Retrospective Analysis of Laparoscopic Partial Nephrectomies Using the Zero Ischemia Technique.

PURPOSE: To report a series of 89 off-clamp laparoscopic partial nephrectomies (LPN) performed without using any additional "nephron sparing" manipulations. METHODS: Retrospective analysis of surgical characteristics, complications, postoperative results, and renal function changes. RESULTS: Between March 2008 and May 2014, 89 LPN using zero ischemia technique were performed. Most of the patients (61.8%) were male. The median age was 62 years (23-88). The mean BMI was 27.5 kg/m2 (20.8-54.2). The median tumor size was 3.0 cm (1.0-8.0). Tumor location was upper, middle, and lower part of the kidney in 33 (37.0%), 42 (47.2%), and 14 (15.7%) of patients, respectively. The median operative time was 154 min (58-289). The median hemoglobin change was -1.6 g/dL (0.5-5.5). The transfusion rate was 7.9%. The mean preoperative glomerular filtration rate was 96.6 mL/min (21.5-180.0) with a mean postoperative decline of 6.52 mL/min. The mean creatinine elevation after LPN was 0.09 mg/dL. The median hospital stay was 6 days (2-24). The intraoperative complications rate was 2.3%. Early postoperative complication rate was 33.7%. Late complications occurred in 6.7%. In 7 cases (7.9%), the surgical margins were microscopically involved by tumor cells. Conversion rate was 3.4%. CONCLUSION: Data obtained in the current series show that laparoscopic partial nephrectomy can be successfully performed without hilar clamping. Our results are comparable with contemporary data. Larger prospective studies would be helpful in assessing the evidence-based advantages of the "zero ischemia" technique.

Limited field noncontrast computerized tomography for followup of ureteral stones: initial results.

PURPOSE: Due to high specificity and sensitivity noncontrast computerized tomography is increasingly used to diagnose and follow patients with ureteral stones. We evaluated the feasibility of limited field noncontrast computerized tomography to follow patients with ureteral stones. MATERIALS AND METHODS: Included in the study were 71 patients who underwent diagnostic and followup noncontrast computerized tomography due to ureteral stones. According to stone position on the first diagnostic scan a limited field batch from the followup scan was formed and examined by an independent radiologist. Radiation doses and rates of potentially missed findings in the batch were compared to those of the full followup noncontrast scan. RESULTS: Average full followup noncontrast computerized tomography length was 46.5 cm and average batch length was 20.7 and 13.8 cm for proximal and distal stones, respectively. The average full followup noncontrast scan radiation dose was 12.2 mSv. Average batch doses were 6.1 and 4.1 mSv for proximal and distal stones, respectively (p = 0.002), resulting in a radiation exposure reduction of 48.8% for proximal stones and 66% for distal stones. In 3 cases additional clinical information (not including hydronephrosis) was missed when relying only on batch images. This additional information did not impact further urological treatment. CONCLUSIONS: Limited field noncontrast computerized tomography is a feasible option for following patients diagnosed with ureteral stones. It may lead to significantly lower radiation exposure.

Shielding artificially increases the attenuation of water: study of CT gradient attenuation induced by shielding (CT GAINS).

RATIONALE AND OBJECTIVES: Quantitatively analyze the computed tomography (CT) attenuation effects caused by bismuth shields, which are used to reduce superficial organ dose. MATERIALS AND METHODS: The solid water uniformity section of the American College of Radiology CT phantom was scanned with a modified chest CT protocol. Scans were performed with a bismuth breast shield in multiple configurations, emphasizing three clinically relevant orientations. Attenuation effects were measured as changes in mean Hounsfield unit (HU) values of equal midsagittal regions of interest (ROI). Multiple statistical techniques were used in regression analysis. RESULTS: Bismuth shielding resulted in significant positive shifts of the expected Hounsfield unit values. The mean nonshielded CT attenuation was -0.16 ± 0.75 HU. Based on the clinically relevant ROI distance from the shield (~3-16 cm), the shielded values ranged from 43.8-4 HU, 45.8-10.1 HU, and 50.6-4.5 HU for shields 1, 2, and 3, respectively. All shield configurations displayed a statistically significant shift (P < .0001) at all distance ranges. The best fitting regression model was a quadratic function of distance versus logarithmic function of HU. A prediction table of the approximate shift in water HU values as a function of ROI distance from the shield was generated per shield type from their respective close-fitting regressions. CONCLUSIONS: The data support the claim that bismuth shields increase the attenuation of water, which can cause inaccurate characterization of simple fluid, giving the appearance of complex fluid or even solid density. However, there is potential for anticipation of the attenuation effects to validate continued use of these shields for dose reduction.

Collecting system involvement by renal tumor: are CT measurements reliable enough?

OBJECTIVES: Smaller kidney lesions which are more often detected recently by accidental imaging are amenable for nephron sparing approach whether at open surgery, laparoscopy or ablative techniques. The pretreatment planning is based on multiplanner CT expected to well define the relationship of the lesion to the major renal blood vessels and collecting system (CS). This study is aimed to compare the pre-surgical CT measurements of the distance from tumor to CS to the actual distances observed on radical nephrectomy specimens. PATIENTS AND METHODS: Contrast CT of 39 patients with renal cell carcinoma (RCC) underwent measurements of the distance between CS and renal tumor. All measurements were confronted with the measurements performed on radical nephrectomy specimens of the same patients. RESULTS: Of all 39 patients in 34 (87%) CT showed a contact relation between the tumor and the CS. In fact, the CS involvement has been histologically proven only in three (7.6%) cases. Cutting off the measurements at thresholds of 2 and 5 mm also showed a significant discrepancy between CT and specimen measurements. CONCLUSIONS: The trend of NSS and ablative techniques stressed out the importance of pretreatment measurements of the distance between the tumor and the CS. This study as performed on radical nephrectomy specimens points out the overestimated proximity of the tumor to the CS. These data if confirmed by other studies, may play a role while planning the management of NS approaches.