Comparison of Outcomes and Surgical Time Between Cortical and Medullary Suture vs. Medullary-Only Suture: Cortex Clinical Trial

Official title

Comparison of Outcomes and Surgical Time Between Cortical and Medullary Suture vs. Medullary-Only Suture: Cortex Clinical Trial, From 2025 to 2027

Overview

Renal function preservation is a growing concern in the surgical management of kidney tumors, particularly with the rise in chronic kidney disease worldwide. Recent surgical innovations have focused on modifying renorrhaphy techniques to minimize renal damage. Emerging evidence suggests that omitting cortical suturing may reduce operative time, blood loss, and renal parenchymal loss without increasing major complications. This randomized controlled trial aims to compare outcomes between medullary-only and combined cortical-medullary suture techniques during robot-assisted partial nephrectomy, with the goal of identifying the approach that best balances functional preservation and surgical safety.

Detailed description

To investigate the clinical impact of a potentially modifiable surgical variable, namely, the choice of suture technique during renal reconstruction, on patient outcomes following robot-assisted partial nephrectomy.

The preservation of renal function has become a central concern in the surgical management of renal tumors, especially given the long-term consequences of chronic kidney disease on patient morbidity and mortality. Partial nephrectomy is preferred for localized renal masses as it allows for oncologic control while maintaining renal function. Traditionally, renorrhaphy involves a two-layer closure including both medullary and cortical sutures. However, recent literature suggests that omitting the cortical suture may reduce renal parenchymal volume loss and warm ischemia time, while possibly introducing a higher rate of minor complications.

Despite growing interest in minimally invasive nephron-sparing techniques, robust prospective and randomized trials directly comparing single-layer (medullary-only) and double-layer (cortical and medullary) renorrhaphy remain scarce. The single-layer technique, first proposed to address concerns over unnecessary cortical compression and ischemic injury, is gaining attention for its simplicity and potential advantages in reducing blood loss and operative time.

This trial aims to evaluate whether avoiding cortical suturing during robot-assisted partial nephrectomy leads to improved postoperative renal function, reduced blood loss, and shorter surgical duration. Patients will be randomly assigned to undergo either medullary-only renorrhaphy or the conventional dual-layer approach. Both techniques will be assessed for their effect on warm ischemia time, complication rates, renal volume loss, and surgical efficiency.

The study will enroll 80 patients undergoing partial nephrectomy for renal masses, distributed evenly across the two intervention groups. This sample size was calculated to ensure statistical power to detect differences in estimated blood loss, the primary outcome. A broad range of secondary outcomes will be measured at multiple postoperative time points, including estimated glomerular filtration rate, renal volume, incidence of surgical complications, and quality of life indicators.

By employing a randomized, prospective, and blinded design, the trial seeks to minimize bias and deliver high-quality evidence to guide future surgical decision-making. Ultimately, the study aims to clarify whether cortical renorrhaphy can be safely omitted without compromising patient outcomes, potentially simplifying surgical technique and improving recovery profiles in this patient population.

Interventions

• Procedure Medullary-only suturing (single-layer)
  Only the base layer (medulla) is sutured after tumor excision, Cortical suturing is omitted. Hemostatic agents are applied.
• Device Suture
  Synthetic absorbable monofilament suture (Caproyl™ 3-0).
• Procedure Medullary and cortical suturing (two-layer)
  Both medullary and cortical layers are sutured after tumor excision, Performed with robotic assistance using absorbable sutures. Hemostatic agents are applied
• Device Suture
  Synthetic absorbable monofilament suture (Caproyl™ 3-0), absorbable braided suture (Vicryl™ 0)
• Device Hemostatic Agent
  Hemostatic agents (e.g., Bleed Stp Plus, Surgicel® Fibrillar, Hemopatch®).

Primary outcome measures

• Estimated Blood loss [Time frame: Perioperative/Periprocedural time]

Secondary outcome measures (7)

• Change in estimated glomerular filtration rate (eGFR) [Time frame: 1 day, 2 weeks, 2 months, and 5 months]
• Percentage renal volume loss [Time frame: 4 months]
• Warm ischemia time [Time frame: Perioperative/Periprocedural time]
• Participants with intraoperative or postoperative complications [Time frame: Through 5 months]
• Console time [Time frame: Perioperative/Periprocedural time]
• Length of hospital stay [Time frame: From the date of surgery until the date of hospital discharge, assessed up to 30 days postoperatively]
• Participants requiring intraoperative conversion [Time frame: Perioperative/Periprocedural time]

Eligibility criteria

Inclusion criteria

• Diagnosis of renal mass confirmed by computed tomography (CT) or magnetic resonance imaging (MRI)
• Indication for partial nephrectomy
• Written informed consent
• Expected survival of at least 6 months
• Eastern Cooperative Oncology Group (ECOG) score performance status ≤ 1
• Negative serum or urine pregnancy test within 24 hours before surgery for women of childbearing potential
• Recovery from any prior therapy-related toxicity to grade 1 or better
• If a biopsy has been performed, pathology consistent with renal cell carcinoma (RCC)

Exclusion criteria

• Solitary kidney
• Multiple or bilateral renal masses if more than one mass is operated on simultaneously or within less than 4 months
• Hepatic or renal toxicity grade ≥ 2 with glomerular filtration rate (GFR) < 30 according to Common Terminology Criteria for Adverse Events (CTCAE v4)
• Bleeding diathesis
• Inability to maintain anticoagulation for surgery
• Participation in another experimental trial simultaneously or within 30 days prior to enrollment
• Significant acute or chronic medical, neurological, or psychiatric condition that could compromise safety, limit study completion, or impair study objectives in the opinion of the Principal Investigator

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Brazil · 2 centers

• Hospital MaterDei Salvador — Salvador
• Brazilian Institute of Robotic Surgery — Salvador

Publications

• Williams RD, Snowden C, Frank R, Thiel DD. Has Sliding-Clip Renorrhaphy Eliminated the Need for Collecting System Repair During Robot-Assisted Partial Nephrectomy? J Endourol. 2017 Mar;31(3):289-294. doi: 10.1089/end.2016.0562. Epub 2017 Jan 16. PMID 27960537
• Arora S, Bronkema C, Porter JR, Mottrie A, Dasgupta P, Challacombe B, Rha KH, Ahlawat RK, Capitanio U, Yuvaraja TB, Rawal S, Moon DA, Sivaraman A, Maes KK, Porpiglia F, Gautam G, Turkeri L, Bhandari M, Jeong W, Menon M, Rogers CG, Abdollah F. Omission of Cortical Renorrhaphy During Robotic Partial Nephrectomy: A Vattikuti Collective Quality Initiative Database Analysis. Urology. 2020 Dec;146:125-1 PMID 32941944
• Alrishan Alzouebi I, Williams A, Thiagarjan NR, Kumar M. Omitting Cortical Renorrhaphy in Robot-Assisted Partial Nephrectomy: Is it Safe? A Single Center Large Case Series. J Endourol. 2020 Aug;34(8):840-846. doi: 10.1089/end.2020.0121. PMID 32316759
• Bahler CD, Dube HT, Flynn KJ, Garg S, Monn MF, Gutwein LG, Mellon MJ, Foster RS, Cheng L, Sandrasegaran MK, Sundaram CP. Feasibility of omitting cortical renorrhaphy during robot-assisted partial nephrectomy: a matched analysis. J Endourol. 2015 May;29(5):548-55. doi: 10.1089/end.2014.0763. Epub 2015 Mar 10. PMID 25616087
• Kazama A, Attawettayanon W, Munoz-Lopez C, Rathi N, Lewis K, Maina E, Campbell RA, Lone Z, Boumitri M, Kaouk J, Haber GP, Haywood S, Almassi N, Weight C, Li J, Campbell SC. Parenchymal volume preservation during partial nephrectomy: improved methodology to assess impact and predictive factors. BJU Int. 2024 Aug;134(2):219-228. doi: 10.1111/bju.16300. Epub 2024 Feb 14. PMID 38355293
• Hung AJ, Cai J, Simmons MN, Gill IS. "Trifecta" in partial nephrectomy. J Urol. 2013 Jan;189(1):36-42. doi: 10.1016/j.juro.2012.09.042. Epub 2012 Nov 16. PMID 23164381
• Ruiz Guerrero E, Claro AVO, Ledo Cepero MJ, Soto Delgado M, Alvarez-Ossorio Fernandez JL. Robotic versus Laparoscopic Partial Nephrectomy in the New Era: Systematic Review. Cancers (Basel). 2023 Mar 16;15(6):1793. doi: 10.3390/cancers15061793. PMID 36980679
• Young M, Jackson-Spence F, Beltran L, Day E, Suarez C, Bex A, Powles T, Szabados B. Renal cell carcinoma. Lancet. 2024 Aug 3;404(10451):476-491. doi: 10.1016/S0140-6736(24)00917-6. Epub 2024 Jul 18. PMID 39033764

Identifiers

NCT: NCT07190638 · 87015525.0.1001.5128

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗