An interventional study of Ultrasound-guided intertransverse process block and Ultrasound-guided erector spinae plane block in Kidney Stones, Urolithiasis, Hypocitraturia and Pain, Postoperative, sponsored by Beijing Tsinghua Chang Gung Hospital. Not yet recruiting at 1 site in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by Beijing Tsinghua Chang Gung Hospital · Not applicable, Interventional, and Treatment
Percutaneous nephrolithotomy (PCNL) is the preferred minimally invasive procedure for renal stones larger than 2 cm, staghorn calculi and complex stone burdens, but it is frequently associated with moderate-to-severe postoperative pain arising from the incision, renal capsular distension and visceral or stent-related sources. Truncal fascial plane blocks are a key component of opioid-sparing Enhanced Recovery After Surgery (ERAS) pathways. The erector spinae plane block (ESPB) has accrued supportive evidence in PCNL, whereas the intertransverse process block (ITPB) - whose injectate target, the retro-superior costotransverse ligament space, lies closer to the paravertebral space than the ESPB target - has not been directly compared with ESPB in any urological surgery. This is a single-centre, prospective, stratified block-randomised, triple-blind, parallel-group superiority trial. A total of 140 patients undergoing elective unilateral PCNL under general anaesthesia will be randomised 1:1 to receive either ultrasound-guided ITPB or ESPB at the T10-T11 level before induction of anaesthesia, each with 20 mL of 0.375% ropivacaine (75 mg). Both groups will receive an identical intravenous patient-controlled analgesia (PCA) regimen (sufentanil 200 ug in 100 mL, 2 ug/mL; 1 mL bolus, 15-min lockout, no background infusion) for 48 h, with intravenous flurbiprofen axetil 50 mg as rescue. The primary outcome is cumulative opioid consumption over the first 48 postoperative hours, expressed as oral morphine equivalents (OME), calculated as OME (mg) = total sufentanil consumption (ug) x 3. The key secondary outcome is the area under the curve (AUC) of resting pain numeric rating scale (NRS) scores from 0 to 48 h. The hypothesis is that ITPB is superior to ESPB (that is, lower 48-h OME), with an expected between-group difference of -12 mg OME.
BACKGROUND AND RATIONALE. Percutaneous nephrolithotomy (PCNL) generates moderate-to-severe mixed somatic and visceral pain that peaks within the first 24 to 48 postoperative hours. Fascial plane blocks are central to opioid-sparing ERAS pathways in urology. The erector spinae plane block (ESPB) has supportive evidence in PCNL. The intertransverse process block (ITPB) targets the retro-superior costotransverse ligament (retro-SCTL) space, which lies closer to the paravertebral space than the ESPB target and may therefore provide better visceral analgesia. No randomised trial has directly compared ITPB with ESPB in PCNL or in any urological procedure. OBJECTIVES AND HYPOTHESIS. Primary objective: to determine whether a single preoperative ITPB is superior to ESPB in reducing cumulative 48-hour opioid consumption. H0: mu_ITPB minus mu_ESPB is greater than or equal to 0. H1: mu_ITPB minus mu_ESPB is less than 0. DESIGN. Single-centre, prospective, parallel-group, stratified block-randomised, triple-blind, superiority trial. Stratification by ASA physical status (I-II versus III) and stone complexity (complex, that is staghorn, cast or multiple calculi, versus non-complex, that is single calculus under 2 cm). Within each stratum, permuted blocks of 4 or 6 allocate participants 1:1. The sequence is generated by an independent statistician using a fixed-seed computer algorithm and concealed in sequentially numbered opaque envelopes held by a designated investigator (Zhifeng Gao) who is not involved in block performance, outcome assessment, data entry or follow-up. Envelopes are opened in numerical order after enrolment and baseline assessment; allocation is communicated only to the block operator. BLINDING. Participants, outcome assessors (postoperative pain assessors) and the data analyst are blinded to allocation. The principal investigator and the block operator cannot be blinded because the two techniques require different needle trajectories, but they take no part in postoperative assessment, follow-up or data analysis. To reduce indirect unblinding, all blocks are performed in a separate preparation room with the patient behind a screen, a standard transparent dressing covers the puncture site, the site is fully covered during assessment, assessors do not ask about the procedure, and patients are instructed not to disclose procedural details. INTERVENTIONS. Both blocks are performed before induction of general anaesthesia with the patient prone, using a high-frequency linear probe (6 to 13 MHz) in a transverse orientation at T10-T11 on the operative side, with 20 mL of 0.375 percent ropivacaine (75 mg). The ITPB is performed in-plane through the intertransverse space, with the needle tip advanced through the superior costotransverse ligament into the retro-SCTL space and injectate given in aliquots with re-aspiration every 5 mL. The ESPB is performed in-plane from the lateral end of the probe with the needle tip placed in the fascial plane between the transverse process tip and the erector spinae muscle. Both groups then receive identical general anaesthesia and identical intravenous patient-controlled analgesia with sufentanil 200 ug in 100 mL (2 ug/mL; 1 mL bolus, 15-minute lockout, no background infusion) for 48 hours, with intravenous flurbiprofen axetil 50 mg as rescue (not counted as OME). OUTCOMES AND FOLLOW-UP. Assessments are performed at 2, 6, 12, 24, 48 and 72 hours after surgery by blinded assessors; visceral pain is assessed at 6, 12, 24 and 48 hours; dermatomal sensory extent is tested by cold sensation at 24 hours; satisfaction is recorded before discharge. SAMPLE SIZE. n = 2(Z_alpha/2 + Z_beta)\^2 sigma\^2 / delta\^2 with a two-sided alpha of 0.05, 90 percent power, sigma of 20 mg OME and delta of minus 12 mg OME, giving 58.4 per group; allowing for 15 percent dropout gives 68.7, rounded up to 70 per group (140 total). Because the assumed sigma derives from 24-hour rather than 48-hour data, a blinded re-estimation of sigma is planned once approximately 35 participants per group have been recruited. STATISTICAL ANALYSIS. Primary analysis by ANCOVA with 48-hour OME as the dependent variable and stratification factors, operative duration and BMI as covariates; superiority is declared if the upper limit of the two-sided 95 percent confidence interval for the between-group difference is below 0 and P is below 0.05, with Wilcoxon rank-sum testing as a sensitivity analysis. Repeated NRS measures are analysed with GEE or mixed-effects models. The primary analysis set is per-protocol with intention-to-treat as sensitivity analysis; multiple imputation (M equals 5) is used when missingness reaches 5 percent or more. Analyses are performed in SPSS 26.0.
509 studies on the registry are indexed under Kidney Calculi; 146 are open to participants now.
This study's planned enrollment of 140 is above the median of 86 across 391 interventional studies indexed under Kidney Calculi.
Browse Kidney Calculi studies →Beijing Tsinghua Chang Gung Hospital is the lead sponsor of 108 studies on the registry; 56 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Washout period
A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants allocated to this arm receive a single-shot ultrasound-guided intertransverse process block at the T10-T11 level with 20 mL of 0.375% ropivacaine, performed after induction of general anaesthesia and before surgical positioning. All participants receive identical standardised general anaesthesia, patient-controlled intravenous analgesia with sufentanil and rescue analgesia with intravenous flurbiprofen.
Procedure: Ultrasound-guided intertransverse process block
Participants allocated to this arm receive a single-shot ultrasound-guided erector spinae plane block at the T10-T11 level with 20 mL of 0.375% ropivacaine, performed after induction of general anaesthesia and before surgical positioning. All participants receive identical standardised general anaesthesia, patient-controlled intravenous analgesia with sufentanil and rescue analgesia with intravenous flurbiprofen.
Procedure: Ultrasound-guided erector spinae plane block
Single-shot ultrasound-guided intertransverse process block performed after induction of general anaesthesia and before surgical positioning. Under real-time ultrasound guidance a 22-G echogenic needle is advanced in-plane to the intertransverse space at the T10-T11 level and, after negative aspiration, 20 mL of 0.375% ropivacaine is injected. All participants additionally receive a standardised general anaesthetic and postoperative patient-controlled intravenous analgesia with sufentanil, with intravenous flurbiprofen as rescue analgesia.
Also known as: ITPB
Single-shot ultrasound-guided erector spinae plane block performed after induction of general anaesthesia and before surgical positioning. Under real-time ultrasound guidance a 22-G echogenic needle is advanced in-plane in a cranio-caudal direction to the plane deep to the erector spinae muscle at the T10-T11 level and, after negative aspiration, 20 mL of 0.375% ropivacaine is injected. All participants additionally receive a standardised general anaesthetic and postoperative patient-controlled intravenous analgesia with sufentanil, with intravenous flurbiprofen as rescue analgesia.
Also known as: ESPB
Cumulative opioid consumption within 48 hours after surgery, expressed as oral morphine equivalents (OME)
Cumulative amount of opioid consumed from the end of surgery through 48 hours postoperatively, expressed as oral morphine equivalents (mg OME). Only sufentanil delivered by the patient-controlled intravenous analgesia device is counted and is converted to OME using standard equianalgesic conversion tables. Intravenous flurbiprofen axetil given as rescue analgesia is a non-opioid and is not counted. Any additional opioid administered during or after surgery is converted and included in the total.
Time frame: From the end of surgery to 48 hours after surgery
Area under the curve (AUC) of resting pain NRS scores from 0 to 48 hours after surgery
Area under the curve of resting pain intensity calculated by the trapezoidal rule from numerical rating scale (NRS, 0 to 10) scores recorded at 2, 6, 12, 24 and 48 hours after surgery. Higher values indicate greater cumulative pain intensity.
Time frame: 0 to 48 hours after surgery
Resting, movement-evoked and visceral pain NRS scores
Pain intensity assessed with an 11-point numerical rating scale (NRS, 0 = no pain, 10 = worst imaginable pain) at rest, on movement (turning in bed, coughing) and as visceral pain (deep dull or dragging pain arising from the renal capsule and ureteric stent). Resting and movement-evoked pain are assessed at 2, 6, 12, 24, 48 and 72 hours; visceral pain is assessed at 6, 12, 24 and 48 hours.
Time frame: 2, 6, 12, 24, 48 and 72 hours after surgery
Time to first request for rescue analgesia
Time from completion of the block procedure to the first request for rescue analgesia, used as a surrogate measure of the duration of analgesia.
Time frame: From completion of the block procedure to 72 hours after surgery
Onset time and dermatomal extent of sensory block
Onset time is the interval from injection of local anaesthetic to a demonstrable reduction in cold sensation, assessed 30 minutes after the block in the awake participant. The dermatomal extent of sensory block is mapped once at 24 hours after surgery using cold stimulation and is recorded as the blocked dermatomal levels.
Time frame: 30 minutes after the block procedure; 24 hours after surgery
Incidence of adverse events
Occurrence of postoperative nausea and vomiting, puncture-related complications (haematoma, pneumothorax, infection), systemic local anaesthetic toxicity and non-steroidal anti-inflammatory drug-related adverse reactions (gastrointestinal discomfort, bleeding). Timing, severity, management and outcome are recorded for each event.
Time frame: From the block procedure through 72 hours after surgery
Patient satisfaction with postoperative analgesia
Satisfaction with postoperative pain treatment assessed before discharge using a 5-point Likert scale (very dissatisfied, dissatisfied, neutral, satisfied, very satisfied).
Time frame: Before hospital discharge, an average of 3 days after surgery
Plan to share: Yes — De-identified individual participant data for all variables that underlie the results reported in the primary publication will be shared. Data will be de-identified by removal of name, hospital number and any other direct identifiers; participants will be identified only by a study number.
Supporting information: Study protocol
Time frame: Data will become available 12 months after publication of the primary results and will remain available for 36 months thereafter.
Access criteria: Data will be made available to qualified researchers whose proposed use has been approved by the study investigators and by the Ethics Committee of Beijing Tsinghua Chang Gung Hospital. Requests must be submitted in writing to the principal investigator (whta01956@btch.edu.cn), must state the research question and analysis plan, and require a signed data access agreement before release.
Start is estimated for Dec 2026; primary completion for May 2028, 17 months later.
Of 183 non-industry interventional studies with no phase under Kidney Calculi, half reached primary completion within 31 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 54. This study's planned 17 months is below that.
Counting every sponsor, half of 199 studies reached it within 26 months; a quarter within 12 and three quarters within 51.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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