Rectal NeoplasmsNCT04949646
Intraoperative Neuromonitoring of Pelvic Autonomous Nerve Plexus During Total Mesorectal Excision
A study testing Pelvic Intraoperative Neuromonitoring in people with Rectal Neoplasms, run by Larissa University Hospital at 1 site in Greece.
Trial summary
The purpose of this research protocol is the evaluation of the improvement of the anorectal and urogenital urinary function, alongside the postoperative quality of life after the application of pIONM in patients submitted to TME for rectal cancer. Read more about this study
- Who is it for?
- Ages 18 to 90 yearsHealthy volunteers can take part
- Conditions the study is for
- Rectal Neoplasms
- What is being tested?
- Pelvic Intraoperative Neuromonitoring
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 44 participants
- Where
- 1 siteGreece
- Study dates
- 19 Sep 2021to 19 Sep 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 90 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Histologically confirmed rectal cancer
- Surgical resection with TME
- <90 years old
- Signed informed consent
Who cannot join
- Emergency operation
- Presence of pacemaker
- Partial mesorectal excision
- Sepsis or systematic infection
- Physical or mental impairment
- Pregnancy or nursing
- Insufficient preoperative data for the urogenital/ anorectal function
- Lack of compliance with the research process
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Greece1 site, 1 recruiting
- Recruiting
University Hospital of Larissa
Larissa, 41110
Konstantinos Tepetes, Prof, 00302413502804, tepetesk@gmail.com
Anastasios Manolakis, PhD
About this study
The purpose of this research protocol is the evaluation of the improvement of the anorectal and urogenital urinary function, alongside the postoperative quality of life after the application of pIONM in patients submitted to TME for rectal cancer.
Read the detailed description
The introduction of Total Mesorectal Excision (TME) resulted to the improvement of the overall survival and local recurrence rates of rectal cancer patients. However, the associated urogenital and anorectal functional deficit has a significant effect on the postoperative quality of life of the patient. More specifically, the postoperative rates of urogenital and sexual dysfunction that have been reported in the various series, are estimated at the levels of 70% and 90%, respectively. Additionally, TME is associated with the development of the low anterior syndrome (LARS). LARS is characterized by the onset of fecal incontinence, due to injury in the autonomic nerve plexuses that innervate the internal anal sphincter (IAS); who in turn is responsible for the 52-85% anal resting tone. According to a recent study, 38.8% and 33.7% of patients with normal preoperative urogenital function, developed postoperative stool and urine incontinence, respectively.
It becomes apparent that the incidence rates of these complications vary between the various series, mainly due to their small sample size, the lack of comparative data, the short follow up period, the use of non-validated tools and their retrospective design. Several predictive factors of these adverse events have been suggested in the literature, including old age, tumors located less than 12 cm from the anal verge, preoperative radiotherapy and injury to the pelvic autonomous nerves.
The clinical and functional anatomy of the pelvis are quite complex. The inferior hypogastric plexus is formed by the parasympathetic pelvic nerves, deriving from the I2-I4 and the sympathetic hypogastric nerve. It is a neural anatomic structure that carries organ-specific nerve fibers. Visual identification of the plexus is quite difficult, for various reasons, including the complexity of the nerve distribution, the narrow pelvis, the voluminous mesorectum, obesity, previous pelvic operations, neoadjuvant radiotherapy, locally advanced tumors, intraoperative bleeding and the extensive use of diathermy. According to the current literature, identification of the autonomous pelvic plexus is achievable in 72% of cases, whereas partial localization is possible only in 10.7% of patients.
Theoretically, intraoperative neuromonitoring of the pelvic autonomous nerves (pIONM), could quantify intraoperative nerve injuries, while in parallel, contribute to the improvement of the patients' postoperative quality of life. Several pIONM techniques have been described, including intra-urethral and intra-vesical pressure measurements. However, it was found that intermittent neuromonitoring objectifies the macroscopic integrity assessment of the sacral plexus. Recently, a promising technique, based on the simultaneous electromyography of the IAS and bladder manometry was developed, with encouraging results. During pIONM, the surgeon delivers electric stimuli to the autonomic nerve structures through a hand-held stimulator. At the same time, electromyogram changes of the IAS and the external anal sphincter (EAS), alongside intravesical pressure gradients are assessed.
Intraoperative neuromonitoring has been evaluated in several experimental studies. In a recent study, intraoperative simulation of the inferior hypogastric plexus with a bipolar stimulator resulted to the appearance of a measurable and repeatable electromyographic signal from the IAS.
Simultaneous signal processing from the IAS and urinary bladder, improves the, overall, diagnostic accuracy of these techniques. Stabilization of the electrodes outside the surgical field, has been, also, suggested by some researchers. Additionally, experimental studies evaluated the role of pIONM in the minimal invasive TME.
Moreover, the effectiveness of this technique has been a research subject in multiple clinical trials. In another study, where 85 patients underwent TME, after logistic regression, no use of pIONM and neoadjuvant radiotherapy, were identified as independent prognostic factors of postoperative urogenital deficit. Furthermore, the use of pIONM, was associated with a 100% sensitivity and a 96% specificity for the postoperative development of urogenital and anorectal functional complications.
The application of pIONM has been also suggested in the laparoscopic and robotic TME, using specially designed stimulators. In another trial, preservation of the plexus was achieved in 51.7% of patients submitted to a laparoscopic low anterior resection for rectal cancer. During one year follow-up, patients receiving pIONM, displayed a superiority in terms of postoperative urogenital function, as assessed by the IIEF, IPSS and FSFI questionnaires.
- Conditions
- Rectal Neoplasms
- Being tested
- Pelvic Intraoperative Neuromonitoring
- Keywords
- intraoperative, neuromonitoring, pelvic, autonomous, total, mesorectal, excision
- Medical subject headings
- Rectal Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pelvic Intraoperative NeuromonitoringOther
Pelvic Intraoperative Neuromonitoring (pIONM) allows mapping of the pelvic autonomous plexus during total mesorectal excision (TME).
| Study group | Role | What they receive |
|---|---|---|
| pIONM | Experimental | In the experimental group pIONM will be performed intraoperatively. For the implementation of pIONM, a special device, that allows simultaneous monitoring of sphincter signals and bladder manometry, will be introduced. This device will employ the placement of a bipolar electrode in the internal and external anal sphincter. Moreover, another electrode will be placed on the surrounding tissues. For bladder manometry, the catheter will be connected to the pressure sensor, and subsequently to the pIONM monitor. Intraoperatively, depending on the approach (open or laparoscopic), the respective bipolar stimulator will be used.
Prior to the initiation of pIONM, urinary bladder will be drained and filled with 200 ml R/L. The pIONM parameters will be the following: 1-25 milliampere current, 30 Hz frequency and 200 μs monophasic pulses. Receives: Other: Pelvic Intraoperative Neuromonitoring |
| Control | No intervention | In the control group pIONM will not be performed intraoperatively |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in the quality of life of the patient at 3 months postoperatively, based on the SF-36 questionnaire
Change in the quality of life of the patient, at 3 months postoperatively, compared to the respective preoperative measurements, based on the Short Form 36 (SF-36) questionnaire SF-36: Short Form Survey Minimum Value: 0 Maximum Value: 100 Higher scores indicate a better outcome
Measured: Preoperatively, 3 months postoperatively
Secondary outcomes (24)
Operative time
The total operative time will be recorded. Measurement unit: minutes
Measured: Intraoperative period
Intraoperative bleeding
The total intraoperative blood loss volume will be recorded. Measurement unit: mL
Measured: Intraoperative period
Postoperative discharge time
Postoperative time that the patient can be safely discharged. Measurement unit: hours. The patient will be discharged, when it is ensured that is medically safe to be released. In particular, as the exit time of the patient, will be regarded the time that the patient will fulfil the Clinical Discharge Criteria. More specifically, the patient should meet the following : steady vital signs, be oriented, without nausea or vomiting, mobilized with a steady gait, without a significant bleeding
Measured: Maximum time frame 15 days postoperatively
Postoperative complications
Occurrence of postoperative complications (based on Clavien-Dindo classification). If such an episode occurs, then it will be defined as=1 'YES' If such an episode does not occur, then it will be defined as=0 'NO'
Measured: 1 month postoperatively
Negative resection margin
Occurrence of negative resection margin. If such an episode occurs, then it will be defined as=1 'YES' If such an episode does not occur, then it will be defined as=0 'NO'
Measured: 1 month postoperatively
Local recurrence
Occurrence of local recurrence. If such an episode occurs, then it will be defined as=1 'YES' If such an episode does not occur, then it will be defined as=0 'NO'
Measured: 1 year postoperatively
Bladder capacity
Urodynamic assessment. Evaluation of bladder capacity. Measurement unit: ml
Measured: Preoperatively and 2 months postoperatively
Bladder compliance
Urodynamic assessment. Evaluation of bladder compliance. Measurement unit: ml/cm H2O
Measured: Preoperatively and 2 months postoperatively
Detrusor pressure at maximum flow
Urodynamic assessment. Evaluation of detrusor pressure at maximum flow. Measurement unit: cm H2O
Measured: Preoperatively and 2 months postoperatively
Maximum urinary flow rate
Urodynamic assessment. Evaluation of maximum urinary flow rate. Measurement unit: ml/s
Measured: Preoperatively and 2 months postoperatively
Voiding volume
Urodynamic assessment. Evaluation of voiding volume. Measurement unit: ml
Measured: Preoperatively and 2 months postoperatively
Post-void residual
Urodynamic assessment. Evaluation of post-void residual. Measurement unit: ml
Measured: Preoperatively and 2 months postoperatively
Anal canal resting phase pressure
High-resolution Anorectal Manometry assessment. Evaluation of anal canal resting phase pressure. Measurement unit: mmHg
Measured: Preoperatively and 2 months postoperatively
Sphincter zone length
High-resolution Anorectal Manometry assessment. Evaluation of sphincter zone length. Measurement unit: cm
Measured: Preoperatively and 2 months postoperatively
Short squeeze test
High-resolution Anorectal Manometry assessment. Evaluation of short squeeze (5sec) pressure. Measurement unit: mmHg
Measured: Preoperatively and 2 months postoperatively
Long squeeze test
High-resolution Anorectal Manometry assessment. Evaluation of long squeeze (30sec) pressure. Measurement unit: mmHg
Measured: Preoperatively and 2 months postoperatively
Cough test
High-resolution Anorectal Manometry assessment. Evaluation of cough test (0 and 50 ml). If such an episode occurs, then it will be defined as=1 'YES' If such an episode does not occur, then it will be defined as=0 'NO'
Measured: Preoperatively and 2 months postoperatively
Push test
High-resolution Anorectal Manometry assessment. Evaluation of push test (0 and 50 ml). If such an episode occurs, then it will be defined as=1 'YES' If such an episode does not occur, then it will be defined as=0 'NO'
Measured: Preoperatively and 2 months postoperatively
RAIR test
High-resolution Anorectal Manometry assessment. Evaluation of rectoanal inhibitory reflex (RAIR) test (20 and 50 ml). If such an episode occurs, then it will be defined as=1 'YES' If such an episode does not occur, then it will be defined as=0 'NO'
Measured: Preoperatively and 2 months postoperatively
Difference in the quality of life of the patient, based on the SF-36 questionnaire
Difference in the quality of life of the patient, at 6, 12, 24 months postoperatively, compared to the respective preoperative measurements, based on the Short Form 36 (SF-36) questionnaire SF-36: Short Form Survey Minimum Value: 0 Maximum Value: 100 Higher scores indicate a better outcome
Measured: Preoperatively, 6, 12, 24 months postoperatively
Difference in the erectile function of the patient, based on the IIEF questionnaire
Difference in the erectile function of the patient, at 3, 6, 12, 24 months postoperatively, compared to the respective preoperative measurements, based on the International Index of Erectile Function (IIEF) questionnaire IIEF: International Index of Erectile Function Minimum Value: 0 Maximum Value: 5 Higher scores indicate a better outcome
Measured: Preoperatively, 3, 6, 12, 24 months postoperatively
Difference in the sexual function of the patient, based on the FSFI questionnaire
Difference in the sexual function of the patient, at 3, 6, 12, 24 months postoperatively, compared to the respective preoperative measurements, based on the Female Sexual Function Index (FSFI) questionnaire FSFI: Female Sexual Function Index Minimum Value: 2 Maximum Value: 36 Higher scores indicate a better outcome
Measured: Preoperatively, 3, 6, 12, 24 months postoperatively
Difference in the prostate symptoms of the patient, based on the IPSS questionnaire
Difference in the prostate symptoms of the patient, at 3, 6, 12, 24 months postoperatively, compared to the respective preoperative measurements, based on the International Prostate Symptom Score (IPSS) questionnaire IPSS: International Prostate Symptom Score Minimum Value: 0 Maximum Value: 35 Higher scores indicate a worse outcome
Measured: Preoperatively, 3, 6, 12, 24 months postoperatively
Difference in the low anterior syndrome symptoms of the patient, based on the LARS questionnaire
Difference in the low anterior syndrome symptoms of the patient, at 3, 6, 12, 24 months postoperatively, compared to the respective preoperative measurements, based on the Low Anterior Resection Syndrome (LARS) questionnaire LARS: Low Anterior Resection Syndrome Minimum Value: 0 Maximum Value: 42 Higher scores indicate a worse outcome
Measured: Preoperatively, 3, 6, 12, 24 months postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jul 2021
- Study start19 Sep 2021
- Primary completion19 Sep 2027 (estimated)
- Study completion19 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (33)Papers the sponsor has linked to this study.
- Other trials for Rectal NeoplasmsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The study will employ a prospective, parallel randomized-controlled design
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 44 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Larissa University Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- General Hospital of Larissa, University of Thessaly
- Responsible party
- Principal investigator, Perivoliotis Konstantinos, Larissa University Hospital
- Investigators
- Konstantinos Tepetes, Prof, Study director, Department of Surgery, University Hospital of LarissaKonstantinos Perivoliotis, MD, Principal investigator, Department of Surgery, University Hospital of Larissa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04949646
- Sponsor's protocol ID
- PelIONM
- Status last verified
- Sep 2025
- First submitted
- 22 Jun 2021
- Last updated
- 4 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No plan to share individual patient data
Publications
Kauff DW, Kempski O, Koch KP, Huppert S, Hoffmann KP, Lang H, Kneist W. Continuous intraoperative monitoring of autonomic nerves during low anterior rectal resection: an innovative approach for observation of functional nerve integrity in pelvic surgery. Langenbecks Arch Surg. 2012 Jun;397(5):787-92. doi: 10.1007/s00423-011-0900-x. Epub 2012 Feb 15.
PubMed 22350611Kauff DW, Lang H, Kneist W. Risk Factor Analysis for Newly Developed Urogenital Dysfunction after Total Mesorectal Excision and Impact of Pelvic Intraoperative Neuromonitoring-a Prospective 2-Year Follow-Up Study. J Gastrointest Surg. 2017 Jun;21(6):1038-1047. doi: 10.1007/s11605-017-3409-y. Epub 2017 Apr 4.
PubMed 28378317Wallner C, Lange MM, Bonsing BA, Maas CP, Wallace CN, Dabhoiwala NF, Rutten HJ, Lamers WH, Deruiter MC, van de Velde CJ; Cooperative Clinical Investigators of the Dutch Total Mesorectal Excision Trial. Causes of fecal and urinary incontinence after total mesorectal excision for rectal cancer based on cadaveric surgery: a study from the Cooperative Clinical Investigators of the Dutch total mesorectal excision trial. J Clin Oncol. 2008 Sep 20;26(27):4466-72. doi: 10.1200/JCO.2008.17.3062.
PubMed 18802159Kauff DW, Kronfeld K, Gorbulev S, Wachtlin D, Lang H, Kneist W. Continuous intraoperative monitoring of pelvic autonomic nerves during TME to prevent urogenital and anorectal dysfunction in rectal cancer patients (NEUROS): a randomized controlled trial. BMC Cancer. 2016 May 21;16:323. doi: 10.1186/s12885-016-2348-4.
PubMed 27209237Delacroix SE Jr, Winters JC. Voiding dysfunction after pelvic colorectal surgery. Clin Colon Rectal Surg. 2010 Jun;23(2):119-27. doi: 10.1055/s-0030-1254299.
PubMed 21629630Kneist W, Kauff DW, Rahimi Nedjat RK, Rink AD, Heimann A, Somerlik K, Koch KP, Doerge T, Lang H. Intraoperative pelvic nerve stimulation performed under continuous electromyography of the internal anal sphincter. Int J Colorectal Dis. 2010 Nov;25(11):1325-31. doi: 10.1007/s00384-010-1015-5. Epub 2010 Jul 27.
PubMed 20661601Moszkowski T, Kauff DW, Wegner C, Ruff R, Somerlik-Fuchs KH, Kruger TB, Augustyniak P, Hoffmann KP, Kneist W. Extracorporeal Stimulation of Sacral Nerve Roots for Observation of Pelvic Autonomic Nerve Integrity: Description of a Novel Methodological Setup. IEEE Trans Biomed Eng. 2018 Mar;65(3):550-555. doi: 10.1109/TBME.2017.2703951. Epub 2017 May 12.
PubMed 28504930Kauff DW, Koch KP, Somerlik KH, Heimann A, Hoffmann KP, Lang H, Kneist W. Online signal processing of internal anal sphincter activity during pelvic autonomic nerve stimulation: a new method to improve the reliability of intra-operative neuromonitoring signals. Colorectal Dis. 2011 Dec;13(12):1422-7. doi: 10.1111/j.1463-1318.2010.02510.x.
PubMed 21087387Kauff DW, Moszkowski T, Wegner C, Heimann A, Hoffmann KP, Kruger TB, Lang H, Kneist W. Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation. Neurogastroenterol Motil. 2017 Dec;29(12). doi: 10.1111/nmo.13140. Epub 2017 Jul 6.
PubMed 28681496Schiemer JF, Juo YY, Sanaiha Y, Lin AY, Kazanjian K, Lang H, Kneist W. Application of a newly designed microfork probe for robotic-guided pelvic intraoperative neuromapping. J Minim Access Surg. 2019 Apr-Jun;15(2):182-183. doi: 10.4103/jmas.JMAS_12_18.
PubMed 29582794Kauff DW, Koch KP, Somerlik KH, Hoffmann KP, Lang H, Kneist W. Evaluation of two-dimensional intraoperative neuromonitoring for predicting urinary and anorectal function after rectal cancer surgery. Int J Colorectal Dis. 2013 May;28(5):659-64. doi: 10.1007/s00384-013-1662-4. Epub 2013 Feb 26.
PubMed 23440364Grade M, Beham AW, Schuler P, Kneist W, Ghadimi BM. Pelvic intraoperative neuromonitoring during robotic-assisted low anterior resection for rectal cancer. J Robot Surg. 2016 Jun;10(2):157-60. doi: 10.1007/s11701-015-0556-6. Epub 2015 Dec 24.
PubMed 26705113Kneist W, Kauff DW, Naumann G, Lang H. Resection rectopexy--laparoscopic neuromapping reveals neurogenic pathways to the lower segment of the rectum: preliminary results. Langenbecks Arch Surg. 2013 Apr;398(4):565-70. doi: 10.1007/s00423-013-1064-7. Epub 2013 Feb 23.
PubMed 23435617Schiemer JF, Zimniak L, Hadzijusufovic E, Lang H, Kneist W. Novel multi-image view for neuromapping meets the needs of the robotic surgeon. Tech Coloproctol. 2018 Jun;22(6):445-448. doi: 10.1007/s10151-018-1804-3. Epub 2018 Jun 4.
PubMed 29868993Zhou MW, Huang XY, Chen ZY, Li ZY, Zhou YM, Yang Y, Wang ZH, Xiang JB, Gu XD. Intraoperative monitoring of pelvic autonomic nerves during laparoscopic low anterior resection of rectal cancer. Cancer Manag Res. 2018 Dec 31;11:411-417. doi: 10.2147/CMAR.S182181. eCollection 2019.
PubMed 30643466
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intraoperative Neuromonitoring of Pelvic Autonomous Nerve Plexus During Total Mesorectal Excision
- ClinicalTrials.gov ID
- NCT04949646
- Acronym / sponsor ID
- PelIONM
- Conditions
- Rectal Neoplasms
- Keywords
- intraoperative, neuromonitoring, pelvic, autonomous, total, mesorectal, excision
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 44 participants (estimated)
- Lead sponsor
- Larissa University HospitalUniversity, hospital or other
- Collaborators
- General Hospital of Larissa, University of Thessaly
- Study start
- 19 Sep 2021 (actual)
- Primary completion
- 19 Sep 2027 (estimated)
- Study completion
- 19 Sep 2028 (estimated)
- First posted
- 2 Jul 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this research protocol is the evaluation of the improvement of the anorectal and urogenital urinary function, alongside the postoperative quality of life after the application of pIONM in patients submitted to TME for rectal cancer.
Detailed description
The introduction of Total Mesorectal Excision (TME) resulted to the improvement of the overall survival and local recurrence rates of rectal cancer patients. However, the associated urogenital and anorectal functional deficit has a significant effect on the postoperative quality of life of the patient. More specifically, the postoperative rates of urogenital and sexual dysfunction that have been reported in the various series, are estimated at the levels of 70% and 90%, respectively. Additionally, TME is associated with the development of the low anterior syndrome (LARS). LARS is characterized by the onset of fecal incontinence, due to injury in the autonomic nerve plexuses that innervate the internal anal sphincter (IAS); who in turn is responsible for the 52-85% anal resting tone. According to a recent study, 38.8% and 33.7% of patients with normal preoperative urogenital function, developed postoperative stool and urine incontinence, respectively.
It becomes apparent that the incidence rates of these complications vary between the various series, mainly due to their small sample size, the lack of comparative data, the short follow up period, the use of non-validated tools and their retrospective design. Several predictive factors of these adverse events have been suggested in the literature, including old age, tumors located less than 12 cm from the anal verge, preoperative radiotherapy and injury to the pelvic autonomous nerves.
The clinical and functional anatomy of the pelvis are quite complex. The inferior hypogastric plexus is formed by the parasympathetic pelvic nerves, deriving from the I2-I4 and the sympathetic hypogastric nerve. It is a neural anatomic structure that carries organ-specific nerve fibers. Visual identification of the plexus is quite difficult, for various reasons, including the complexity of the nerve distribution, the narrow pelvis, the voluminous mesorectum, obesity, previous pelvic operations, neoadjuvant radiotherapy, locally advanced tumors, intraoperative bleeding and the extensive use of diathermy. According to the current literature, identification of the autonomous pelvic plexus is achievable in 72% of cases, whereas partial localization is possible only in 10.7% of patients.
Theoretically, intraoperative neuromonitoring of the pelvic autonomous nerves (pIONM), could quantify intraoperative nerve injuries, while in parallel, contribute to the improvement of the patients' postoperative quality of life. Several pIONM techniques have been described, including intra-urethral and intra-vesical pressure measurements. However, it was found that intermittent neuromonitoring objectifies the macroscopic integrity assessment of the sacral plexus. Recently, a promising technique, based on the simultaneous electromyography of the IAS and bladder manometry was developed, with encouraging results. During pIONM, the surgeon delivers electric stimuli to the autonomic nerve structures through a hand-held stimulator. At the same time, electromyogram changes of the IAS and the external anal sphincter (EAS), alongside intravesical pressure gradients are assessed.
Intraoperative neuromonitoring has been evaluated in several experimental studies. In a recent study, intraoperative simulation of the inferior hypogastric plexus with a bipolar stimulator resulted to the appearance of a measurable and repeatable electromyographic signal from the IAS.
Simultaneous signal processing from the IAS and urinary bladder, improves the, overall, diagnostic accuracy of these techniques. Stabilization of the electrodes outside the surgical field, has been, also, suggested by some researchers. Additionally, experimental studies evaluated the role of pIONM in the minimal invasive TME.
Moreover, the effectiveness of this technique has been a research subject in multiple clinical trials. In another study, where 85 patients underwent TME, after logistic regression, no use of pIONM and neoadjuvant radiotherapy, were identified as independent prognostic factors of postoperative urogenital deficit. Furthermore, the use of pIONM, was associated with a 100% sensitivity and a 96% specificity for the postoperative development of urogenital and anorectal functional complications.
The application of pIONM has been also suggested in the laparoscopic and robotic TME, using specially designed stimulators. In another trial, preservation of the plexus was achieved in 51.7% of patients submitted to a laparoscopic low anterior resection for rectal cancer. During one year follow-up, patients receiving pIONM, displayed a superiority in terms of postoperative urogenital function, as assessed by the IIEF, IPSS and FSFI questionnaires.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- The study will employ a prospective, parallel randomized-controlled design
| Arm | Type | Receives |
|---|---|---|
| pIONM | Experimental | Other: Pelvic Intraoperative NeuromonitoringIn the experimental group pIONM will be performed intraoperatively. For the implementation of pIONM, a special device, that allows simultaneous monitoring of sphincter signals and bladder manometry, will be introduced. This device will employ the placement of a bipolar electrode in the internal and external anal sphincter. Moreover, another electrode will be placed on the surrounding tissues. For bladder manometry, the catheter will be connected to the pressure sensor, and subsequently to the pIONM monitor. Intraoperatively, depending on the approach (open or laparoscopic), the respective bipolar stimulator will be used. Prior to the initiation of pIONM, urinary bladder will be drained and filled with 200 ml R/L. The pIONM parameters will be the following: 1-25 milliampere current, 30 Hz frequency and 200 μs monophasic pulses. |
| Control | No intervention | –In the control group pIONM will not be performed intraoperatively |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Histologically confirmed rectal cancer
- Surgical resection with TME
- <90 years old
- Signed informed consent
Key exclusion criteria (8 listed)
- Emergency operation
- Presence of pacemaker
- Partial mesorectal excision
- Sepsis or systematic infection
- Physical or mental impairment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pelvic Intraoperative NeuromonitoringPelvic Intraoperative Neuromonitoring (pIONM) allows mapping of the pelvic autonomous plexus during total mesorectal excision (TME). | Other | pIONM |
Primary outcome
Change in the quality of life of the patient at 3 months postoperatively, based on the SF-36 questionnaire
Time frame: Preoperatively, 3 months postoperatively
Change in the quality of life of the patient, at 3 months postoperatively, compared to the respective preoperative measurements, based on the Short Form 36 (SF-36) questionnaire SF-36: Short Form Survey Minimum Value: 0 Maximum Value: 100 Higher scores indicate a better outcome
24 secondary outcomes
Operative time
Time frame: Intraoperative period
Intraoperative bleeding
Time frame: Intraoperative period
Postoperative discharge time
Time frame: Maximum time frame 15 days postoperatively
Postoperative complications
Time frame: 1 month postoperatively
Negative resection margin
Time frame: 1 month postoperatively
Local recurrence
Time frame: 1 year postoperatively
Bladder capacity
Time frame: Preoperatively and 2 months postoperatively
Bladder compliance
Time frame: Preoperatively and 2 months postoperatively
Detrusor pressure at maximum flow
Time frame: Preoperatively and 2 months postoperatively
Maximum urinary flow rate
Time frame: Preoperatively and 2 months postoperatively
Voiding volume
Time frame: Preoperatively and 2 months postoperatively
Post-void residual
Time frame: Preoperatively and 2 months postoperatively
Anal canal resting phase pressure
Time frame: Preoperatively and 2 months postoperatively
Sphincter zone length
Time frame: Preoperatively and 2 months postoperatively
Short squeeze test
Time frame: Preoperatively and 2 months postoperatively
Long squeeze test
Time frame: Preoperatively and 2 months postoperatively
Cough test
Time frame: Preoperatively and 2 months postoperatively
Push test
Time frame: Preoperatively and 2 months postoperatively
RAIR test
Time frame: Preoperatively and 2 months postoperatively
Difference in the quality of life of the patient, based on the SF-36 questionnaire
Time frame: Preoperatively, 6, 12, 24 months postoperatively
Difference in the erectile function of the patient, based on the IIEF questionnaire
Time frame: Preoperatively, 3, 6, 12, 24 months postoperatively
Difference in the sexual function of the patient, based on the FSFI questionnaire
Time frame: Preoperatively, 3, 6, 12, 24 months postoperatively
Difference in the prostate symptoms of the patient, based on the IPSS questionnaire
Time frame: Preoperatively, 3, 6, 12, 24 months postoperatively
Difference in the low anterior syndrome symptoms of the patient, based on the LARS questionnaire
Time frame: Preoperatively, 3, 6, 12, 24 months postoperatively
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Sep 2025.
- Background: PubMed 22350611Kauff DW, Kempski O, Koch KP, Huppert S, Hoffmann KP, Lang H, Kneist W. Continuous intraoperative monitoring of autonomic nerves during low anterior rectal resection: an innovative approach for observation of functional nerve integrity in pelvic surgery. Langenbecks Arch Surg. 2012 Jun;397(5):787-92. doi: 10.1007/s00423-011-0900-x. Epub 2012 Feb 15.
- Background: PubMed 28378317Kauff DW, Lang H, Kneist W. Risk Factor Analysis for Newly Developed Urogenital Dysfunction after Total Mesorectal Excision and Impact of Pelvic Intraoperative Neuromonitoring-a Prospective 2-Year Follow-Up Study. J Gastrointest Surg. 2017 Jun;21(6):1038-1047. doi: 10.1007/s11605-017-3409-y. Epub 2017 Apr 4.
- Background: PubMed 18802159Wallner C, Lange MM, Bonsing BA, Maas CP, Wallace CN, Dabhoiwala NF, Rutten HJ, Lamers WH, Deruiter MC, van de Velde CJ; Cooperative Clinical Investigators of the Dutch Total Mesorectal Excision Trial. Causes of fecal and urinary incontinence after total mesorectal excision for rectal cancer based on cadaveric surgery: a study from the Cooperative Clinical Investigators of the Dutch total mesorectal excision trial. J Clin Oncol. 2008 Sep 20;26(27):4466-72. doi: 10.1200/JCO.2008.17.3062.
- Background: PubMed 27209237Kauff DW, Kronfeld K, Gorbulev S, Wachtlin D, Lang H, Kneist W. Continuous intraoperative monitoring of pelvic autonomic nerves during TME to prevent urogenital and anorectal dysfunction in rectal cancer patients (NEUROS): a randomized controlled trial. BMC Cancer. 2016 May 21;16:323. doi: 10.1186/s12885-016-2348-4.
- Background: PubMed 21629630Delacroix SE Jr, Winters JC. Voiding dysfunction after pelvic colorectal surgery. Clin Colon Rectal Surg. 2010 Jun;23(2):119-27. doi: 10.1055/s-0030-1254299.
- Background: PubMed 20661601Kneist W, Kauff DW, Rahimi Nedjat RK, Rink AD, Heimann A, Somerlik K, Koch KP, Doerge T, Lang H. Intraoperative pelvic nerve stimulation performed under continuous electromyography of the internal anal sphincter. Int J Colorectal Dis. 2010 Nov;25(11):1325-31. doi: 10.1007/s00384-010-1015-5. Epub 2010 Jul 27.
- Background: PubMed 28504930Moszkowski T, Kauff DW, Wegner C, Ruff R, Somerlik-Fuchs KH, Kruger TB, Augustyniak P, Hoffmann KP, Kneist W. Extracorporeal Stimulation of Sacral Nerve Roots for Observation of Pelvic Autonomic Nerve Integrity: Description of a Novel Methodological Setup. IEEE Trans Biomed Eng. 2018 Mar;65(3):550-555. doi: 10.1109/TBME.2017.2703951. Epub 2017 May 12.
- Background: PubMed 21087387Kauff DW, Koch KP, Somerlik KH, Heimann A, Hoffmann KP, Lang H, Kneist W. Online signal processing of internal anal sphincter activity during pelvic autonomic nerve stimulation: a new method to improve the reliability of intra-operative neuromonitoring signals. Colorectal Dis. 2011 Dec;13(12):1422-7. doi: 10.1111/j.1463-1318.2010.02510.x.
- Background: PubMed 28681496Kauff DW, Moszkowski T, Wegner C, Heimann A, Hoffmann KP, Kruger TB, Lang H, Kneist W. Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation. Neurogastroenterol Motil. 2017 Dec;29(12). doi: 10.1111/nmo.13140. Epub 2017 Jul 6.
- Background: PubMed 29582794Schiemer JF, Juo YY, Sanaiha Y, Lin AY, Kazanjian K, Lang H, Kneist W. Application of a newly designed microfork probe for robotic-guided pelvic intraoperative neuromapping. J Minim Access Surg. 2019 Apr-Jun;15(2):182-183. doi: 10.4103/jmas.JMAS_12_18.
- Background: PubMed 23440364Kauff DW, Koch KP, Somerlik KH, Hoffmann KP, Lang H, Kneist W. Evaluation of two-dimensional intraoperative neuromonitoring for predicting urinary and anorectal function after rectal cancer surgery. Int J Colorectal Dis. 2013 May;28(5):659-64. doi: 10.1007/s00384-013-1662-4. Epub 2013 Feb 26.
- Background: PubMed 26705113Grade M, Beham AW, Schuler P, Kneist W, Ghadimi BM. Pelvic intraoperative neuromonitoring during robotic-assisted low anterior resection for rectal cancer. J Robot Surg. 2016 Jun;10(2):157-60. doi: 10.1007/s11701-015-0556-6. Epub 2015 Dec 24.
- Individual participant dataSharing planned: No. No plan to share individual patient data
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Konstantinos Tepetes, Prof study director
Department of Surgery, University Hospital of Larissa
Konstantinos Perivoliotis, MD principal investigator
Department of Surgery, University Hospital of Larissa
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Pelvic Intraoperative Neuromonitoring in people with Rectal Neoplasms, run by Larissa University Hospital at 1 site in Greece.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Konstantinos Tepetes, Prof (00302413502804, tepetesk@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in the quality of life of the patient at 3 months postoperatively, based on the SF-36 questionnaire (time frame: Preoperatively, 3 months postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04949646, which also lists 33 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Sep 2025.