Accuracy in detecting and measuring residual fragments with the Uro Dyna-CT

Application of DynaCT biliary soft tissue reconstruction technology in diagnosis and treatment of hepatolithiasis

BACKGROUND

Hepatobiliary stone disease involves an intrahepatic bile duct stone that occurs above the confluence of the right and left hepatic ducts. One-step percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) using the percutaneous transhepatic one-step biliary fistulation (PTOBF) technique enables the clearing of intrahepatic stones and the resolution of strictures. However, hepatolithiasis with associated strictures still has high residual and recurrence rates after one-step PTCSL. DynaCT can achieve synchronized acquisition with a flat-panel detector during C-arm rotation. The technical approach and application value of DynaCT biliary soft tissue reconstruction technology for the diagnosis and treatment of hepatolithiasis with bile duct stenosis were evaluated in this study.

AIM

To explore the value of DynaCT biliary soft tissue reconstruction technology for the diagnosis and treatment of hepatolithiasis with bile duct stenosis, and to assess the feasibility and effectiveness of the PTOBF technique guided by DynaCT biliary soft tissue reconstruction technology.

METHODS

The clinical data of 140 patients with complex biliary stenosis disease combined with bile duct stenosis who received PTOBF and were admitted to the First Affiliated Hospital of Guangzhou Medical University from January 2020 to December 2024 were collected. The patients were divided into two groups: DynaCT-PTOBF group (70 patients) and conventional PTOBF group (70 patients). These groups were compared in terms of the preoperative bile duct stenosis, location of the liver segment where the stone was located, intraoperative operative time, immediate stone retrieval rate, successful stenosis dilatation rate, postoperative complication rate, postoperative reoperation rate, stone recurrence rate, and stenosis recurrence rate.

RESULTS

DynaCT biliary soft tissue reconstruction technology was successfully performed in 70 patients. The DynaCT-PTOBF group had a higher detection rate of target bile ducts where bile duct stones and biliary strictures were located than the PTOBF group. Compared with the PTOBF group, the DynaCT-PTOBF group was characterized by a significantly greater immediate stone removal rate (68.6% vs 50.0%, P = 0.025), greater immediate stenosis dilatation success rate (72.9% vs 55.7%, P = 0.034), greater final stenosis release rate (91.4% vs 75.7%, P = 0.012), shorter duration of intraoperative hemorrhage (3.14 ± 2.00 vs 26.5 ± 52.1, P = 0.039), and lower incidence of distant cholangitis (2.9% vs 11.4%, P = 0.49). There were no significant differences between the two groups in terms of the final stone removal rate, reoperation rate, or long-term complication incidence rate.

CONCLUSION

DynaCT biliary soft tissue reconstruction technology guiding the PTOBF technique in patients with hepatolithiasis with bile duct stenosis is feasible and accurate. It may be beneficial for optimizing the preoperative evaluation of the PTOBF technique.

Comparison of endoscopic versus CT assessment of stone-free status after percutaneous nephrolithotomy (PCNL)

This study is aimed to determine whether postoperative low dose computed tomography (LDCT) imaging is necessary after percutaneous nephrolithotomy (PCNL), or the surgeon's intraoperative assessment of residual fragments (RF) is sufficient and avoidance of postoperative imaging with reduction of radiation exposure can be achieved. Data of all 610 patients who underwent PCNL in prone position in our institution from February 2009 to September 2020 was collected. Parameters such as age, gender, BMI, ASA-Classification, stone related parameters and the surgeon's assessment of stone-free status were analyzed. The LDCT performed postoperatively was compared to the intraoperative assessment of the surgeon regarding RF. The mean age of patients was 52.82 years; the mean BMI was 28.18 kg/m2. In 418 cases, the surgeon made a clear statement about the presence of RF and postoperative LDCT was carried out. The discrepancy between the two methods (surgeon´s assessment vs. LDCT) was significant at p < 0.0001. The sensitivity, specificity, positive and negative predictive value of the surgeon when assessing RF were 24.05%, 99.45%, 98.28% and 50%. Stone free rate (SFR) after primary PCNL was 45.57%. The overall SFR at discharge was 96.23%. Although the surgeon´s assessment of RF was reliable, postoperative LDCT imaging should still be performed if endoscopic stone clearance is suspected due to the high false negative rate and the low negative predictive value. The optimal timing of postoperative imaging following PCNL remains unclear.

Carbon Dioxide Pyelography: A Convenient and Safe Alternative to Both Room Air and Iodinated Contrast Pyelography During Endourologic Procedures

Introduction/Background: There are increasing reports of serious complications related to the air pyelography technique, which raise concerns about the safety of room air (RA) injection into the renal collecting system. Carbon dioxide (CO2) is much more soluble in blood than nitrogen and oxygen and thus considerably less likely to cause gas emboli. Iodinated contrast medium (ICM) is expensive, and supplies may not be as reliable as previously assumed. CO2 pyelography (CO2-P) techniques using standard fluoroscopy and digital subtraction fluoroscopy (CO2 digital subtraction pyelography [CO2-DSP]) are described. Materials and Methods: During the endourologic stone cases, 15 to 20 mL of CO2 gas was typically injected into the renal pelvis through a catheter or sheath. Imaging was usually obtained with endovascular CO2 digital subtraction angiography settings using either a traditional fluoroscopy system (TFS) or robotic arm multiplanar fluoroscopy system (RMPFS) (Artis Zeego Care+Clear®; Siemens). Results: CO2-P was performed in 22 endoscopic stone treatment cases between March 2021 and August 2022, primarily using digital subtraction settings in 20 cases. CO2-DSP overall provided higher quality images of the renal pelvis and collecting system than CO2-P, but with a relatively higher radiation dose. Following a quality intervention, fluoroscopy doses for CO2-DSP cases were decreased by 81% overall. The use of CO2-P avoided fluoroscopic or intraoperative CT (ICT) artifacts seen with intraluminal ICM. Conclusions: CO2-P allows the urologist to obtain imaging of the renal collecting system without ICM and with much lower risk of air embolism compared with RA pyelography. CO2 is a nearly cost-free alternative to ICM. Because CO2 is widely available and the technique is easy to perform, we propose that CO2-P should be favored over traditional air pyelography to improve patient safety.

Percutaneous Nephrolithotomy with Intraoperative Computed Tomography Scanning Improves Stone-Free Rates

Introduction: The use of fluoroscopy during percutaneous nephrolithotomy (PCNL) may lead to an overestimation of stone-free rates. The objective of this study is to demonstrate the feasibility of intraoperative CT-guided PCNL compared with standard of care (SoC) PCNL. Patients and Methods: A prospective feasibility study (20 patients undergoing PCNL with an intraoperative CT scan between June 2017 and February 2020) and a retrospective study of a historical cohort (20 consecutive patients undergoing SoC PCNL between September 2015 and September 2016) were conducted. All procedures were performed by an expert endourologist in a tertiary referral hospital. Follow-up was performed at 6 weeks postoperatively. The primary goal is to investigate the practicality and potential benefits and harms of intraoperative CT scanning during PCNL. Secondary outcomes are a stone-free rate after the 6-week follow-up, perioperative radiation exposure, the need for postoperative imaging, and peri- and postoperative complications. Statistical significance was considered at p < 0.05. Results: The initial stone-free rate in the CT scan group was 65% (n = 13). In 25% (n = 5) of patients, residual stone fragments were removed after the perioperative CT scan. In the SoC group, 85% (n = 17) of patients were thought to be stone free perioperatively. At the 6-week follow-up, 80% (n = 16) in the CT scan group vs 50% in the SoC group (n = 10) were found to be stone free. Radiation exposure, perioperatively, was higher in the CT scan group. Complications were comparable between groups. Limitations of the study are the nonrandomized design of the study and nonstandardized follow-up imaging. Conclusions: Intraoperative CT scanning during PCNL is feasible and gives a better estimate of any remaining stone fragments compared with fluoroscopy only.

Use of the Uro Dyna-CT in endourology - the new frontier

We describe the use of the Uro Dyna-CT, an imaging system used in the operating room that produces real-time three-dimensional (3D) imaging and cross-sectional image reconstructions similar to an intraoperative computerized tomography, during a percutaneous nephrolithotomy and a contralateral flexible ureteroscopy in a complete supine position. A 65 year-old female patient had an incomplete calyceal staghorn stone in the right kidney and a 10mm in the left one. The procedure was uneventful and the intraoperative use of the Uro Dyna-CT identified 2 residual stones that were not found by digital fluoroscopy and flexible nephroscopy at the end of surgery, helping us to render the patient stone-free in one procedure, which was confirmed by a postoperative CT scan. Prospective studies will define the real role of the Uro Dyna-CT for endourological procedures, but its use seems to be a very promising tool for improving stone free rates and decreasing auxiliary procedures, especially for complex cases.