Hepatobiliary scintigraphy after Kasai procedure for biliary atresia: clinical correlation and prognostic value.
OBJECTIVE
Kasai portoenterostomy (KP) is regarded as first-line treatment for biliary atresia, although its postoperative course is often unpredictable. Hepatobiliary scintigraphy using technetium-labeled iminodiacetic acid derivatives offers a dynamic, objective assessment both of parenchymal liver function and restored biliary excretion. The value of postoperative radionuclide scans was assessed prospectively in a large population of post-KP infants.


METHODS
Radionuclide scans consisted of an intravenous dose of 20 MBq of 99mTc mebrofenin iminodiacetic acid and subsequent gamma camera imaging. Four scan variables were evaluated: the hepatic extraction fraction (HEF; ie, initial liver uptake divided by the peak vascular uptake), the half-life of tracer excretion (TEX), the shape of the excretion curve, and the presence of activity in the Roux loop at 4 hours postinjection. All infants had type 3 biliary atresia with a median age at KP of 59 days (24-120 days). To assess predictive value, outcome (clearance of jaundice and need for transplant) was assessed at 6 months (for 1-week scan) and 2 years (for 6-month scan).


RESULTS
Eighty-seven infants underwent a radionuclide scan at 1 week post-KP. The median HEF was 34% (10%-90%). No relationship could be identified between HEF (P = .2) or excretion curve shape (P = .9) and outcome (at 6 months), and there were too few examples of a measurable TEX to allow meaningful comparison. The only predictive element at this time point was Roux loop activity (positive predictive value, 79%; negative predictive value, 53%; for "good" isotope bowel activity). Forty-four infants completed a second scan at 6 months. Median HEF increased from a baseline of 37% (11%-90%) to 64% (8%-100%) (P < .0001), although there was no significant intercorrelation (P = .12). The most predictive variables (of outcome at 2 years) were curve shape (positive predictive value, = 95%, negative predictive value, 82%) and TEX, and the least predictive was now Roux loop activity.


CONCLUSIONS
Early (at 7 days) hepatic scintigraphy is not predictive of poor outcome in general, although Roux loop activity does indicate later success. Later hepatic scintigraphy (at 6 months) allows a detailed assessment of dynamic liver function with biliary excretion variables predictive of outcome in the medium term.
Castagnetti
Marco
M
Department of Paediatric Surgery, King's College Hospital, SE5 9RS London, UK.
Davenport
Mark
M
Tizzard
Sarah
S
Hadzic
Nedim
N
Mieli-Vergani
Giorgina
G
Buxton-Thomas
Muriel
M
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000814:Aniline Compounds; D019072:Antibiotic Prophylaxis; D001219:Aspartate Aminotransferases / Q000097:blood; D001656:Biliary Atresia / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality / Q000601:surgery*; D001659:Biliary Tract / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001663:Bilirubin / Q000097:blood; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D005998:Glycine; D006207:Half-Life; D006801:Humans; D007098:Imino Acids / Q000493:pharmacokinetics; D007223:Infant; D007231:Infant, Newborn; D008099:Liver / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016031:Liver Transplantation; D008297:Male; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D011171:Portoenterostomy, Hepatic; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors; D016896:Treatment Outcome
D000305:Adrenal Cortex Hormones; D000814:Aniline Compounds; D007098:Imino Acids; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D001219:Aspartate Aminotransferases; C034837:technetium Tc 99m mebrofenin; D001663:Bilirubin; D005998:Glycine