Multilevel Analysis of the Neovascularization and Integration Process of a Nonvascularized Rectus Fascia Transplantation

Ewout Muylle; Arne Maes; Gert De Hertogh; Nele Van De Winkel; Greet Kerckhofs; Antoine Dubois; Vincent Vandecaveye; Lieven Thorrez; Ina Hennion; Marie-Paule Emonds; Steven Pans; Nathalie P Deferm; Diethard Monbaliu; Emilio Canovai; Tim Vanuytsel; Jacques Pirenne; Laurens J Ceulemans

doi:10.1097/TXD.0000000000001624

Multilevel Analysis of the Neovascularization and Integration Process of a Nonvascularized Rectus Fascia Transplantation

Transplant Direct. 2024 May 15;10(6):e1624. doi: 10.1097/TXD.0000000000001624. eCollection 2024 Jun.

Authors

Ewout Muylle^{1

2

3}, Arne Maes^{4

5

6}, Gert De Hertogh^{1

7

8}, Nele Van De Winkel^{1

9

10}, Greet Kerckhofs^{4

5

6

11}, Antoine Dubois^{1

2

12}, Vincent Vandecaveye^{13

14}, Lieven Thorrez¹⁵, Ina Hennion¹⁵, Marie-Paule Emonds¹⁶, Steven Pans¹⁷, Nathalie P Deferm¹⁷, Diethard Monbaliu^{1

2

12}, Emilio Canovai¹⁸, Tim Vanuytsel^{1

19

20}, Jacques Pirenne^{1

2

12}, Laurens J Ceulemans^{1

3

21}

Affiliations

¹ Leuven Intestinal Failure and Transplantation (LIFT) Center, University Hospitals Leuven, Leuven, Belgium.
² Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium.
³ Department of Chronic Diseases and Metabolism, Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven, Leuven, Belgium.
⁴ Department of Materials Engineering, KU Leuven, Leuven, Belgium.
⁵ Biomechanics Lab, Institute of Mechanics, Materials and Civil Engineering, UCLouvain, Louvain-la-Neuve, Belgium.
⁶ Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium.
⁷ Department of Pathology, University Hospitals Leuven, Leuven, Belgium.
⁸ Unit of Translational Cell- and Tissue Research, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
⁹ Department of Abdominal Surgery, University Hospitals Leuven, Leuven, Belgium.
¹⁰ Department of Development and Regeneration, Unit of Urogenital, Abdominal and Plastic Surgery, KU Leuven, Leuven, Belgium.
¹¹ Prometheus Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium.
¹² Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.
¹³ Department of Radiology, University Hospitals Leuven, Leuven, Belgium.
¹⁴ Translational MRI Unit, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
¹⁵ Tissue Engineering Lab, Department of Development and Regeneration, KU Leuven, KULAK campus Kortrijk, Kortrijk, Belgium.
¹⁶ Histocompatibility and Immunogenetics Laboratory, Belgian Red Cross-Flanders, Mechelen, Belgium.
¹⁷ Department of Abdominal Surgery, Sint-Franciscusziekenhuis, Heusden-Zolder, Belgium.
¹⁸ Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
¹⁹ Department of Gastroenterology and Hepatology, University Hospitals Leuven, Leuven, Belgium.
²⁰ Department of Chronic Diseases and Metabolism, Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium.
²¹ Department of Thoracic Surgery, University Hospitals Leuven, Leuven, Belgium.

Abstract

Background: Failure to close the abdominal wall after intestinal transplantation (ITx) or multivisceral Tx remains a surgical challenge. An attractive method is the use of nonvascularized rectus fascia (NVRF) in which both layers of the donor abdominal rectus fascia are used as an inlay patch without vascular anastomosis. How this graft integrates over time remains unknown. The study aims to provide a multilevel analysis of the neovascularization and integration process of the NVRF.

Methods: Three NVRF-Tx were performed after ITx. Clinical, radiological, histological, and immunological data were analyzed to get insights into the neovascularization and integration process of the NVRF. Moreover, cryogenic contrast-enhanced microfocus computed tomography (microCT) analysis was used for detailed reconstruction of the vasculature in and around the NVRF (3-dimensional histology).

Results: Two men (31- and 51-y-old) and 1 woman (49-y-old) underwent 2 multivisceral Tx and 1 combined liver-ITx, respectively. A CT scan showed contrast enhancement around the fascia graft at 5 days post-Tx. At 6 weeks, newly formed blood vessels were visualized around the graft with Doppler ultrasound. Biopsies at 2 weeks post-Tx revealed inflammation around the NVRF and early fibrosis. At 6 months, classical 2-dimensional histological analysis of a biopsy confirmed integration of the fascia graft with strong fibrotic reaction without signs of rejection. A cryogenic contrast-enhanced microCT scan of the same biopsy revealed the presence of microvasculature, enveloping and penetrating the donor fascia.

Conclusions: We showed clinical, histological, and microCT evidence of the neovascularization and integration process of the NVRF after Tx.