OBJECTIVESAortic valve repair procedures are technically challenging, and current intraoperative evaluation methods often fail to predict the final echocardiographic result. We have developed a... Show moreOBJECTIVESAortic valve repair procedures are technically challenging, and current intraoperative evaluation methods often fail to predict the final echocardiographic result. We have developed a novel intraoperative aortic valve visualization and pressurization (AVP) device, enabling valve inspection under physiological conditions, and measuring aortic valve insufficiency (AI) during cardioplegic arrest.METHODSThe AVP device is attached to the (neo)aorta, after any type of aortic valve repair, while the heart is arrested. The root is pressurized (60–80 mmHg) using a saline solution and an endoscope is introduced. The valve is inspected, and the amount of valvular leakage is measured. Postoperative ‘gold standard’ transesophageal echocardiogram measurements of AI are performed and compared against regurgitation volume measured.RESULTSIn 24 patients undergoing valve-sparing root replacement, the AVP device was used. In 22 patients, postoperative echocardiographic AI was ≤ grade 1. The median leakage was 90 ml/min, IQR 60–120 ml/min. In 3 patients, additional adjustments after visual inspection was performed. In 2 patients, with complex anatomy, the valve was replaced. In one, after evaluation with the device, there was undesirable result visually and residual AI of 330 ml/min, and in another, 260 ml/min residual AI was measured and valve restriction on visual inspection.CONCLUSIONSThe novel AVP device enables intraoperative evaluation of the valve under physiological conditions, while still on arrested heart, and allows for targeted adjustments. The AVP device can be an important aid for intraoperative evaluation of the aortic valve, during valve repair and valve-sparing procedures, thereby making the operative result more predictable and the operation more efficient. Show less
Intraoperative imaging using near-infrared (NIR) fluorescence is a fast developing imaging modality as it provides real-time visual information during surgery (Chapter 1). The ability to detect... Show moreIntraoperative imaging using near-infrared (NIR) fluorescence is a fast developing imaging modality as it provides real-time visual information during surgery (Chapter 1). The ability to detect lymph nodes and tumours that need to be resected can assist the surgeon to improve surgery by reducing time of the procedure, reducing iatrogenic damage, and improve the number of radical resections. This thesis focuses on the introduction of NIR fluorescence imaging into the clinic. Part 1 of this thesis describes the optimization of NIR fluorescence imaging for sentinel lymph node (SLN) biopsy using the clinically available NIR tracer Indocyanine green (ICG) in various cancer types. Moreover, these studies show both the limitations as the clinical benefit of NIR fluorescence for SLN biopsy. Part 2 describes the use of NIR light for tumour detection. Tissue absorption and scattering in the NIR light spectrum was used for neoadjunvant treatment response monitoring in breast cancer patients. Moreover, NIR fluorescence imaging using NIR contrast agents was used for the intraoperative detection of otherwise difficult to localize liver metastases of colorectal cancer. Show less
