Researchers tested a new way to create a urinary pouch (called a conduit) during bladder removal surgery. They compared a newer retrosigmoid method to the traditional approach in 303 patients. After following patients for about two years, both methods had similar rates of blockages in the tubes connecting the kidneys to the pouch (around 4-7%). The new method worked safely without causing more kidney or metabolic problems, making it a reasonable option when surgeons need to remove more of the ureter, but it didn’t provide the blockage reduction doctors had hoped for.

The Quick Take

  • What they studied: Whether a newer surgical technique for creating a urinary pouch (retrosigmoid conduit) could reduce blockages in the kidney tubes compared to the traditional method
  • Who participated: 303 patients undergoing bladder removal surgery at multiple hospitals between 2020-2022. Most patients completed their assigned surgery, with follow-up lasting about 2 years
  • Key finding: The newer retrosigmoid method had a 4.1% blockage rate versus 6.7% with the traditional method—a difference that wasn’t statistically significant (P = 0.31), meaning it could be due to chance
  • What it means for you: If you need bladder removal surgery, both methods appear equally safe regarding blockage risk. The newer technique may be preferred when surgeons need to remove more of the ureter, but don’t expect it to dramatically reduce blockage complications

The Research Details

This was a randomized controlled trial, considered the gold standard for medical research. Researchers randomly assigned 303 patients to receive either the newer retrosigmoid ileal conduit or the traditional conduit during robot-assisted bladder removal surgery. The study took place across multiple hospitals between May 2020 and August 2022. Patients were followed for a median of about 2 years (754 days) to track complications. The analysis included 148 patients in the new method group and 149 in the traditional group, with very high completion rates (92-97%).

Randomized controlled trials are the most reliable way to compare two surgical techniques because random assignment reduces bias. By following patients for two years, researchers could identify blockages that develop over time. This study design allows doctors to make confident recommendations about which surgical approach is safer

This study has several strengths: it was randomized (reducing bias), included nearly 300 patients (providing reliable results), had high completion rates, and followed patients for nearly two years. The study was published in a reputable journal (BJU International). However, the relatively modest blockage rates mean the study had good statistical power to detect differences if they existed

What the Results Show

The main finding was that blockage rates were similar between both groups. In the newer retrosigmoid group, 4.1% of patients developed blockages (6 out of 148), while 6.7% in the traditional group developed blockages (10 out of 149). This 2.6% difference was not statistically significant (P = 0.31), meaning researchers cannot confidently say one method is better than the other for preventing blockages. The researchers also measured kidney function using creatinine clearance tests and found no significant differences between groups, suggesting both methods preserved kidney health equally well.

The study examined metabolic complications—problems with body chemistry that can occur after this type of surgery. Vitamin B12 deficiency and metabolic acidosis (when blood becomes too acidic) occurred at similar rates in both groups. This is important because it shows the newer technique didn’t introduce new safety concerns. The high surgical completion rates (92-97%) indicate both procedures were technically feasible

Previous research suggested the retrosigmoid approach might reduce blockages by changing the angle of the kidney tube connections. This study’s results suggest that theoretical advantage doesn’t translate to meaningful clinical improvement. The findings align with other recent surgical research showing that anatomical changes alone don’t always prevent complications

The blockage rates were lower than some researchers expected, which means the study may have had limited ability to detect smaller differences between methods. The study followed patients for about 2 years, but some blockages develop later. The study included patients from multiple hospitals, which is good for generalizability but can introduce variability. Additionally, this was a specialized procedure at experienced centers, so results may not apply to all hospitals

The Bottom Line

For patients needing bladder removal surgery: Both the retrosigmoid and traditional conduit methods appear equally safe regarding blockage prevention (moderate confidence). The retrosigmoid method may be preferred when surgeons need to remove extensive portions of the ureter, as it’s technically feasible and safe (moderate confidence). Discuss with your surgeon which approach is best for your specific situation

This research is relevant for patients with bladder cancer or other conditions requiring bladder removal surgery. Urologists and surgeons should consider this when choosing surgical techniques. Patients should know both methods are safe options. This doesn’t apply to patients with other urinary conditions not requiring bladder removal

Blockages typically develop within the first 1-2 years after surgery, though some can occur later. Kidney function changes may be apparent within weeks to months. Metabolic complications can develop gradually over months to years

Want to Apply This Research?

  • If you’ve had this surgery, track kidney function markers (creatinine and estimated glomerular filtration rate) every 3-6 months. Log any urinary symptoms like decreased output, fever, or back pain that might indicate blockages
  • Set reminders for regular follow-up appointments with your urologist. Monitor fluid intake and output daily. Report any changes in urinary patterns immediately to your healthcare provider
  • Establish a long-term tracking system with your medical team including: quarterly kidney function tests for the first 2 years, then annually; annual imaging if symptoms develop; regular metabolic panels to check for vitamin B12 and acid-base balance; symptom diary for urinary changes

This research summary is for educational purposes and should not replace professional medical advice. If you have bladder cancer or need bladder removal surgery, discuss these findings with your urologist or surgeon who can evaluate your individual situation. Treatment decisions should be based on your specific medical condition, overall health, and surgeon expertise. Always consult qualified healthcare providers before making medical decisions.