Reflectance spectrometry for real-time hemoglobin determination of placental vessels during endoscopic laser surgery for twin-to-twin transfusion syndrome.

Abstract

OBJECTIVE:

The objective of the study was to develop a noninvasive technique to determine hemoglobin (Hb) content through spectral analysis of diffusely reflected broadband visible illumination from individual blood vessels during endoscopic fetal surgery for twin-to-twin transfusion syndrome (TTTS).

METHODS:

The reflection of an incoming xenon endoscopic light source was captured through a 630-mum-diameter optic fiber coupled to a fixed grating spectrometer (2-nm resolution). A 450- to 700-nm wavelength range was used for analysis. Three data-capturing methods were studied: (1) fixed-image spectrum capture with fiber aimed at (but not touching) center of a vessel, (2) no-touch scanning perpendicular to the vessel and dynamic spectral capture, and (3) dynamic spectral capture and analysis of the reflectance spectra during brief vessel touch.

RESULTS:

Eight controls (elective laparoscopic and thoracoscopic operations in children aged 1-17 years) were enrolled. Four vessels were analyzed in each case. The brief-touch technique with intensity peak analysis yielded the most reproducible results between multiple vessels in the same patient. Spectrometry was also applied to 2 TTTS patients. The (anemic) donor and (polycythemic) recipient twin fetuses could be differentiated with good correlation between vessels (arteries and vein) of the same fetus.

CONCLUSIONS:

It is possible to differentiate donor from recipient placental vessels by spectral analysis of the reflected light through the endoscope using a noninvasive and real-time method. This may improve the accuracy of endoscopic laser ablation of placental vessels in TTTS and may allow instant endoscopic Hb determination for laparoscopic procedures as well.

• Authors: Sean Curran, John W McMurdy, Stephen R Carr, Christopher S Muratore, Barbara M O'Brien, Gregory P Crawford, Francois I Luks
• Journal: Journal of pediatric surgery (J Pediatr Surg) Vol. 45 Issue 1 Pg. 59-64 (Jan 2010) ISSN: 1531-5037 [Electronic] United States
• PMID: 20105580 (Publication Type: Journal Article, Twin Study)
• Copyright: Copyright 2010 Elsevier Inc. All rights reserved.

Chemical References

• Hemoglobins

Topics

• Adolescent
• Child
• Child, Preschool
• Female
• Fetofetal Transfusion (blood, surgery)
• Fetoscopy (methods)
• Hemoglobinometry (methods)
• Hemoglobins (analysis)
• Humans
• Infant
• Laparoscopy
• Laser Coagulation (methods)
• Placenta (blood supply)
• Pregnancy
• Spectrophotometry (methods)
• Thoracoscopy