 10) and 95.4% of patients had a normal contralateral kidney. Transient vascular control was performed in 75.1% of cases. Mean operative time (186 minutes) decreased with surgeon experience (p = 0.003) but was independent of tumor size (p = 0.964). Mean warm ischemia time (27.6 minutes) depended on tumor size (p = 0.005) but not on experience (0.964). Mean blood loss was 385 cc and the perioperative transfusion rate was 6.9%. Postoperative complications occurred in 23 cases (10.6%) with the most common being ileus (1.8%), bleeding (1.8%) and urinary leakage (1.4%). Although the mean serum creatinine change after LPN was a function of tumor size (p <0.001), it was clinically insignificant (0.13 mg/dl). No significant relationship was observed between warm ischemia time and creatinine change (p = 0.262). The final pathological evaluation revealed renal cell carcinoma in 144 patients (66.4%) and the overall positive margin rate was 3.5%. Only 2 renal cell carcinoma recurrences in the operated kidney (1.4%) were identified (mean followup +/- SD 24 +/- 12 months). CONCLUSIONS: LPN is an effective approach for treating small renal masses with low perioperative morbidity. Contrary to previous reports, more than 30% of the enhancing renal lesions excised in this series were found to be benign on final pathological evaluation.

Adult↗

PubMed2005

Percutaneous radio frequency ablation of renal masses: results at a 2-year mean followup.

PURPOSE: We describe our experience with and results of percutaneous computerized tomography guided radio frequency ablation (RFA) for small (less than 4 cm) renal tumors at a 2-year mean followup. MATERIALS AND METHODS: A total of 49 patients (60 renal tumors) with a mean age of 63.9 years underwent percutaneous RFA. Indications for RFA were severe comorbidities or previous abdominal surgery precluding operative management, or hereditary conditions predisposing to multiple tumor recurrence. Persistent enhancement on initial followup imaging was considered incomplete treatment and all such patients underwent biopsy and were offered repeat RFA. Enhancement or enlargement on subsequent imaging was considered tumor recurrence and these patients were counseled regarding further therapy. RESULTS: Three patients (4 tumors) were excluded from evaluation due to death from unrelated causes or loss to followup. A total of 46 patients (56 tumors) were available for evaluation at a mean followup of 27.5 months (range 12 to 48). Six tumors were incompletely treated with the first RFA and successfully treated with a second session. Recurrences after successful initial treatment were seen in 3 of 46 patients. These recurrences developed 24, 25 and 31 months following RFA, respectively, and all occurred in patients with a central tumor of 3.0 cm or greater. Overall local control was achieved in 94.6% of tumors (53 of 56). CONCLUSIONS: RFA is an emerging alternative treatment modality for small renal tumors. Larger (greater than 3.0 cm) central tumors represent unique technical challenges, making these tumors more prone to recurrence. Long-term followup is needed to establish the oncological durability of this technique.

Adult↗

PubMed2005

Laparoscopic pyeloplasty: current status.

OBJECTIVE: To review current publications and report our results and long-term follow-up of laparoscopic transperitoneal pyeloplasty for pelvi-ureteric junction (PUJ) obstruction. PATIENTS AND METHODS: In all, 147 laparoscopic transperitoneal pyeloplasties were performed between August 1993 and November 2000 (mean patient age 35.7 years, range 10-85). All patients were diagnosed with PUJ obstruction by symptoms and intravenous urography, radionuclide diuretic renography or ultrasonography. An Anderson-Hynes dismembered pyeloplasty (106), Y-V plasty (28), Fenger plasty (11) and others (two) were used, according to the intraoperative findings. Twenty-five patients had secondary obstruction, having had previous surgery to the PUJ. The mean (range) follow-up was 24 (3-84) months; all patients were followed clinically and radiologically. RESULTS: The mean operative duration time was 246 (100-480) min and estimated blood loss was 158 mL. Crossing vessels were identified in 80 cases. The success rate for all, primary and secondary patients was 95%, 98% and 84%, respectively. With one exception, all failures occurred within 6 months. Twenty-one patients (22 renal units) had simultaneous laparoscopic pyeloplasty and lithotomy; they were treated successfully and all have an intact PUJ, and 20 renal units (90%) were stone-free. The overall complication rate was 8.8%. CONCLUSIONS: This series has comparable success rates to those of open pyeloplasty and the morbidity was minimal. Laparoscopic pyeloplasty may soon become the standard operation for PUJ obstruction, especially with crossing vessels.

Adolescent↗

PubMed2005

[Pyoderma gangrenosum of the penis presenting as Fournier's gangrene: a case report].

We report a case of pyoderma gangrenosum of the penis presenting as Fournier's gangrene. A 77-year-old man who had undergone radiotherapy for localized prostate cancer 16 month earlier, presented with penile pain and fever. Symptoms began with erythema and induration on the dorsal surface of the penile shaft followed by spontaneous purulent drainage with severe pain. Magnetic resonance imaging was unremarkable except for swelling of the penile skin. Biopsy of the ulcerative penile lesion demonstrated a nonspecific inflammation without vasculitis or malignancy. Despite broad-spectrum antibiotics and debridement, the penile lesion extended and new satellite lesions developed as pustules on the glans. Since cultures were negative for aerobic and anaerobic bacteria, a course of intravenous prednisolone was then initiated at 100 mg/day. Within 24 hours the temperature normalized, progression of the penile lesions stopped and became convalescent. The steroid was then tapered and discontinued. The penile lesions healed slowly during the subsequent 1-month period. Based on the clinical course and histopathological findings as well as exclusion of other ulcerative conditions, a diagnosis of pyoderma gangrenosum was made. Penile involvement of this non-infectious ulcerating skin disease has rarely been reported. Pyoderma gangrenosum affecting the penile skin, such as that in present case, may show a similar presentation as Fournier's gangrene. Prompt differential diagnosis is mandatory since effective management for each processes is markedly different.

Aged↗

PubMed2005

[Radical cystectomy for invasive bladder carcinoma in patients 75 years old or older].

Between 1995 and 2004, 43 patients underwent radical cystectomy and urinary diversion for the treatment of invasive bladder cancer at our institution. Of these patients, seven who were 75 years old or older, were considered elderly. Survival and treatment outcome of these patients were compared to younger counterparts stratified into three groups by age at diagnosis (12 patients younger than 64, 12 patients 65 to 69 years, and 12 patients 70 to 74 years). Preoperative morbidity was encountered in 57% of the elderly patients, and 42% of the elderly patients had two or more complications. There was one operative death (14%) among the elderly patients but no such deaths in the 3 younger groups. The postoperative complication rate for patients age 75 years or older was 86%, compared to 75% for patients younger than 64, 75% for those age 65 to 69 and 83% for those age 70-74. The prevalence did not differ significantly between the older and youger patients. There were no cancer deaths among the elderly patients, but 8 of the 36 younger patients died of cancer. The cancer-specific 5-year survival rate was 100% at 34 months in the elderly population. These findings suggest that radical cystectomy and urinary diversion is a relatively safe procedure and a curative operation is worth attempting in elderly patients with invasive bladder cancer, if they are in generally good health.

Age Factors↗

PubMed2005

[Carcinoma in situ of the bladder involving the prostate with an unusual invasive pattern following BCG therapy: a case report].

We report a case of carcinoma in situ (CIS) of the bladder involving the prostate with an unusual invasive pattern following Bacillus Calmette Guerin (BCG) therapy. A 41-year-old man achieved complete response after a course of intravesical instillation of BCG for diffuse CIS of the bladder. Two years later, urine cytology became positive. We performed random biopsy of the bladder and urethra three times and examined the bilateral upper urinary tract with retrograde pyelography and split urine cytology. However, none of these examinations revealed any malignant features, leading to a suspicion that the prostate was the recurrent site. Transrectal needle biopsy of the prostate revealed urothelial carcinoma (UC) at the transition between bladder and prostate. Transurethral biopsy of the prostatic urethra also detected UC in a core of the bladder neck only. Under a diagnosis of UC involving the prostate, we performed total cystectomy with ileal conduit diversion. Histopathological findings of the surgical specimen showed prostatic stromal invasion of the tumor. In this case, CIS at the bladder neck might directly and silently invade the prostatic stroma, thus transurethral biopsy contributed little to the diganosis. We recommend transrectal needle biopsy of the prostate as well as TUR biopsy in such rare cases.

Administration, Intravesical↗

PubMed2004

A kindred with Cockayne syndrome caused by multiple splicing variants of the CSA gene.

Cockayne syndrome (CS) is an autosomal recessive disorder, which is associated with abnormal UV hypersensitivity, growth retardation, and psycho-neural abnormalities. Recently, CSA protein was found to be associated with CS. We obtained mRNAs from immortal lymphoblasts derived from members of the kindred, and sequenced the CSA gene of all family members after reverse transcription (RT) of the coding region. The intact length of the CSA transcript was found in all family members except the proband with CS. Multiple abnormal splicing variant forms were revealed in all cases. No mutation was found in the sequences of the splice donor and acceptor sites of each exon in the CSA gene. UVA irradiation suppressed cell growth in the proband. There was no significant alteration of UVA sensitivity among the normal control and the family members except for the proband. These data suggest that multiple splicing variant forms of CSA mRNA, in the absence of the full-length form of the mRNA, are associated with CS.

Adult↗

PubMed2004

Evaluation of water jet morcellation as an alternative to hand morcellation of renal tissue ablation during laparoscopic nephrectomy: an in vitro study.

OBJECTIVES: To evaluate the feasibility and safety of morcellation with a new prototype device that uses high-pressure water flow as a cutting/ablating tool and compare it with standard manual morcellation. METHODS: Ten porcine kidneys were morcellated with the new water jet device and ten with conventional manual morcellation. Morcellation in all cases was performed in commercially available entrapment bags. The two groups were evaluated for morcellation time, fragment size, and perforation rates (macroscopic and microscopic). RESULTS: The kidney size in both groups was similar. Morcellation was significantly (P <0.0001) faster in the water jet morcellator group than in the hand morcellation group (5.6 versus 11.9 minutes). The macroscopic evaluation after filling the entrapment bags with normal saline revealed 4 (40%) and 2 (20%) pinhole perforations in the water jet and hand morcellation groups, respectively. The microscopic evaluation revealed an 80% perforation rate in the water jet group and a 20% rate in the hand morcellator group. The size of the resulting fragments in the water jet group was not available, because the morcellated kidney was transformed in a semiliquid form. Therefore, cytology evaluation of the tissue was not possible. CONCLUSIONS: Water jet technology can be used to morcellate renal porcine tissue effectively. It is faster, but the problems of safety and histologic evaluation must be solved before this promising technology can be used in a clinical setting.

Animals↗

PubMed2004

Laparoscopic-assisted nephrectomy with inferior vena cava tumor thrombectomy: preliminary results.

OBJECTIVES: To evaluate the feasibility and outcome of laparoscopic-assisted radical nephrectomy and inferior vena cava (IVC) tumor thrombectomy in patients with renal cell carcinoma and level I IVC tumor thrombus. METHODS: The clinical, operative, and pathologic data were retrospectively obtained from patients undergoing the above-mentioned procedure for renal tumors involving the IVC. This approach involved laparoscopic dissection of the kidney and renal vasculature/IVC. After renal artery ligation, an 8 to 12-cm incision was made from the tip of the 11th rib extending anteriorly toward the midline. Through this incision, a Satinsky vascular clamp was placed on the IVC in such a way as to include all the caval thrombus. The tumor thrombus was removed en bloc with the kidney and the cavotomy repaired with a running suture. RESULTS: Four obese patients underwent transperitoneal laparoscopic-assisted right nephrectomy with inferior vena cava (IVC) thrombectomy. The mean tumor size was 9 cm (range 6 to 13), with the thrombus extending 2 cm into the IVC in all cases. Patients had a mean body mass index of 32.8 (range 30.5 to 37.2) and a mean American Society of Anesthesiologists score of 2.8 (range 2 to 3). The mean operative time was 248 minutes (range 225 to 274). The mean estimated blood loss was 517 mL (range 250 to 900). No intraoperative or postoperative complications occurred. The mean hospital stay was 6.2 days (range 4 to 11, median 5). CONCLUSIONS: Laparoscopic-assisted nephrectomy and IVC thrombectomy is a difficult but feasible procedure. This approach allows a smaller incision than a typical open approach. Additional studies are needed to examine the advantages of this approach over a pure open approach.

Aged↗

PubMed2004

Pancreatic injuries during laparoscopic urologic surgery.

OBJECTIVES: To review our experience with pancreatic injury (PI) associated with urologic laparoscopy. PI associated with urologic laparoscopy is uncommon. METHODS: From January 1999 to April 2004, 890 laparoscopic operations for upper urinary tract pathologic findings were performed, of which 574 were left-sided procedures. We reviewed the medical records for recognized intraoperative or postoperatively documented PI and recorded the patient demographic data and intraoperative and postoperative management. RESULTS: Four PIs were identified, all associated with left-sided procedures. The overall rate of PI was 0.44%. Two injuries occurred during left radical nephrectomy (2.1%) and two during left adrenalectomy (8.6%). The mean tumor size was 6 +/- 3.4 cm. The diagnosis was made intraoperatively in 1 patient, postoperative midepigastric pain with elevated serum amylase levels was the clinical presentation in 2 patients, and the incidental finding of pancreatic tissue in the final pathologic specimen confirmed the injury in the fourth patient. A prolonged pancreatic fistula developed only in 1 case. Three patients were treated conservatively and computed tomography-guided drainage of a pancreatic collection was required in one. The mean hospital stay was 18 days (range 4 to 57). CONCLUSIONS: PI is uncommon but can result in significant morbidity. Intraoperative detection and repair can minimize sequelae. Management with conservative measures and percutaneous drainage is usually successful, although a prolonged postoperative course can be expected.

Humans↗

PubMed2004

Tumor capacitance: electrical measurements of renal neoplasia.

PURPOSE: Studies have demonstrated that biological tissues possess unique electrical properties. We evaluate the electrical properties of renal tumors using a specialized probe with the capability of measuring intra-tissue capacitance in an ex vivo model of fresh surgically excised tissue. MATERIALS AND METHODS: An electrical monitoring device was used to measure tissue capacitance at a frequency of 1 MHz on 34 ex vivo kidney specimens freshly obtained after surgical excision. Tissue capacitance was promptly measured in the excised tumor as well as surrounding normal parenchyma and fat. Dielectric permittivity in each tissue was calculated using the measured capacitance data. These data were compared and correlated to pathological findings. RESULTS: The final pathology on the 34 specimens revealed 28 renal cell carcinomas (RCC), 3 oncocytomas and 3 angiomyolipomas. In patients with RCC dielectric permittivity of tumor tissue was 1.43 +/- 0.39 times greater than that of surrounding normal parenchyma (p < 0.001). The average tumor-to-normal tissue dielectric permittivity ratio for RCC was significantly greater than that for angiomyolipoma (1.43 +/- 0.39 vs 0.73 +/- 0.77, p < 0.05) but similar to that for oncocytoma (1.43 +/- 0.39 vs 1.63 +/- 0.77, p = 0.39). CONCLUSIONS: Tissue capacitance measurements may be used to differentiate renal tumor from surrounding normal tissue. In vivo studies will ultimately determine the clinical use of this technology in localizing renal neoplasms and differentiating between malignant and benign tissues.

Adenoma, Oxyphilic↗

PubMed2004

Management of secondary ureteropelvic junction obstruction after failed primary laparoscopic pyeloplasty.

PURPOSE: Laparoscopic pyeloplasty has been established as a minimally invasive alternative to open pyeloplasty. However, little is known about the treatment of patients in whom this technique fails. We present our experience with treating ureteropelvic junction obstruction after failed primary laparoscopic pyeloplasty. MATERIALS AND METHODS: From August 1993 to September of 2003, 227 patients underwent laparoscopic pyeloplasty for primary ureteropelvic junction obstruction. Of these patients 10 (4.4%), including 6 females and 4 males 24 to 62 years old (mean age 42.1), underwent secondary treatment after laparoscopic pyeloplasty failed. The type of secondary intervention varied by anatomical factors, and patient and surgeon preference. Success was defined as symptomatic relief and improved radiographic imaging at latest followup. RESULTS: Secondary interventions were repeat laparoscopic pyeloplasty in 1 patient, retrograde endoscopic balloon dilation in 2 and endopyelotomy in 7 (laser, cold knife and cutting balloon endopyelotomy in 3, 2, and 2, respectively). No postoperative complications were seen. Patients were followed for a mean of 25.5 months (range 3 to 96) after the second procedure. Seven of 10 secondary interventions (70%) were successful with no obstruction on followup imaging. Three of 10 interventions (30%) failed, namely 1 laparoscopic pyeloplasty, 1 endoscopic balloon dilation and 1 laser endopyelotomy. Failure of the second procedure occurred at a mean of 9.3 months. CONCLUSIONS: When given the choice, most patients select endoscopic management after failed primary laparoscopic pyeloplasty due to its minimally invasive nature and low complication rate. Success rates are 70% with repeat intervention. Some patients require a third intervention.

Adult↗

PubMed2004

Laparoscopic partial nephrectomy: evaluation of long-term oncological outcome.

PURPOSE: Laparoscopic partial nephrectomy (LPN) has emerged as a viable alternative to open surgery for renal tumors less than 4 cm. We present oncological followup of patients treated with laparoscopic nephron sparing surgery at our institution. MATERIALS AND METHODS: Between September 1996 and December 2001, 48 patients who underwent LPN for clinically localized tumors were found to have pathologically proven renal cell carcinoma. Medical and operative records were reviewed for clinical characteristics, pathological findings and followup information. RESULTS: Mean patient age was 59.7 years (range 32 to 81) and mean followup was 37.7 months (range 22 to 84). Mean tumor size was 2.4 cm (range 1.0 to 4.0). Final pathological stage was pT1 in 42 patients (87.5%) and pT3a in 6 (12.5%). Histology revealed clear cell in 32 patients (66.7%), papillary in 10 (20.8%), chromophobe in 3 (6.3%), collecting duct in 1 (2.1%) and unclassified in 2 (4.2%). Intraoperative frozen section biopsies revealed negative margins in all cases. Final surgical margins were positive in 1 patient (2.1%). Followup evaluation consisting of physical examination and yearly cross-sectional imaging, which revealed no recurrences in 46 of 48 patients (95.8%). One patient with von Hippel-Lindau disease was found to have local recurrence 18 months after LPN and observation was elected. The second patient had recurrence in the same kidney away from the original tumor site approximately 4 years later. CONCLUSIONS: LPN is an effective treatment modality for clinically localized renal cell carcinoma. Oncological outcomes at a mean followup of 3 years are promising, although the durability of oncological outcomes must be determined.

Adult↗