Klinički značaj načina određivanja torakalnih indeksa u dijagnostici i terapijskom tretmanu pektus ekskavatuma kod dece

Abstract

Cilj: Proveriti da li je moguće promeniti način CT verifikacije Hallerovog indeksa u okviru preoperativne pripreme pacijenata sa deformitetom grudnog koša po tipu pectus excavatum-a, uz utvrđivanje fiziološkog opsega vrednosti indeksa, njegove zavisnosti od uzrasta i pola, kao i respiratorne faze u kojoj se CT pregled izvodi. Utvrditi značaj vrednosti indeksa korekcije, indeksa asimetrije i indeksa torzije sternuma. Proveriti i mogućnost smanjivanja efektivne doze jonizujućeg zračenja kod primene CT tehnike jednog skena (single slice). Materijal i metod rada: Ispitivanje se sastojalo iz prospektivne studije koja je obuhvatila 30 pacijenata sa pektus ekskavatumom uz CT snimanje (single slice) u respiratornim fazama: ekspirijum i inspirijum. Na dobijenim snimcima su izračunati pored Halerovog indeksa i indeksi asimetrije, korekcije i sternalne torzije. Prema dobijenim rezultatima merenja i izračunavanja, donošena je odluka o načinu terapijskog tretmana. U retrospektivnoj studiji, urađena je analiza 100 CT pregleda grudnog koša kod dece gde nije verifikovan pectus excavatum, uz kalibriranje vrednosti indeksa u odnosu na uzrast i pol pacijenata. Retrospektivno istraživanje je obuhvatilo i analizu dodatnih 30 CT pregleda grudnog koša pacijenata sa deformitetom grudnog koša po tipu pectus excavatum-a, koji su dijagnostikovani i/ili operisani. Kod svih operisanih pacijenata je primenjenja Nusova operativna tehnika. U ovoj grupi pacijenata je izračunata srednja vrednost efektivne doze jonizujućeg zračenja, a dobijene vrednosti su potom komparirane sa efektivnim dozama koje su dobijene niskodoznim CT pregledima grudnog koša uz primenu novog protokola ("single-slice" tehnika u respiratornim fazama inspirijuma i ekspirijuma). Rezultati: Fiziološki opseg vrednosti Haller-ovog indeksa u populaciji zdravih pacijenata se kretao od 1,47 do 3,17 i u proseku je iznosio 2,23±0,32 (znatna pozitivna korelacija uzrasta i vrednosti HI). Na osnovu rezultata Man-Vitnijevog testa nije postojala polna razlika u posmatranoj grupi. Haller-ov indeks u grupi dijagnostikovane/operisane dece je u proseku iznosio 3,39 i kretao se u intervalu od 2,23 do 5,72 (korelacija između uzrasta ovih pacijenata i Haller-ovog indeksa je bila neznatna i negativna). Utvrđena je zavisnost veličine Haller-ovog indeksa od respiratorne faze u kojoj se CT pregled izvodi. Tako su prosečne vrednosti Haller-ovog indeksa u inspirijumu dece sa dijagnostikovanim deformitetom iznosile 2,69±0,76. Kod dece ove grupe u ekspirijumu vrednosti Haller-ovog indeksa su iznosile 3,49±1,19. U inspirijumu su samo 3/32 (9%) ispitanika imali vrednost HI preko 3,25 (granična vrednost za operativni tretman), dok ih je u ekspirijumu bilo znatno više 13/32 (41%), što je statistički značajna razlika (χ2=6,250; df =1; p=0,012). "Single-slice" tehnika CT pregleda u inspirijumu i ekspirijumu 20-25 puta smanjuje efektivnu dozu jonizujućeg zračenja. Zaključak: Vrednost Haller-ovog indeksa raste sa uzrastom deteta, dok nije utvrđena zavisnost Haller-ovog indeksa od pola. Moguće je promeniti načini CT verifikacije Haller-ovog indeksa u preoperativnoj pripremi za Nuss-ovu operaciju primenom "single-slice" tehnike u ekspiratornoj fazi. Osim Hallerovog indeksa, korisno je određivati i indeks korekcije, indeks asimetrije i indeks sternalne rotacije. Predlaže se protokol standardne preoperativne pripreme i lečenja pacijenata dečjeg uzrasta sa deformitetom grudnog koša po tipu pektus ekskavatuma, sa ciljem njegove primene u svakodnevnom radu u institucijama koje se bave ovim problemom, a u cilju poboljšanja kvaliteta dijagnostikovanja i krajnjeg ishoda lečenja.

Aim: The aim of this study was to verify whether it is possible to change the way of CT verification of Haller index (HI), as part of preoperative preparation for patients with pectus excavatum, with the determination of the physiological range of the index value, its dependence on the age and sex, as well as the respiratory phase during which the scan is performed. Also, the aim was to determine the significance of correction, asymmetry and sternal torsion indices values. Evaluate the possibility of reduction the effective dose of ionizing radiation using a single slice CT scan technique. Materials and methods: The study consisted of prospective study that included evaluation of CT scans (single slice technique) of 30 patients with pectus excavatum in both respiratory phases: expirium and inspirium. Haller index and indices of asymmetry, correction and sternal torsion were measured. The decision for the treatment was made according to the results of measurements and calculations of these indices. In retrospective study, 100 CT scans of the chest in children without the deformity (pectus excavatum) were analyzed, and the index value was calibrated depending on the age and gender. The retrospective study also included the analysis of another 30 CT scans in patients who were operated or diagnosed with pectus excavatum. Nuss procedure was used in all operated patients. In this group of patients the median value of effective dose of ionizing radiation was calculated, and the values were compared with the effective dose obtained using low-dose CT examinations applied in the new protocol (single-slice technique in inspiratory and expiratory respiratory phases). Results: The physiological range of Haller index value in healthy patients was from 1.47 to 3.17 and average value was 2.23±0.32 (significant positive correlation between age and the value of HI). Results of Mann- Whitney test did not demonstrate any difference between gender in the observed group. In the group of patients who were operated/diagnosed with pectus excavatum the average value of Haller index was 3.39 within the range of 2.23 to 5.72 (correlation between the age of these patients and Haller index was negative, but not significant). The dependence of the Haller index value and certain respiratory phase during which the CT scan was performed also was determined. Thus, the average value of Haller index in inspirium in children with diagnosed deformity was up to 2.69±0.76. In the same group of patients the value of Haller index in expirium was up to 3.49±1.19. Only 3/32 (9%) patients had HI value over 3.25 (a boundary value for surgical treatment) during inspirium, while 13/32 (41%) patients had it in expirium, this data showed statistically significant difference (χ2=6.250; df=1; p=0.012). Single-slice CT technique during the inspiratory and expiratory phase reduces 20-25 times the effective dose of ionizing radiation. Conclusion: The value of Haller index increases with the age, but its dependence on the gender was not determined. It is possible to change the way of CT verification of Haller index in preoperative preparation for the Nuss operation using the "single-slice" technique in exspiratory phase. In addition to Haller index it is useful to determine correction index, the index of asymmetry and the index of sternal rotation as well. This protocol is proposed for standard preoperative preparation and treatment of pediatric population with pectus excavatum with the aim of its application in daily work in institutions that deal with this problem, but also to improve the quality of diagnosis and treatment outcomes.