[Urolithiasis 2016 : Reliable, effective and low radiation exposure]

An enigma: case series of vesical calculi from prolonged and neglected indwelling catheter

Vesical calculus is a common condition with familiar aetiology in our environment as it is obtained in other parts of the world. Notwithstanding, uncommon aetiology of this pathology still exists though rarely encountered especially where out-of-pocket payment is the norm for accessing health care services. This is a report of three patients with varying indications for indwelling vesical catheter insertion via urethral or suprapubic route and who developed vesical calculus from prolonged and neglected indwelling vesical catheter. These cases are indeed an enigma in contemporary surgical patient care. We share our experience in the care of these patients and to underscore the extra role expected of health care providers in adequate patient education, close attention to guidance and counseling during patients' visits to health facilities.

Feasibility study of ultra-low-dose dedicated maxillofacial computed tomography using filter-based spectral shaping in patients with craniofacial trauma: assessment of image quality and radiation dose

Background

In the setting of multiple trauma, radiation exposure is considered a relevant issue because patients may require repeated imaging to evaluate injuries in different body parts. Recently, spectral shaping of the X-ray beam has been shown to be beneficial in reducing radiation exposure. We investigated the clinical feasibility of a tin-filtered 100 kV protocol for the diagnostic use, compared to routine dedicated maxillofacial CT at 120 kVp in patients with craniofacial trauma; we assessed the image quality, radiation dose, and interobserver agreement.

Methods

We retrospectively evaluated 100 consecutive patients who underwent dedicated maxillofacial CT for craniofacial trauma. Fifty patients were examined with a tin-filtered 100 kV protocol performed using a third-generation dual source CT. The other 50 patients were examined with a standard protocol on a different scanner. Two readers independently evaluated image quality subjectively and objectively, and the interobserver agreement was also assessed. CT dose index volume (CTDI_vol) and dose-length product (DLP) were recorded to compare radiation exposure. A quality-control phantom was also scanned to prospectively assess the impact of tin filtration.

Results

All CT scans showed diagnostic image quality for evaluating craniofacial fractures. The tin-filtered 100 kV protocol showed sufficient-to-good image quality for diagnostic use; however, overall image quality and anatomic delineation from the tin-filtered 100 kV protocol were significantly lower than from the standard protocol. Interobserver agreement was moderate to almost perfect (k=0.56-0.85). Image noises in the air, eye globe, and retrobulbar fat were comparable between the two protocols (P>0.05), whereas both signal-to-noise ratio and contrast-to-noise ratio in the eye globe and retrobulbar fat showed a significant difference (P<0.05). The tin-filtered 100 kV protocol showed a significant reduction in radiation dose compared to the standard protocol: CTDI_vol, 3.33 vs. 30.5 mGy (P<0.001); and DLP, 70.70 vs. 669.43 mGy*cm (P<0.001). The phantom study also demonstrated a lower radiation dose for the tin-filter 100 kV protocol compared to the standard protocol.

Conclusions

Dedicated maxillofacial CT using spectral shaping with tin filtration can allow a significant reduction in radiation dose while maintaining sufficient diagnostic image quality, when compared to the standard protocol.

The Comprehensive Complication Index (CCI) for improved reporting of complications in endourological stone treatment

The Clavien-Dindo Classification (CDC) lacks a combined score of multiple complications in one patient. The comprehensive complication index (CCI) circumvents this problem making it a valuable instrument to optimize quality control. We aimed to introduce and validate CCI in the treatment of urolithiasis. 60 day postoperative complications of 327 consecutive patients undergoing percutaneous nephrolitholapaxy (PNL) and ureterorenoscopy (URS) between 2017 and 2019 were retrospectively assessed and graded according to CDC. CCI was calculated for each patient. Overall morbidity scores of CCI and CDC were compared. Correlation analyses between the two scores and length of hospital stay (LOS) were performed. A multivariate analysis was performed to identify predictive factors for complications. Sample size calculation for an imaginary clinical trial was compared between CCI and CDC. A significant difference in overall morbidity between CCI and CDC was revealed for PNL (p < 0.001) and URS (p = 0.001). There was no statistically significant difference in comparing correlations between cumulative CCI and LOS versus non-cumulative CDC and LOS for both cohorts. Operating time > 90 min, maximum stone size, positive preoperative urine culture and PNL type (p < 0.001) were predictive factors for postoperative complications in PNL, while urine culture (p = 0.02) was for URS. Sample size calculation based on CCI resulted in a significant reduction of required patients for PNL (- 48%) and URS (- 84%) compared to CDC. CCI could successfully be validated in endourological stone treatment with the advantage of assessing complications in their entirety compared to CDC. CCI can significantly reduce the required sample size in future clinical trials.