Methods:
This study is a single-center, prospective case series of 20 patients who underwent surgical aortic valve replacement (SAVR) between January 2020 - July 2020 at the University of Rochester Medical Center (URMC). International Review Board (IRB) approval was obtained prior to commencing data collection. A waiver of informed consent was approved by the reviewing IRB. All patients who underwent elective surgical aortic valve replacement for severe aortic stenosis (mean gradient > 40 mmHg, AVA < 1 cm2, Vmax > 4 m/s) using the below technique were included. Pediatric patients (<18 years old) and those with mixed aortic valve pathology were excluded from this study.
The technique used for capturing debris developed during aortic valve leaflet removal and annulus debridement in SAVR for each of the 20 patients in our prospective case series is described below (Figure 1). Following the establishment of cardiopulmonary bypass, diastolic arrest of the heart and aortotomy, a surgical sponge is inserted into the left ventricle through the aortic valve. The aortic valve leaflets are then carefully excised, and the aortic annulus is meticulously debrided in the usual fashion. The left ventricle is then copiously irrigated with normal saline which is suctioned from the left ventricular cavity. The surgical sponge is then removed from the heart and sent to Surgical Pathology for gross, radiographic, and histologic analysis (as below). It is important to note that closed loop communication is used between the surgeon and operating room staff to confirm both the placement and removal of the surgical sponge during the procedure. The remainder of the procedure then proceeds in the usual fashion.
In the surgical pathology lab, the surgical sponges were grossly examined for any signs of debris, and then were radiographically imaged using a Kubtec XPERT radiography system. Unused sponges were also imaged as negative controls. Samples were then vigorously washed with isotonic saline in order to liberate debris and were then processed into cell blocks using standard protocols. The tissue blocks were stained with Hematoxylin and Eosin and von Kassa Calcium Stain (Figure 2). The resulting slides were then reviewed by two different Pathologists and scored quantitatively as positive or negative for the presence of acellular and cellular tissue and calcified debris. Positive controls for von Kassa were analyzed and deemed to be adequate. Quantitative information and photography were generated with Olympus BX45 microscopes using CellSens imaging software.