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RCC, Renal Cell CancerCORTEXNCT07190638

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

A study testing Medullary-only suturing (single-layer), Suture and Medullary and cortical suturing (two-layer) in people with RCC, Renal Cell Cancer, run by Brazilian Institute of Robotic Surgery at 2 sites in Brazil.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

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. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
RCC, Renal Cell Cancer
What is being tested?
Medullary-only suturing (single-layer), Suture and Medullary and cortical suturing (two-layer)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
80 participants
Where
2 sitesBrazil
Study dates
23 Jul 2025to 31 May 2027
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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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)

Who cannot join

  • 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

Trial locations and contacts

2 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Felipe P Albuquerque, MD. contact

+55 71 99733-3330

fpinhoalbuquerque@gmail.com

Brazil2 sites, 2 recruiting
  • Hospital MaterDei Salvador

    Salvador, Estado de Bahia, 40220-005

    Nilo J Leão, MD., +55 (71) 3401-7129 ext. 7129, nep@materdei.com.br

    Recruiting
  • Brazilian Institute of Robotic Surgery

    Salvador, Estado de Bahia, 43017030

    NILO J Leão, MD, +55 71 2626-3030, ibcrpesquisa@gmail.com

    Recruiting

Other trials in Brazil

About this study

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

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.

Read the 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.

Being tested
Medullary-only suturing (single-layer), Suture, Medullary and cortical suturing (two-layer), Hemostatic Agent
Keywords
Partial Nephrectomy, Robot-assisted, MEDULLARY SUTURE, MEDULLARY-ONLY SUTURE
Medical subject headings
Carcinoma, Renal Cell

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Medullary-only suturing (single-layer)Procedure or surgery

    Also called Single-layer renorrhaphy

    Only the base layer (medulla) is sutured after tumor excision, Cortical suturing is omitted. Hemostatic agents are applied.

  • SutureDevice

    Synthetic absorbable monofilament suture (Caproyl™ 3-0).

  • Medullary and cortical suturing (two-layer)Procedure or surgery

    Also called double-layer renorrhaphy

    Both medullary and cortical layers are sutured after tumor excision, Performed with robotic assistance using absorbable sutures. Hemostatic agents are applied

  • SutureDevice

    Synthetic absorbable monofilament suture (Caproyl™ 3-0), absorbable braided suture (Vicryl™ 0)

  • Hemostatic AgentDevice

    Hemostatic agents (e.g., Bleed Stp Plus, Surgicel® Fibrillar, Hemopatch®).

Study groups in NCT07190638
Study groupRoleWhat they receive
Medullary-only suturing (single-layer)ExperimentalAfter partial nephrectomy, only the medullary layer is sutured using a running 3-0 synthetic absorbable monofilament suture (Caproyl™). The cortical layer is not sutured. Hemostatic agents, such as Bleed Stp Plus, Surgicel® Fibrillar, or Hemopatch®, may be applied to support hemostasis.
Receives: Procedure: Medullary-only suturing (single-layer); Device: Suture; Device: Hemostatic Agent
Medullary and cortical suturing (two-layer)Active comparatorAfter partial nephrectomy, both the medullary and cortical layers are sutured. The medullary layer is closed with a running 3-0 Caproyl™ suture before unclamping. Then, the cortical layer is sutured with 0 Vicryl™ using a running technique. Hemostatic agents, such as Bleed Stp Plus, Surgicel® Fibrillar, or Hemopatch®, may be applied to assist in bleeding control.
Receives: Procedure: Medullary and cortical suturing (two-layer); Device: Suture; Device: Hemostatic Agent

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Estimated Blood loss

    Estimated blood loss, assessed to compare renorrhaphy techniques (single medullary suture vs. combined medullary and cortical suture) during partial nephrectomy. The volume, recorded in milliliters, was measured using a graduated collection canister connected to the assistant surgeon's suction device, with correction for the amount of saline solution instilled into the cavity.

    Measured: Perioperative/Periprocedural time

Secondary outcomes (7)
  1. Change in estimated glomerular filtration rate (eGFR)

    Difference in eGFR values calculated using the CKD-EPI formula between baseline (preoperative) and postoperative time points

    Measured: 1 day, 2 weeks, 2 months, and 5 months

  2. Percentage renal volume loss

    Percentage reduction in renal parenchymal volume calculated from CT scan measurements at 4 months compared with baseline preoperative volume.

    Measured: 4 months

  3. Warm ischemia time

    Duration, in minutes, of arterial clamping recorded during partial nephrectomy

    Measured: Perioperative/Periprocedural time

  4. Participants with intraoperative or postoperative complications

    Number of participants experiencing complications such as hematuria, pseudoaneurysm, or urinary fistula, graded according to the Clavien-Dindo classification.

    Measured: Through 5 months

  5. Console time

    Time in minutes from docking to undocking of the robotic system.

    Measured: Perioperative/Periprocedural time

  6. Length of hospital stay

    Number of days from the date of surgery until the date of hospital discharge.

    Measured: From the date of surgery until the date of hospital discharge, assessed up to 30 days postoperatively

  7. Participants requiring intraoperative conversion

    Number of participants converted to open or radical nephrectomy during the procedure.

    Measured: Perioperative/Periprocedural time

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Sep 2025
  2. Study start23 Jul 2025
  3. Primary completion31 Mar 2027 (estimated)
  4. Study completion31 May 2027 (estimated)

Resources

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 first group will undergo medullary-only suturing (single-layer) using 3-0 diameter synthetic absorbable monofilament poliglecaprone 25 suture (Caprofyl™), with early unclamping performed robotically. In the second group, both medullary and cortical suturing (two-layer) will be performed, using 3-0 Caprofyl™ for the medullary suture and, after early unclamping, 0-diameter braided synthetic absorbable polyglycolic suture (Vicryl™) for the cortical layer, also robotically assisted. If the surgeon deems it necessary to perform a second suture using Vicryl™ 0 in the first group after unclamping, it will be carried out, and the surgeon's reasoning will be documented. These patients will be analyzed separately in order to identify predictive factors for such a change. Hemostatic agents will be used in all groups.
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
80 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07190638
Sponsor's protocol ID
87015525.0.1001.5128
Acronym
CORTEX
Status last verified
Sep 2025
First submitted
25 Jul 2025
Last updated
24 Sep 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: The individual participant data (IPD) will not be shared in order to protect patient confidentiality and privacy. As the data may contain sensitive personal health information, maintaining strict confidentiality is essential and aligns with ethical and legal standards.

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.

    PubMed 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;146:125-132. doi: 10.1016/j.urology.2020.09.003. Epub 2020 Sep 15.

    PubMed 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.

    PubMed 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.

    PubMed 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.

    PubMed 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.

    PubMed 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.

    PubMed 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.

    PubMed 39033764
  • Shatagopam K, Bahler CD, Sundaram CP. Renorrhaphy techniques and effect on renal function with robotic partial nephrectomy. World J Urol. 2020 May;38(5):1109-1112. doi: 10.1007/s00345-019-03033-w. Epub 2019 Dec 2.

    PubMed 31792576
  • Rose TL, Kim WY. Renal Cell Carcinoma: A Review. JAMA. 2024 Sep 24;332(12):1001-1010. doi: 10.1001/jama.2024.12848.

    PubMed 39196544
  • Makino T, Kadomoto S, Izumi K, Mizokami A. Epidemiology and Prevention of Renal Cell Carcinoma. Cancers (Basel). 2022 Aug 22;14(16):4059. doi: 10.3390/cancers14164059.

    PubMed 36011051
  • Bray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomataram I, Jemal A. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024 May-Jun;74(3):229-263. doi: 10.3322/caac.21834. Epub 2024 Apr 4.

    PubMed 38572751

Questions about this trial

What is this clinical trial studying?

A study testing Medullary-only suturing (single-layer), Suture and Medullary and cortical suturing (two-layer) in people with RCC, Renal Cell Cancer, run by Brazilian Institute of Robotic Surgery at 2 sites in Brazil.

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 8 inclusion and 7 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 24 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 2 sites in Brazil. 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 Nilo J Leão, MD. (+55 71 2626-3030, ibcrpesquisa@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Estimated Blood loss (time frame: Perioperative/Periprocedural time). 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 NCT07190638, which also lists 12 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 24 Sep 2025.

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