Orthogonal Polarization Spectral Imaging: A New Tool in Morphologic Surveillance in Intestinal Transplant Recipients N. Cautero, R. Gelmini, E. Villa, A. Bagni, A. Merighi, M. Masetti, F. Di Benedetto, F. Di Francesco, L. Bezer, B. Begliomini, E. Jovine, and A.D. Pinna I NTESTINAL TRANSPLANTATION (ITx) can be con- sidered a lifesaving procedure in patients with intestinal failure. However, despite improvements in the surgical technique and in patient selection, as well as in immuno- suppressive therapy, successful ITx requires an early diag- nosis of graft rejection. Acute cellular rejection (ACR) remains the most common and serious complication in clinical ITx. In this scenario frequent endoscopic and histologic surveillance are mandatory to achieve an early diagnosis of rejection and to tailor an effective immunosup- pressive regimen. We compared zoom video endoscope (ZVE) 1 and orthogonal polarization spectral (OPS) imag- ing as techniques to predict qualitative modifications of microscopic architecture and villi microcirculation for the diagnosis of acute cellular rejection in small bowel trans- plant patients. METHODS The Cytoscan (Cytometrics Inc. Philadelphia, Penna, USA) is a newly developed tool that works as an intravital polarized light microscope (IVM) 2 capable of delivering images of vascular beds of the explored tissue without transillumination and fluorescent dyes for contrast imaging. The OPS device consists of an easy to handle objective tube that, when covered with a sterile disposable lens, can be placed on organ or tissue surface. Green polarized light (550 nm) is used because it keeps the multiple scattering depth small and because it is maximally absorbed by the hemoglobin in the red blood cells (RBC). Connected to a CCD camera, OPS imaging provides remarkable images of cells flowing through the microcirculation. 3,4 From December 2000 until August 2001 we performed nine ITx transplants (Table 1): six isolated ITx, two modified multivisceral transplants (MMVTx), and one multivisceral transplant (MVTx). The immunosuppressive protocol consisted of tacrolimus, dacli- zumab, and steroids, and in some cases also rapamycin was added to the regimen, secondary to tacrolimus-related toxicity or rejec- tion. Rejection surveillance was accomplished by performing graft ileoscopies with ZVE (Pentax EC-3830 LZ, Tokyo, Japan) and intestinal biopsies through a surgically created distal ileostomy every 2 to 4 days for the first 2 weeks, then weekly for the following 2 months and monthly thereafter. During rejection episodes ileos- copy and biopsies were obtained every day until its resolution. In addiction of ZVE, the patients underwent frequent IVM evalua- tion through ileostomy to observe microvascular geometry at different times in the presence or not of ACR. Patients 1 and 2 underwent IVM analysis several days after ITx while the other were monitored starting from skin closure. RESULTS We compared OPS frames with ZVE images and histologic specimens processed for hematoxylin and eosin (H&E) From the Liver and Multivisceral Transplant Center (N.C., R.G., M.M., F.D.B., F.D.F., L.B., E.J., A.D.P.), Department of Gastro- enterology (E.V., A.M.) and Department of Pathology (A.B.), Division of Anesthesiology and Critical Care (B.B.), University of Modena and Reggio Emilia, Modena, Italy. Address reprint requests to Antonio Daniele Pinna, Liver and Multivisceral Transplant Center, University of Modena and Reg- gio Emilia, Azienda Ospedaliera-Policlinico di Modena, Via del Pozzo 71, 41100 Modena Italy. E-mail: pinna.antonio@unimo.it Table 1. Demographic Characteristic and Etiology of Intestinal Transplant Recipients at The University of Modena Transplant Center Patient Gender Age (y) Type of Graft Disease 1 GP M 36 Isolated small bowel Chronic intestinal pseudobstruction 2 CI F 21 Isolated small bowel Chronic intestinal pseudobstruction 3 PS F 28 MMV without liver Chronic intestinal pseudobstruction 4 AV M 53 MMV without liver Garder’s syndrome + desmoid tumors 5 MF F 37 Isolated small bowel Radiation enteritis 6 CAM F 55 Isolated small bowel Intestinal infarction 7 MP F 37 Isolated small bowel Chronic intestinal pseudobstruction 8 AG M 49 Isolated small bowel Intestinal angiomatosys 9 CR F 31 Multivisceral with liver Short bowel syndrome 0041-1345/02/$–see front matter © 2002 by Elsevier Science Inc. PII S0041-1345(02)02671-4 655 Avenue of the Americas, New York, NY 10010 922 Transplantation Proceedings, 34, 922–923 (2002)