Justin Youp van Oostendorp

Mr. Justin Youp van Oostendorp

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Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 November 2022 in BMJ Open
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JOJustin Youp van Oostendorp
Justin Youp van Oostendorp
LDLisette Dekker
Lisette Dekker
SDSusan Van Dieren
Susan Van Dieren
WBWillem A Bemelman
Willem A Bemelman
IHIngrid J M Han-Geurts
Ingrid J M Han-Geurts
Introduction Perianal fistula is a burdening disease with an annual incidence of 6–12/100 000 in Western countries. More than 90% of crypto-glandular fistulas originate from perianal abscess. Despite adequate drainage, up to 83% recur or result in an anal fistula, the majority developing within 12 months. There is some evidence that gut-derived bacteria play a role in the development of perianal fistula. Up till now, it is not common practice to routinely administer prophylactic antibiotics to prevent anal fistula development. There is a need for a study to establish whether adding antibiotic treatment to surgical drainage of perianal abscess results in a reduction in perianal fistulas. Methods and analysis This multicentre, double-blind, randomised, placebo-controlled trial investigates whether addition of antibiotics (ciprofloxacin and metronidazole) to surgical drainage of a perianal abscess is beneficial compared with surgical drainage alone. The primary outcome is the development of a perianal fistula within 1 year. Secondary outcomes include quality of life, treatment costs, need for repeated drainage, patient-reported outcomes and other clinical outcomes. Participants are recruited in one academic and seven peripheral Dutch clinics. To demonstrate a reduction of perianal fistula from 30% to 15% when treated with adjuvant antibiotics with a two-sided alpha of 0.05, a power of 80% and taking a 10% loss to follow-up percentage into account, the total sample size will be 298 participants. Data will be analysed according to the intention-to-treat principle. Ethics and dissemination The study protocol has been approved by the Medical Ethics Review Committee of the Amsterdam University Medical Centers (nr. 2021_010). Written consent is obtained from each participant prior to randomisation into the study. The results of this trial will be submitted for publication in international peer-reviewed journals, presented at conferences and spread to coloproctological associations. Trial registration numbers 2020-004449-35; NCT05385887.

8 May 2024 in BJS Open
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JOJustin Youp van Oostendorp
Justin Youp van Oostendorp
CVCarolien Verkade
Carolien Verkade
IHIngrid J M Han-Geurts
Ingrid J M Han-Geurts
GMGrietje Vander Mijnsbrugge
Grietje Vander Mijnsbrugge
DWDareczka K Wasowicz-Kemps
Dareczka K Wasowicz-Kemps
DZDavid D E Zimmerman
David D E Zimmerman
The ligation of intersphincteric fistula tract is a surgical technique designed to treat trans-sphincteric anal fistulas aiming to preserve sphincter integrity. Recent studies suggest its efficacy in short-term fistula healing with limited impact on continence. However, comprehensive prospective data on long-term outcomes, including recurrence and bowel continence, are limited. The present study aims to report on the long-term functional outcomes. Patients who underwent the ligation of intersphincteric fistula tract procedure for trans-sphincteric cryptoglandular anal fistulas between July 2012 and October 2018 at two Dutch referral centres were retrospectively reviewed. The primary outcome of interest was the long-term bowel continence after the ligation of intersphincteric fistula tract procedure, using the faecal incontinence severity index. Short-term data (collected in 2018) and long-term data (collected in 2023) on bowel continence, healing rates and recurrences were obtained through electronic records and Rockwood questionnaires. Sankey diagrams were used to visually represent individual variations in continence status (preoperative versus follow-up). Among 110 patients included (50% female, median follow-up 92 months), 101 patients (92%) were treated with previous surgeries (median 2, range 0–6) and 80% had previous seton drainage. Preligation of intersphincteric fistula tract, 16% of the patients reported incontinence (mean(s.d.) faecal incontinence severity index: 2.4(7.5), increasing to 18% after ligation of intersphincteric fistula tract at short-term follow-up, including 11% newly induced cases. Long-term follow-up collected using Rockwood questionnaires (63% response rate) in 69 patients uncovered a 74% incontinency rate (mean(s.d.) faecal incontinence severity index: 9.22(9.5). In those patients without subsequent surgery 49% (17 of 35) reported incontinence at long-term follow-up. Primary fistula healing after ligation of intersphincteric fistula tract was 28%. Preoperative seton drainage significantly improved healing rates (33% versus 9%). Notably, 43% (34 of 79) of unhealed fistulas transitioned into intersphincteric tracts; in these patients, 19 were treated with subsequent fistulotomy achieving cure in 18 cases. Ligation of intersphincteric fistula tract healing rates fell below recent literature standards. Although the immediate impact on postoperative continence appears minimal, long-term incontinence rates are concerning. In recognizing the deterioration of individual continence, we advocate for a patient-centered approach and urge fellow researchers and clinicians to collect comprehensive prospective continence data.

14 February 2025 in Diseases of the Colon & Rectum
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JOJustin Youp van Oostendorp
Justin Youp van Oostendorp
LDLisette Dekker
Lisette Dekker
SDSusan Van Dieren
Susan Van Dieren
RVRuben Veldkamp
Ruben Veldkamp
WBWillem A. Bemelman
Willem A. Bemelman
OGOn behalf of the HollAND Study Group
On behalf of the HollAND Study Group
BACKGROUND: The optimal management strategy for grade III hemorrhoids remains a subject of ongoing debate. Hemorrhoidectomy is the criterion standard, but rubber band ligation offers a less invasive outpatient alternative. Treatment variability persists due to a lack of consensus on the preferred strategy. OBJECTIVE: To directly compare the effectiveness of rubber band ligation and hemorrhoidectomy in the treatment of grade III hemorrhoids. DESIGN: Open-label, parallel-group, randomized controlled noninferiority trial. SETTINGS: Multicenter study across 10 Dutch hospitals from October 2019 to September 2022. PATIENTS: Patients (aged 18 years or older) with symptomatic grade III (Goligher) hemorrhoids were included in this study. Exclusion criteria included prior rectal/anal surgery, more than 1 rubber band ligation/injection within the preceding 3 years, rectal radiation, preexisting sphincter injury, IBD, medical unfitness for surgery (ASA higher than 3), pregnancy, or hypercoagulability disorders. INTERVENTIONS: Randomized 1:1 to rubber band ligation or hemorrhoidectomy, with up to 2 banding sessions allowed. MAIN OUTCOME MEASURES: Primary outcomes included 12-month health-related quality of life and recurrence rate. Secondary outcomes included complications, pain, work resumption, and patient-reported outcome measures. RESULTS: Eighty-seven patients were randomly assigned (47 rubber band ligation vs 40 hemorrhoidectomy). Rubber band ligation was not noninferior to hemorrhoidectomy in quality-adjusted life years (–0.045; 95% CI, –0.087 to –0.004). Recurrence rate was worse in the rubber band ligation group (47.5% vs 6.1%), with an absolute risk difference of 41% (95% CI, 24%–59%). Complication rates were comparable. Pain scores after hemorrhoidectomy were higher during the first week (visual analogue scale 4 vs 1; p = 0.002). Rubber band ligation group returned to work sooner (1 vs 9 days; p = 0.021). Patient-reported hemorrhoidal symptom scores favored hemorrhoidectomy. LIMITATIONS: The primary limitation of the study was its early termination due to funding constraints, resulting in a relatively small sample size and limited statistical power. Patient recruitment was hindered by significant treatment preferences and the COVID-19 pandemic. CONCLUSIONS: Hemorrhoidectomy may benefit patients with grade III hemorrhoids in terms of quality of life, recurrence risk, and symptom burden, whereas rubber band ligation allows faster recovery with less pain. These findings can guide clinical decision-making. See Video Abstract. CLINICAL TRIAL REGISTRATION NUMBER: NCT04621695. COMPARACIÓN DE LA LIGADURA CON BANDA ELÁSTICA Y LA HEMORROIDECTOMÍA EN PACIENTES CON HEMORROIDES SINTOMÁTICAS GRADO III: ENSAYO MULTICÉNTRICO, ABIERTO, ALEATORIZADO, CONTROLADO Y DE NO INFERIORIDAD: ANTECEDENTES: La estrategia óptima de tratamiento para las hemorroides grado III sigue siendo un tema de debate continuo. La hemorroidectomía es el estándar de oro, pero la ligadura con banda elástica ofrece una alternativa ambulatoria menos invasiva. La variabilidad del tratamiento persiste debido a la falta de consenso sobre la estrategia preferida. OBJETIVO: Comparar directamente la eficacia de la ligadura con banda elástica y la hemorroidectomía en el tratamiento de las hemorroides grado III. DISEÑO: Ensayo de no inferioridad, controlado, aleatorizado, de grupos paralelos y abierto. ENTORNO CLINICO: Estudio multicéntrico en 10 hospitales holandeses desde octubre de 2019 hasta septiembre de 2022. PACIENTES: Pacientes (≥18 años) con hemorroides sintomáticas grado III (Goligher). Exclusiones: cirugía rectal/anal previa, >1 ligadura con banda elástica/inyección en los tres años anteriores, radiación rectal, lesión preexistente del esfínter, enfermedad inflamatoria intestinal, incapacidad médica para la cirugía (ASA >3), embarazo o trastornos de hipercoagulabilidad. INTERVENCIONES: Aleatorización 1:1 para ligadura con banda elástica o hemorroidectomía, con hasta dos sesiones de ligadura permitidas. PRINCIPALES MEDIDAS DE RESULTADOS: Primarias: calidad de vida relacionada con la salud a los 12 meses y tasa de recurrencia. Secundarias: complicaciones, dolor, reanudación del trabajo y medidas de resultados informadas por el paciente. RESULTADOS: Se aleatorizaron ochenta y siete pacientes (47 ligadura con banda elástica frente a 40 hemorroidectomía). La ligadura con banda elástica no fue no inferior a la hemorroidectomía en años de vida ajustados por calidad (-0,045, intervalo de confianza del 95 %: -0,087 a -0,004). La tasa de recurrencia fue peor en el grupo de ligadura con banda elástica (47,5 % frente a 6,1 %), con una diferencia de riesgo absoluto del 41 % (intervalo de confianza del 95 %: 24 %–59 %). Las tasas de complicaciones fueron comparables. Las puntuaciones de dolor posthemorroidectomía fueron más altas durante la primera semana (escala analógica visual 4 frente a 1; p = 0,002). El grupo de ligadura con banda elástica volvió al trabajo antes (1 frente a 9 días; p = 0,021). Las puntuaciones de síntomas hemorroidales notificadas por los pacientes favorecieron a la hemorroidectomía. LIMITACIONES: La principal limitación del estudio fue su finalización temprana debido a las limitaciones de financiación, lo que dio lugar a un tamaño de muestra relativamente pequeño y a un poder estadístico limitado. El reclutamiento de pacientes se vio obstaculizado por las preferencias significativas de tratamiento y la pandemia de COVID-19. CONCLUSIONES: La hemorroidectomía puede beneficiar a los pacientes con hemorroides de grado III en términos de calidad de vida, riesgo de recurrencia y carga de síntomas, mientras que la ligadura con banda elástica permite una recuperación más rápida con menos dolor. Estos hallazgos pueden orientar la toma de decisiones clínicas. (Traducción— Dr. Francisco M. Abarca-Rendon) NÚMERO DE REGISTRO DEL ENSAYO CLÍNICO: NCT04621695.

10 June 2025 in Techniques in Coloproctology
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JOJustin Youp van Oostendorp
Justin Youp van Oostendorp
Ugo GrossiUgo Grossi
Ugo Grossi
IHIlda Hoxhaj
Ilda Hoxhaj
MKM. L. Kimman
M. L. Kimman
SKSara Zwier Kuiper
Sara Zwier Kuiper
Gaetano GalloGaetano Gallo
Gaetano Gallo
Background: The diverse range of therapeutic options for hemorrhoidal disease (HD) highlights the need for precise classification systems to guide treatment. Although the Goligher classification remains the most widely used, it has been criticized for its simplicity and limited ability to capture symptom severity or guide treatment decisions. This study aims to evaluate the patient selection criteria and classification systems employed in randomized controlled trials (RCTs) for HD. Methods: A systematic review was conducted following the 2020 PRISMA guidelines. A comprehensive search of databases identified randomized controlled trials (RCTs) comparing treatments for HD, focusing on classification systems used for patient enrollment. Eligible studies included adult patients and at least one arm involving surgical treatment. Results: Out of 6692 records, 162 studies met the inclusion criteria, with a median cohort size of 84 patients and 55.4% male. Most studies (86.4%) used the Goligher system, though the majority did not fully describe or cite the system. Only 13.6% of studies employed more recent alternative classification systems. The most common outcome measures across studies were postoperative pain (147 studies) and complications (133 studies). Recurrence rates were reported in 42% of studies, yet 70% of these did not provide adequate inclusion criteria or references to Goligher’s classification. Conclusions: The inconsistent application of the Goligher classification and the variability in patient selection criteria across RCTs highlight the need for more nuanced and standardized systems. Future research should focus on refining classification methods and incorporating patient-reported outcomes to improve the reliability and relevance of HD trials. PROSPERO registration: CRD42023387339.

3 June 2023 in Trials
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JOJustin Youp van Oostendorp
Justin Youp van Oostendorp
TSTania Sluckin
Tania Sluckin
IHI. J. M. Han-Geurts
I. J. M. Han-Geurts
SDSusan Van Dieren
Susan Van Dieren
RSR. Schouten
R. Schouten
OGon behalf of the THROS trial research group
on behalf of the THROS trial research group
Introduction: Haemorrhoidal disease (HD) is a common condition with significant epidemiologic and economic implications. While it is possible to treat symptomatic grade 1–2 haemorrhoids with rubber band ligation (RBL) or sclerotherapy (SCL), the effectiveness of these treatments compatible with current standards has not yet been investigated with a randomised controlled trial. The hypothesis is that SCL is not inferior to RBL in terms of symptom reduction (patient-related outcome measures (PROMs)), patient experience, complications or recurrence rate. Methods and analysis: This protocol describes the methodology of a non-inferiority, multicentre, randomised controlled trial comparing rubber band ligation and sclerotherapy for symptomatic grade 1–2 haemorrhoids in adults (> 18 years). Patients are preferably randomised between the two treatment arms. However, patients with a strong preference for one of the treatments and refuse randomisation are eligible for the registration arm. Patients either receive 4 cc Aethoxysklerol 3% SCL or 3 × RBL. The primary outcome measures are symptom reduction by means of PROMs, recurrence and complication rates. Secondary outcome measures are patient experience, number of treatments and days of sick leave from work. Data are collected at 4 different time points. Discussion: The THROS trial is the first large multicentre randomised trial to study the difference in effectivity between RBL and SCL for the treatment of grade 1–2 HD. It will provide information as to which treatment method (RBL or SCL) is the most effective, gives fewer complications and is experienced by the patient as the best option. Ethics and dissemination: The study protocol has been approved by the Medical Ethics Review Committee of the Amsterdam University Medical Centers, location AMC (nr. 2020_053). The gathered data and results will be submitted for publication in peer-reviewed journals and spread to coloproctological associations and guidelines. Trial registration: Dutch Trial Register NL8377. Registered on 12–02-2020.

11 August 2023 in Diagnostics
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JOJustin Youp van Oostendorp
Justin Youp van Oostendorp
PHPieter van Hagen
Pieter van Hagen
GMGrietje Vander Mijnsbrugge
Grietje Vander Mijnsbrugge
IHIngrid J. M. Han-Geurts
Ingrid J. M. Han-Geurts
Anorectal manometry measurements exhibit significant interrater variability. Newer techniques like 3D high-resolution anorectal manometry (3D-HRAM) have the potential to enhance diagnostic accuracy and our understanding of defecation disorders. However, the extent of interrater variability in 3D-HRAM is still unknown. Between January 2020 to April 2022, patients referred for pelvic floor physical therapy (PFPT) due to functional defecation complaints underwent 3D-HRAM testing. In a retrospective analysis, three expert raters independently evaluated the 3D-HRAM results in a blinded matter to assess interrater agreement. The evaluation also determined the level of agreement concerning dyssynergic patterns during simulated defecation. The 3D-HRAM results of 50 patients (37 females) were included. Twenty-nine patients had complaints of fecal incontinence, eleven patients had chronic constipation, and ten patients had several other complaints. There was a substantial agreement (kappa 0.612) between the raters concerning the 3D images on dyssynergic patterns during simulated defecation. Our study emphasizes the need for standardized guidelines in evaluating 3D-HRAM test results to reduce subjectivity and further improve agreement among raters. Implementing these guidelines could improve diagnostic consistency and enhance personalized treatment strategies, increasing the reliability and usefulness of 3D-HRAM testing in clinical practice.