Optimizing Operational Parameters for Diagnostic Vitrectomy

Официальное название

Optimizing Operational Parameters to Preserve Cellular Integrity During Diagnostic Vitrectomy: An Ex-Vivo Pilot Study With Blinded Outcome Assessment

Обзор

Single-center ex-vivo study using blood samples from healthy donors processed through a 25-gauge vitrectomy system. The study compares four combinations of operational parameters (vacuum pressure and cut rate) to evaluate their impact on cellular recovery and morphological preservation. Pre- and post-procedure complete blood counts and cytology smears will be analyzed to identify the settings that minimize cell loss and mechanical damage, with the ultimate goal of optimizing diagnostic yield in vitreoretinal lymphoma (VRL) vitrectomy.

Подробное описание

Primary vitreoretinal lymphoma (VRL) is a rare but aggressive intraocular malignancy, typically classified as a subtype of primary central nervous system lymphoma. It predominantly involves the retina and vitreous and is frequently associated with central nervous system disease. Clinical presentation often mimics chronic uveitis, leading to diagnostic delays and suboptimal management.

Definitive diagnosis of VRL requires cytopathologic confirmation through diagnostic vitrectomy, which provides vitreous samples for cytology, immunohistochemistry, flow cytometry, and molecular analyses (e.g., MYD88 mutation testing, IL-10/IL-6 ratio). However, despite the central role of vitreous biopsy, its diagnostic sensitivity remains limited to approximately 70% (Iuliano L et al. Int Ophthalmol 43, 2841-2849 (2023)), primarily due to the mechanical fragility and scarcity of malignant lymphoid cells.

During vitrectomy, the vitreous is fragmented and aspirated through a high-speed cutting probe (vitrector), which applies both mechanical cutting and vacuum forces. These operational parameters, while optimized for surgical efficiency and visualization, may inadvertently damage cells by rupturing membranes or disrupting nuclei, thereby reducing the yield and integrity of cellular material available for analysis.

Given the critical importance of maximizing diagnostic sensitivity in a disease with high morbidity and mortality, refining vitrectomy parameters to minimize cellular damage could represent a major advancement in the diagnostic workflow of VRL.

The present study aims to systematically evaluate the effect of different combinations of vacuum pressure and cut rate on cellular recovery and morphological preservation in a controlled ex-vivo vitreous model. Approximately 100 healthy donors will be enrolled and stratified into four experimental groups, each undergoing simulated diagnostic vitrectomy procedures under distinct parameter settings:

* Group A: Low vacuum / Low cut rate * Group B: Low vacuum / High cut rate * Group C: High vacuum / Low cut rate * Group D: High vacuum / High cut rate This design enables direct comparison of operational conditions to identify settings that optimize cell preservation and recovery. The ultimate goal is to inform best-practice recommendations for diagnostic vitrectomy in suspected VRL, potentially improving cytologic yield and overall diagnostic accuracy.

Вмешательства

• Другое Simulated vitrectomy
  The simulated vitrectomy is performed using the cutter handpiece, a microcannulated probe that combines a pneumatic cutting mechanism and a controlled aspiration system. The probe is directly inserted into the collection tube (ex-vivo model), allowing mechanical fragmentation and aspiration of donor suspended cells under the selected physical parameters (vacuum and cut rate, according to protocol).

Первичные конечные точки

• Difference in absolute lymphocyte count between post-processing and baseline measurements (Δ lymphocyte count). [Срок оценки: Same-day assessment, immediately after processing]

Вторичные конечные точки (2)

• Δ values for the listed CBC parameters [Срок оценки: Same-day assessment, immediately after processing]
• Semiquantitative cytology integrity score (smear evaluation) [Срок оценки: Same-day assessment, immediately after processing]

Критерии участия

Критерии включения

• Provision of written informed consent authorizing the anonymized research use of residual blood samples.
• Age 18-65 years at the time of donation.
• Eligibility for routine whole blood donation, according to the institutional and national standards of the Blood Transfusion Center.
• Good general health, as per standard donor screening procedures.

Критерии исключения

No additional exclusion criteria are defined beyond standard blood donation regulations. Exclusion from the study will therefore coincide with ineligibility for blood donation according to institutional protocols (e.g., due to infection, hematologic disease, recent surgery, or medication use that affects blood composition).

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Модель наблюдения

Другое

Центры проведения

Список центров уточняется — проверьте первичный протокол.

Публикации

• Menean M, Cicinelli MV, Rivolta MC, Marchese A, Modorati G, Bandello F, Miserocchi E. The Silent Masquerade: Clinical and Imaging Features of Asymptomatic Vitreoretinal Lymphoma. Am J Ophthalmol. 2024 Nov;267:153-159. doi: 10.1016/j.ajo.2024.07.004. Epub 2024 Jul 6. PMID 38977150
• Iuliano L, Marchese A, Miserocchi E, Corbelli E, Bongiovanni L, Ponzoni M, Bandello F, Codenotti M. Subretinal lavage during diagnostic vitrectomy: an adjunctive technique for cell sampling in suspected vitreoretinal lymphoma. Retin Cases Brief Rep. 2025 Apr 23. doi: 10.1097/ICB.0000000000001766. Online ahead of print. PMID 40279539
• Quintyn JC, Olle P, Courtade-Saidi M, Laurent C, Oberic L, Quintyn-Ranty ML. Cytological diagnosis of vitreoretinal lymphomas: A case series. Cytopathology. 2019 Jul;30(4):385-392. doi: 10.1111/cyt.12711. Epub 2019 May 23. PMID 31033057
• Iuliano L, Kacerik M, Corbelli E, Miserocchi E, Modorati G, Bandello F, Codenotti M. Panuveitis of undetermined origin after diagnostic pars plana vitrectomy: clinical characterization and long-term outcome from a tertiary referral center. Int Ophthalmol. 2023 Aug;43(8):2841-2849. doi: 10.1007/s10792-023-02683-5. Epub 2023 Mar 13. PMID 36913167
• Hwang CS, Yeh S, Bergstrom CS. Diagnostic vitrectomy for primary intraocular lymphoma: when, why, how? Int Ophthalmol Clin. 2014 Spring;54(2):155-71. doi: 10.1097/IIO.0000000000000022. PMID 24613891

Идентификаторы

NCT: NCT07408466 · CELLVIT

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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