Meraney A

da Vinci Skills Simulator Construct Validation Study: Correlation of Prior Robotic Experience With Overall Score and Time Score Simulator Performance

OBJECTIVE To assess the construct validity of the da Vinci Skills Simulator (Intuitive Surgical, Sunnyvale, CA). Ideally, a well-designed simulator should demonstrate construct validity, which is defined in this study as the correlation between robotic surgical experience and performance on the simulator. PATIENTS AND METHODS Thirty-nine surgeons (18 [46%] group I [0-20 robotic cases]; 8 [21%] group II [21-150 robotic cases]; and 13 [33%] group III [>150 robotic cases]) were enrolled from September 2010 to December 2010. Participants completed 24 virtual-reality exercises on the da Vinci Skills Simulator. Data on 12 performance metrics were collected by the software. Overall means for score and time across exercises were analyzed. RESULTS Overall scores (64.7%/79.1%/87.4%) and time scores (39.1%/58.6%/87.3%) were significantly different among surgeons in groups I-III (P <.001) and demonstrated significant linear relationships (P <.001) for all 24 exercises. Comparisons between the 3 groups using a univariate general linear model (GLM) was used to compare groups I and II and II and III. Groups I and II differed using overall score for 15 exercises and time score for 11 exercises. Groups II and III differed using overall score for 6 exercises and time score for 15 exercises. Mean overall score for 1 exercise displayed significance between both groups I and II and II and III; while using time score, 5 exercises displayed significance between surgeons in groups I and II and II and III. CONCLUSION Initial construct validity analysis revealed that both overall scores and time scores showed a significant linear relationship when comparing the surgeons in groups I, II, and III. Overall score seems to be a stronger indicator for differences between surgeons in groups I and II. Time score seems to be a stronger indicator for differences between surgeons in groups II and III.

Active surveillance of renal masses: an analysis of growth kinetics and clinical outcomes stratified by radiological characteristics at diagnosis

AIMS To determine the growth rate of renal masses (RMs) under active surveillance (AS), and to describe the clinical outcome of AS patients. MATERIALS AND METHODS We conducted a retrospective review of an AS database to obtain demographics, radiological and pathologic characteristics and RM size of patients. RMs were followed at 6-12 month intervals for ≥1 year with computed tomography (CT), magnetic resonance imaging (MRI), or renal ultrasound. Kaplan-Meier analysis determined the annual likelihood of intervention. RMs were divided into 3 radiographic subcategories (solid, cystic, and angiomyolipoma). A linear regression model determined RM growth rates. RESULTS 131 RMs in 114 patients were included. Median age, Charlson Comorbidity Index score and mean follow-up were 69.1 years, 4.0 and 4.2±2.6 years, respectively. Maximal tumor diameter (MTD) at diagnosis was 2.1 ± 1.3 cm. 49 RMs exhibited negative or zero net growth. Mean MTD growth rate for all RMs was 0.72±3.2 (95% CI: 0.16-1.28) mm/year. When stratified by MTD at diagnosis, mean RM growth rates were 0.84, 0.84, 0.44, 0.74 and 0.71 mm/year for RMs ≤1 cm, 1-≤2cm, 2-≤ 3cm, 3-≤ 4cm and ≥4cm, respectively (p≤0.01). The 5 and 10-year freedom from intervention rates were 93.1% and 88.5%, respectively. There was a single case of suspected metastases, but no deaths related to kidney cancer. CONCLUSIONS RMs under AS grew slowly, and had a low incidence of requiring surgical intervention and progression. Solid enhancing masses grew slowly, and were more likely to trigger intervention. AS should be considered for selected patients with small RMs.

Spontaneous bladder perforation unrelated to trauma or surgery.

Urinary bladder ruptures (UBR) typically result from either blunt or penetrating trauma, or from iatrogenic surgical injuries. Patients typically present with symptoms including lower abdominal pain, haematuria, dysuria and anuria. Here, we report on a rare case of spontaneous bladder perforation. A 60-year-old, Caucasian woman initially presented with lower abdominal pain and diarrhoea, and was subsequently found to have an elevated serum creatinine level. A CT cystogram revealed a leak from the bladder. The patient consented to exploratory laparotomy and repair of the non-traumatic bladder perforation. At the time of the last follow-up, given the fact that the patient’s urodynamics were unremarkable and that she was emptying her bladder well (repeat postvoid residual was zero), the patient was informed that she did not require future urological follow-up unless difficulties arise.

Gross haematuria associated with penetration of an inferior vena cava filter into the right renal collecting system

Inferior vena cava (IVC) filters are a viable alternative for patients with venous thromboembolic disease for whom standard anticoagulation therapy is contraindicated. Rare complications associated with their use, however, include misplacement and IVC penetration. We report a case of a 63-year-old woman who developed gross haematuria following IVC filter penetration into both the right renal collecting system and renal pelvis, for which open caval removal and reconstruction was required. This is an unusual case of IVC filter penetration causing symptomatic haematuria and requiring surgical intervention.

Malignant renal angiomyolipoma without tuberous sclerosis

A 68-year-old woman presented with abdominal pain, fatigue, anorexia and night sweats. Imaging studies identified a vascular mass extending from the upper pole of the right kidney with anterior displacement to the abdominal midline, consistent with renal cell carcinoma. A radical nephrectomy and right pelvic lymph node dissection was performed. Pathology determined a grade 4 malignant epithelioid angiomyolipoma that invaded hilar and perinephric adipose tissue. Gross tumour was also present within the renal vein, sinus, pelvis, capsule and perinephric fat. The tumour was HMB-45 positive, supporting the diagnosis of a typical angiomyolipoma in association with the high-grade epithelioid tumour.