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Updated: May 9, 2026
An Orthotopic Bladder Tumor Model and the Evaluation of Intravesical saRNA Treatment
Published on: July 28, 2012
Trans-resectoscope stimulation predicts the need to block adductor response during bladder tumor resection
Takahiro Mihara1, Hideki Itoh, Kozo Hashimoto
1From the Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama; Department of Anesthesiology, International University of Health and Welfare Atami Hospital, Shizuoka Prefecture; and Department of Anesthesiology, Sagamihara Kyodo Hospital, Kanagawa Prefecture, Japan.
Background:
Obturator nerve block is performed on patients who undergo transurethral resection of inferolateral bladder tumors to prevent thigh adductor muscle contraction. However, other than the tumor site, we have no criteria to judge whether this block is necessary in all patients. Moreover, it is difficult to predict the efficacy of obturator nerve block before resection. To solve these problems, we have devised a trans-resectoscope stimulation technique that involves delivering several single-twitch electrical stimuli to the inside wall of the bladder via a resectoscope to elicit contraction of the thigh adductor muscle.
Methods:
Trans-resectoscope stimulation was performed in 51 cases on 45 patients for which urologists had requested obturator nerve block. If no thigh adductor muscle contraction was observed with trans-resectoscope stimulation (i.e., negative result), tumor resection was performed without further investigation. If the result was positive, we performed obturator nerve block or administered a muscle relaxant until the result turned negative. Positive or negative responses to the initial trans-resectoscope stimulation and thigh adductor muscle contraction during subsequent resection were recorded.
Results:
The initial trans-resectoscope stimulation result was negative in 29 of the 51 cases (57%). In these cases, tumor resection was allowed to proceed, and no thigh adductor muscle contraction occurred (rate of incidence [95% confidence interval]: 0% [0%-5.7%]). In cases with a positive initial trans-resectoscope stimulation result (22/51 or 43%), we performed an obturator nerve block or administered a muscle relaxant after which we once again stimulated to verify the lack of adductor response before proceeding with the resection, and no thigh adductor muscle contraction was observed during resection.
Conclusions:
Trans-resectoscope stimulation is beneficial not only to predict the need to block the contraction of the thigh adductor during tumor resection but also to avoid unnecessary obturator nerve block.
Insights
Trans-resectoscope stimulation effectively predicts the need for obturator nerve blocks during bladder tumor resection. This technique helps avoid unnecessary procedures by identifying patients who do not require the block.
Area of Science:
- Urology
- Surgical Techniques
- Nerve Blocks
Background:
- Obturator nerve block is used during transurethral resection of bladder tumors to prevent thigh adductor muscle contraction.
- Current criteria for necessity and pre-operative efficacy prediction of obturator nerve block are limited.
- A novel trans-resectoscope stimulation technique was developed to address these limitations.
Purpose of the Study:
- To evaluate the utility of trans-resectoscope stimulation in predicting the need for obturator nerve block.
- To determine if this technique can prevent unnecessary obturator nerve blocks.
- To assess the incidence of thigh adductor muscle contraction during tumor resection based on stimulation results.
Main Methods:
- Trans-resectoscope electrical stimulation was applied to the bladder wall in 51 cases.
- If stimulation was negative, tumor resection proceeded without block.
- If stimulation was positive, obturator nerve block or muscle relaxant was administered, followed by re-stimulation.
Main Results:
- Initial trans-resectoscope stimulation was negative in 57% of cases (29/51), with no thigh adductor contraction during resection (0% incidence).
- In 43% of cases (22/51) with positive initial stimulation, blocks or relaxants were administered, and no thigh adductor contraction occurred during resection.
- The technique successfully identified patients not requiring the block and those who did.
Conclusions:
- Trans-resectoscope stimulation is a valuable tool for predicting the necessity of obturator nerve block.
- This method helps avoid unnecessary obturator nerve blocks, improving patient management.
- The technique aids in preventing thigh adductor muscle contraction during bladder tumor resection.
