Noninvasive, in vivo assessment of the cervical microcirculation using incident dark field imaging.

AIM: This study evaluates the feasibility of handheld vital microscopy for noninvasive, objective assessment of the microcirculation of the human uterine cervix. We qualitatively and quantitatively describe the microcirculation in healthy subjects in order to provide a basis for its application in cervical pathology. METHODS: Incident dark field imaging was used to image the microcirculation in four quadrants of the uterine ectocervix in ten healthy participants. If the squamocolumnar junction was visible, measurements were repeated on the endocervical columnar epithelium as well. Image acquisition time was recorded and participants scored the experienced level of discomfort. Angioarchitecture was classified according to Weber's classification. Quantitative parameters included capillary density (CD), total and perfused vessel density (TVD, PVD), proportion of perfused vessels (PPV) and microvascular flow index (MFI). RESULTS: Image acquisition was easy, fast and well tolerated. Angioarchitecture was characterized by two distinctive and organized patterns; capillary loops underneath the squamous epithelium of the ectocervix and vascular networks underneath the columnar epithelium. In the image sequences containing capillary loops, mean CD was 33.2 cpll/mm2 (95% CI 28.2-38.2 cpll/mm2). In the image sequences with vascular networks, mean TVD was 12.5 mm/mm2 (95% CI 11.2-13.77 mm/mm2), mean PVD was 12.2 (95% CI 11.0-13.5 mm/mm2), MFI was 3 and PPV was 100%. CONCLUSIONS: Incident dark field imaging allows for noninvasive, real time visualization and objective evaluation and quantification of the microcirculation of the uterine cervix. The organized vascular patterns and optimal perfusion observed in healthy subjects allow for comparison with cervical pathology, for example in patients with cervical dysplasia or cervical cancer.

Laparoscopic renal cryoablation using ultrathin 17-gauge cryoprobes: mid-term oncological and functional results.

UNLABELLED: Study Type - Therapy (case series). LEVEL OF EVIDENCE: 4. What's known on the subject? and What does the study add? Laparoscopic Cryoablation of renal masses has a low persistence and recurrence rates at short term follow-up albeit higher than Partial Nephrectomy. Long term results are scarcely reported. It is however a NSS technique suitable for high-risk that preserves renal function. The study provides (1) mid-term oncological outcomes of laparoscopic cryoablation of renal masses stratified by primary pathology (RCC, benign mass or undetermined biopsy) and (2) data on renal function evolution up to one year of follow-up supporting the fact that the only predictor of (moderate)renal insufficiency development after Laparoscopic cryoablation is the eGFR at baseline. OBJECTIVE: To present the functional and oncological mid-term results of laparoscopic cryoablation of renal masses using third generation ultrathin (17-gauge[G]) cryoprobes. PATIENTS AND METHODS: • Consecutive patients with small renal masses treated by cryoablation from September 2003 to September 2008 were prospectively evaluated. The cryoablation was performed using multiple third generation 17-G cryoprobes after intraoperative mass biopsy. • Data on serum creatinine measurements and cross sectional imaging (computed tomography/magnetic resonance imaging) were regularly collected according to a previously determined protocol. Follow-up was censored in October 2009. • Renal function analysis was based on estimated glomerular filtration rate (eGFR) at 1 year compared with baseline. Residual (or persistent tumour) and recurrence were defined as the presence of residual enhancement at first follow-up and 'de novo' enhancement of a non-enhancing cryolesion at any time during follow-up. • Survival data were analysed using the Kaplan-Meier method. Best estimates for the overall survival (OS), recurrence-free survival (RFS), cancer-specific survival (CSS) and metastatic-free survival (MFS) were made for patients with renal cell carcinoma (RCC) and for patients with RCC or non-diagnostic biopsy. RESULTS: • A total of 92 patients (100 tumours; mean size 2.5 ± 0.8 cm) were treated in 95 sessions. The mean follow-up was 30.2 ± 16.6 months (Mean values are ±SD). • Intraoperative biopsy showed RCC in 51 patients (53.7%), benign lesion in 23 patients (24.2%) and was non-diagnostic in 21 patients (22.1%). Three tumour persistences and four radiological recurrences were detected. • The estimated mean RFS time and 3-year OS and RFS in patients with RCC exclusively were 47.8 (95% confidence interval [CI]: 44.1-51.1) months, 86.1% (95% CI: 71.2-93.6) and 91.8% (95% CI: 76.3-97.3), respectively. The figures were slightly higher in the group of patients with RCC or unknown pathology. The actual CSS and MFS rates were 100%. • Renal function was preserved in 84.5% of patients with normal preoperative eGFR. • Baseline eGFR was the only predictor of renal insufficiency development at 1-year follow-up. CONCLUSION: Laparoscopic cryoablation with multiple ultrathin cryoprobes is oncologically and functionally effective at mid-term follow-up.

The performance of 17-gauge cryoprobes in vitro.

In cryosurgery it is crucial that the performance of cryoprobes is predictable and constant. In this study we tested the intra- and interneedle variation between 17-gauge cryoprobes in two homogeneous mediums. Also, a multiprobe setup was tested. Cryoprobe performance was defined as the time it takes one cryoprobe to lower the temperature from 0 to -20 degrees C as measured by four thermosensors each at 3 mm distance from the cryoprobe. In agar eight cryoprobes were tested during six freeze cycles, and in gel four cryoprobes during four freeze cycles; each freeze cycle in a different cup of agar or gel. Using more accurate 'bare' thermosensors three cryoprobes were tested in gel during two freeze cycles. A multiprobe configuration with four cryoprobes was tested during two freeze cycles in both agar and gel. Statistical analyses were done using ANOVA for repeated measures. There was no significant intraneedle variation, whereas both in agar and gel there was a significant interneedle variation (p<0.05). Mean performance in gel was better than in agar (p<0.001). Also, there was a significant variation between the four thermosensors (p<0.001). Using bare thermosensors mean performance was 2.7 times faster compared to measurements by regular thermosensors (p<0.001). In a multiprobe configuration, overall performance seems less variable and more reproducible compared to a single cryoprobe. In conclusion, the performance of cryoprobes differs depending on the medium and measuring device used. Cryoprobes deliver reproducible freeze cycles, although there is variation between different cryoprobes. In a multiprobe configuration performance seems less variable.

Are there parameters that predict a nondiagnostic biopsy outcome taken during laparoscopic-assisted cryoablation of small renal tumors?

BACKGROUND AND PURPOSE: The histopathologic diagnosis of a small renal mass (SRM) that is managed with cryoablation relies on preoperative or intraoperative biopsies. Because a considerable number of these SRMs are benign, accurate diagnosis has prognostic and follow-up implications. The main problem in SRMs is the high rate of nondiagnostic biopsies. Our purpose was to assess whether certain tumor and biopsy characteristics are correlated with a diagnostic biopsy outcome. PATIENTS AND METHODS: One hundred tumors that were smaller than 4.5 cm in 94 patients were managed with laparoscopic cryoablation. After dissection of the perirenal fat and identification of the tumor by intra-abdominal ultrasonography, one or more biopsies were obtained before freezing. Using the Student t/Mann Whitney U test, the following parameters were evaluated for predicting biopsy outcome: Tumor size, location, and exophytic part of the tumor, size of the biopsy needle, the number of biopsies taken, and presence of nonenhancing areas compatible with necrosis inside the tumors. Correlations among parameters were assessed using a Spearman correlation or Kruskal-Wallis test. RESULTS: Twenty-two (22%) biopsies were nondiagnostic and consisted of normal kidney tissue, connective tissue, fat, fibrosis, necrosis, and/or blood. There were no significant differences in parameters between the diagnostic and nondiagnostic group. There was a positive correlation between tumor size and number of biopsies (P=0.029) and between the presence of nonenhancing areas and both size (P<0.001) and the number of biopsies taken (P<0.001). CONCLUSION: No statistical significant correlation was found between biopsy outcome and tumor or biopsy characteristics. More biopsies were taken in larger tumors, and larger tumors contained more nonenhancing areas that were suspect for necrosis.

Quality of life and perceived pain after laparoscopic-assisted renal cryoablation.

PURPOSE: Assessing changes in quality of life (QoL) and perceived pain after laparoscopic-assisted cryoablation (LAC) of renal tumors. PATIENTS AND METHODS: Data for 57 patients who were treated with LAC were prospectively collected. QoL, divided into various domains, and postoperative pain were assessed using the Medical Outcome Study 36-item Short Form Health Survey (SF-36), the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC-QLQ-C30), and Visual Analog Scale (VAS). Assessment was performed at baseline and at different time intervals until 1 year after LAC. Using a repeated measures analysis of variance, the influence of the following parameters was evaluated: Time of assessment, age, comorbidity, the occurrence of a complication, and tumor histology. RESULTS: SF-36: At baseline, only general health perceptions scored lower compared with the general population. Time of assessment and a complication did not affect QoL. Comorbidity and age >70 years led to a significantly lower QoL. Tumor histology affected general health perceptions. EORTC-QLQ-C30: Time of assessment affected 7 of 15 domains because of lower scores after 2 weeks. Age and comorbidity each negatively influenced five domains. A complication increased three symptoms scores and lowered general health status. Tumor histology significantly altered role functioning. VAS: VAS reached a peak 1 day after LAC, then quickly declined. Patients >70 years had significant higher VAS. CONCLUSIONS: QoL of patients who were treated with LAC showed a decrease 2 weeks after surgery but normalized to baseline within 3 months. Age and comorbidities especially affected QoL negatively. The VAS showed a peak 1 day after LAC and then quickly declined.