Clinical trials for MALS and related compression syndromes

By the MALS Compass editorial teamPublished November 8, 2026Physician review: planned

Clinical trials tracker illustration. Illustration: our own diagram, not a patient scan.

This page lists every study registered on ClinicalTrials.gov for median arcuate ligament syndrome (MALS) and four related vascular compression syndromes. It is updated automatically every day from the official U.S. registry, so you can see which studies are open, which are planned and which have finished.

How to use this page

Open studies are listed first. "Recruiting" means the study team is looking for participants now; "Not yet recruiting" means it has been registered but has not started.
Each title links to the official record, which shows who can take part (eligibility), the study locations and the contact for the study team.
"New" marks studies that appeared in the registry in the last 30 days.
Talk to your own doctor before contacting a study team. Taking part in research is always voluntary.

Jump to: MALS · SMA syndrome · Nutcracker syndrome · May-Thurner syndrome · Pelvic congestion syndrome

Table of Contents

MALS (median arcuate ligament syndrome)

4 registered studies, 3 open or opening soon.

Study	Status	Type / phase	Where	Last update
Coeliac Artery Release or Sham Operation NCT05468580 · Medisch Spectrum Twente	Recruiting	Interventional	Netherlands	2026-03-16
Intestinal Ischemia Biomarker in Patients With Chronic Mesenteric Ischemia NCT06468774 · Oslo University Hospital	Recruiting	Observational	Norway	2025-07-30
Novel Feasibility Study Demonstrating the Utility of the Intuitive Da Vinci Single Port Robotic System for Treatment of Median Arcuate Ligament Release NCT07888764 · University of Alabama at Birmingham	Not yet recruiting	Observational	Not listed	2026-10-22
Investigation of Chronic Intestinal Ischemia NCT02914912 · Oslo University Hospital	Active, not recruiting	Observational	Norway	2026-04-23

SMA syndrome (Wilkie syndrome)

5 registered studies, 2 open or opening soon.

Study	Status	Type / phase	Where	Last update
GT Metabolic Magnet System in Adults With Gastrointestinal Disorders NCT07317076 · GT Metabolic Solutions, Inc.	Recruiting	Interventional	Canada	2026-05-19
Ultrasound Evaluation of Superior Mesenteric Artery Measurements in a Healthy Pediatric Population NCT04515251 · Ente Ospedaliero Cantonale, Bellinzona	Recruiting	Observational	Switzerland	2025-07-31
Comparison of One Anastomisis Gastric Bypass and Duodeno-Jejunostomy for Treating SMA Syndrome NCT06970093 · Ain Shams University	Completed	Interventional	Egypt	2025-12-08
Fluoxetine in Refractory Superior Mesenteric Artery Syndrome by Targeting Comorbid Somatic Symptom Disorder NCT07115472 · Xijing Hospital of Digestive Diseases	Completed	Interventional	China	2025-08-14
SMAS: a Prospective Study in a Single Institution NCT03416647 · Azienda Ospedaliera di Padova	Completed	Interventional	Italy	2018-01-31

Nutcracker syndrome

3 registered studies, 1 open or opening soon.

Study	Status	Type / phase	Where	Last update
Lumbar Vein Embolization for Chronic Headaches With Nutcracker Physiology NCT06077747 · Mayo Clinic	Recruiting	Interventional	United States	2025-11-18
Body Composition, Urine Protein, and Kidney Blood Flow After Nutritional Counseling in Children With Nutcracker Syndrome NCT07868406 · Kanuni Sultan Suleyman Training and Research Hospital	Completed	Observational	Turkey (Türkiye)	2026-10-09
Renal Autotransplantation; Case Series NCT05115812 · Methodist Health System	Status unknown	Observational	United States	2024-03-27

May-Thurner syndrome (iliac vein compression)

19 registered studies, 3 open or opening soon.

Study	Status	Type / phase	Where	Last update
Pelvic Vein Quantitative Flow Characterization Using 2D and 4D Flow MRI NCT06888024 · Ningcheng Peter Li	Recruiting	Interventional	United States	2026-09-24
Vascular Lab Resource (VLR) Biorepository NCT05628948 · The Cleveland Clinic	Recruiting	Observational	United States	2025-12-19
Anticoagulant Plus Antiplatelet Therapy Following Iliac Vein Stenting NCT04694248 · First Affiliated Hospital of Zhejiang University	Recruiting	Interventional	China	2025-09-25
Prevalence of May-Thurner Syndrome in 1st-degree Relatives of Symptomatic Patients NCT05409781 · University Hospital of Limerick	Withdrawn	Observational	Not listed	2025-09-18
The Use and Reproducibility of Duplex Ultrasound to Provide Indices of Left Common Iliac Vein Diameter NCT06180122 · Imperial College London	Completed	Interventional	United Kingdom	2025-09-03
Venous Stent for the Iliofemoral Vein Investigational Clinical Trial Using the DUO Venous Stent System NCT04580160 · Vesper Medical, Inc.	Completed	Interventional	United States, Poland	2025-05-15
The Efficacy and Safety of Interventions on the Pelvic Veins in Pelvic Venous Disorders NCT05076448 · Pirogov Russian National Research Medical University	Completed	Observational	Russia	2024-12-31
Rivaroxaban for the Prevention of Deep Vein Thrombosis in Patients With Left Iliac Vein Compression - The PLICTS Study NCT04067505 · Second Affiliated Hospital, Zhejiang University, School of Medicine	Status unknown	Interventional Phase 3	China	2024-04-18
Bern Venous Stent Registry NCT02433054 · University of Zurich	Completed	Observational	Switzerland	2023-10-12
BARD® The VENOVO™ Venous Stent Study for Treatment of Iliofemoral Occlusive Disease NCT02655887 · C. R. Bard	Completed	Interventional	United States, Australia, Germany, Ireland +3	2021-02-04
Treatment of the Postthrombotic Syndrome With the Oblique Stent - TOPOS Study NCT02942394 · Optimed Medizinische Instrumente GmbH	Completed	Observational	Austria, Germany, Netherlands, Switzerland	2021-01-12
Role of IVUS in Management of Iliocaval Obstruction NCT04024215 · Assiut University	Status unknown	Observational	Egypt	2020-05-11
Comparison of Intravascular Ultrasound With Venography in the Diagnosis and Treatment of Iliac Vein Compression Syndrome NCT03309969 · Shanghai Zhongshan Hospital	Status unknown	Observational	China	2017-10-16
Color Doppler U/S vs MSCT Venography in May-Thurner Syndrome NCT03262987 · Assiut University	Status unknown	Observational	Not listed	2017-08-28
Balloon Test for Iliac Vein Compression NCT02584374 · Maastricht University Medical Center	Status unknown	Observational	Netherlands	2016-01-22
Treadmill Pilot Study (Invasive Pressure Measurements in PTS) NCT01846780 · Maastricht University Medical Center	Completed	Observational	Netherlands	2015-10-21
Vascular Ultrasound Versus Intravascular Ultrasound for Diagnosing Iliac Vein Obstruction NCT02240914 · Fabio H Rossi	Status unknown	Observational	Brazil	2014-09-16
Iliac Vein Stenting in Advanced Chronic Venous Insufficiency NCT02149212 · Instituto Dante Pazzanese de Cardiologia	Completed	Interventional Phase 4	Brazil	2014-07-23
Multi-detector Computer Tomography Protocol Project: Chest Imaging Technique and Case Presentation NCT01206751 · Taipei Medical University WanFang Hospital	Completed	Observational	Taiwan	2010-09-22

Pelvic congestion syndrome

29 registered studies, 8 open or opening soon.

Study	Status	Type / phase	Where	Last update
Trial of Ovarian Vein and Pelvic Vein Embolization in Women With Chronic Pelvic Pain and Pelvic Varices NCT06168058 · Weill Medical College of Cornell University	Recruiting	Interventional	United States	2026-10-16
Endovascular Management of Pelvic Congestion Syndrome NCT07735156 · Sohag University	Recruiting	Interventional	Egypt	2026-07-29
HEMOVAR Study on Hemorrhoids and Varicose Veins NCT07317492 · Aydin Adnan Menderes University	Recruiting	Observational	Turkey (Türkiye)	2026-04-29
Quantify the Degree of Pain Relief of Pelvic Congestion Syndrome Following Gonadal Vein Embolization NCT03794466 · University of Kansas Medical Center	Recruiting	Observational	United States	2026-03-23
Glue Embolization vs Conservative Treatment for Pelvic Congestion Syndrome NCT06560294 · Tanta University	Recruiting	Interventional	Egypt	2025-08-19
Study of Venous Outflow From the Lower Limbs in Patients With Pelvic Varicosities NCT06124664 · Pirogov Russian National Research Medical University	Recruiting	Observational	Russia	2024-12-27
Embolization of Ovarian Vein and Pelvic Venous Reservoir for Treatment of Secondary Pelvic Congestion Syndrome NCT07472504 · Mark Magdy Zekry	Not yet recruiting	Interventional	Not listed	2026-03-16
Embolization Strategies for Pelvic Venous Disorders: Foam + Glue vs Foam + Coils NCT07221695 · Kafrelsheikh University	By invitation	Interventional	Egypt	2025-10-28
Effectiveness of Endovascular Plug Embolization in Pelvic Congestion Syndrome NCT06553014 · Halil Ibrahim Altun	Completed	Observational	Turkey (Türkiye)	2026-01-08
The Efficacy and Safety of Interventions on the Pelvic Veins in Pelvic Venous Disorders NCT05076448 · Pirogov Russian National Research Medical University	Completed	Observational	Russia	2024-12-31
Pelvic Congestion Syndrome Post Tubal Ligation Versus Salpingectomy Performed During Caesarean Section NCT06509425 · Ain Shams University	Status unknown	Interventional	Egypt	2024-07-19
Pain and Clinical Reflections in Pelvic Congestion Syndrome NCT06507267 · Kanuni Sultan Suleyman Training and Research Hospital	Status unknown	Observational	Turkey (Türkiye)	2024-07-18
Comparative Study Between Isolated Iliac Vein Stenting Versus Concomitant Iliac Vein Stenting With Pelvic Vein Embolization in Patients With Pelvic Venous Insufficiency Secondary to Nonthrombotic Iliac Vein Lesions NCT06311669 · Ain Shams University	Status unknown	Interventional	Egypt	2024-03-15
Neuropeptides and Venous Pelvic Pain NCT03921788 · Pirogov Russian National Research Medical University	Completed	Observational	Russia	2023-10-23
Effectiveness of Hormonal Intrauterine Device in Treating PCS Compared to Oral Progestin NCT05050357 · Assiut University	Completed	Interventional	Egypt	2023-07-21
Quality of Life Questionnaire and Disease Severity Scale NCT05889000 · Kazan State Medical University	Completed	Observational	Russia	2023-06-05
Study to Investigate the Influence of Compression Treatment in Patients With Pelvic Congestion Syndrome (PCS) NCT05553158 · The Whiteley Clinic	Status unknown	Interventional	United Kingdom	2022-09-23
Clinical Efficacy of Conservative Treatment in Female Patients With Plevic Congestion Syndrome NCT04512443 · Interregional Clinical Diagnostic Center, Russia	Completed	Observational	Russia	2020-08-13
Embolization of Pelvic Veins in Treatment of Pelvic Congestion Syndrome NCT03165214 · Assiut University	Withdrawn	Interventional	Egypt	2020-08-12
Assessment of Pain of Pelvic Congestion Syndrome Treated by Coils Embolization NCT04461860 · University Hospital, Brest	Status unknown	Observational	France	2020-07-08
Endovascular Versus Medical Treatment for the Pelvic Congestion Syndrome NCT04358497 · Hospital de Clínicas Dr. Manuel Quintela	Status unknown	Interventional Phase 4	Not listed	2020-04-24
Pelvic Varicose Veins Treated With Vascular Plugs Type Amplatzer: REPiVAC NCT04115137 · Group of Research in Minimally Invasive Techniques	Status unknown	Observational	Spain	2019-10-03
Pelvic Congestion Syndrome and Endometriosis NCT03568149 · IRCCS Azienda Ospedaliero-Universitaria di Bologna	Status unknown	Observational	Italy	2019-06-12
Duplex US in Pelvic Congestion Syndrome in Females (PCS) NCT03943381 · Assiut University	Status unknown	Observational	Not listed	2019-05-09
Embolization of Pelvic Varicosities in Patients With Pelvic Congestion Syndrome NCT03057067 · St. Olavs Hospital	Terminated	Interventional	Norway	2019-02-08
MRI & MRV in Pelvic Congestion Syndrome in Females NCT03252041 · Assiut University	Status unknown	Observational	Not listed	2017-08-17
Fibered Platinum Coils vs Vascular Plugs in Pelvic Varices Embolization for the Treatment of Pelvic Congestion Syndrome NCT02796092 · Group of Research in Minimally Invasive Techniques	Completed	Interventional	Spain	2017-03-29
Evaluation of PerformanCe of the Peripheral EOS in the Treatment of Varicocele or Pelvic Congestion SynDromE NCT02033863 · ArtVentive Medical Group, Inc.	Status unknown	Observational	Belgium, Poland, Switzerland	2015-06-24
Pelvic Embolisation to Reduce Recurrent Varicose Veins - Recurrent NCT01909024 · The Whiteley Clinic	Status unknown	Interventional	United Kingdom	2014-05-19

Source: ClinicalTrials.gov (U.S. National Library of Medicine), checked November 9, 2026. Status is shown as reported by the registry. A listing is not an endorsement and does not mean a study is right for you: read the official record and discuss it with your doctor.

Why so few studies?

These conditions are rare and hard to diagnose, and there is no agreement on diagnostic criteria for MALS, which makes it difficult to recruit enough patients for a trial. Most of what doctors know comes from case series of patients treated at single centers. Our page on the research gap shows how little research funding these conditions receive.

Questions to ask before joining a study

What is the study trying to find out, and what happens to me if I take part?
Could I be assigned to a placebo or sham procedure?
What are the possible risks, and who pays for study-related care and travel?
Can I leave the study at any time, and what happens to my care if I do?
How will the results be shared with participants?

Read about the conditions: MALS, SMA syndrome, nutcracker syndrome, May-Thurner syndrome and pelvic congestion syndrome.

MALS Compass is an independent educational website, not a medical provider, and is not affiliated with any hospital, clinic or university. This page is educational information and does not replace advice from your own doctor. For any question about your health, please contact your doctor or an official healthcare institution.