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.