Comparison of Two- and Three-dimensional Ultrasonography in the Evaluation of Lesion Level in Fetuses with Spina Bifida

Abstract

Purpose To evaluate the precision of both two- and three-dimensional ultrasonography in determining vertebral lesion level (the first open vertebra) in patients with spina bifida.

Methods This was a prospective longitudinal study comprising of fetuses with open spina bifida who were treated in the fetal medicine division of the department of obstetrics of Hospital das Clínicas of the Universidade de São Paulo between 2004 and 2013. Vertebral lesion level was established by using both two- and three-dimensional ultrasonography in 50 fetuses (two examiners in each method). The lesion level in the neonatal period was established by radiological assessment of the spine. All pregnancies were followed in our hospital prenatally, and delivery was scheduled to allow immediate postnatal surgical correction.

Results Two-dimensional sonography precisely estimated the spina bifida level in 53% of the cases. The estimate error was within one vertebra in 80% of the cases, in up to two vertebrae in 89%, and in up to three vertebrae in 100%, showing a good interobserver agreement. Three-dimensional ultrasonography precisely estimated the lesion level in 50% of the cases. The estimate error was within one vertebra in 82% of the cases, in up to two vertebrae in 90%, and in up to three vertebrae in 100%, also showing good interobserver agreement. Whenever an estimate error was observed, both two- and three-dimensional ultrasonography scans tended to underestimate the true lesion level (55.3% and 62% of the cases, respectively).

Conclusions No relevant difference in diagnostic performance was observed between the two- and three-dimensional ultrasonography. The use of three-dimensional ultrasonography showed no additional benefit in diagnosing the lesion level in the fetuses with spina bifida. Errors in both methods showed a tendency to underestimate lesion level.

Resumo

Objetivo Avaliar a precisão da ultrassonografia bidimensional e tridimensional para a determinação do nível da lesão vertebral em casos de fetos portadores de espinha bífida.

Métodos Estudo prospectivo longitudinal, compreendendo fetos portadores de espinha bífida assistidos no setor de medicina fetal de hospital de ensino do Sudeste do Brasil, entre os anos de 2004 e 2013. Foram incluídos 50 fetos portadores de espinha bífida pela ultrassonografia bidimensional e tridimensional (dois examinadores em cada método) com relação ao nível da lesão. O nível exato da lesão foi verificado usando radiografia após o nascimento.

Resultados A ultrassonografia bidimensional estimou corretamente o nível de espinha bífida em 53,0% dos casos. Em 80,0% dos casos a estimativa ocorreu com erro de uma vértebra; 89,0% em até duas vértebras e de 100,0% em até três vértebras. A ultrassonografia tridimensional estimou corretamente o nível de espinha bífida em 50,0% dos casos. Em 82,0% dos casos, a estimativa ocorreu com erro de uma vértebra; 90,0% em até duas vértebras e de 100,0% em até três vértebras. Nos casos em que houve erro na estimativa do nível da lesão, tanto na avaliação bidimensional quanto na tridimensional, observou-se tendência a subestimar o nível da lesão vertebral (55,3% na avaliação bidimensional e 62,0% na tridimensional), ou seja, colocando o nível ultrassonográfico mais baixo que o observado no pós-natal.

Conclusões Não houve diferenças relevantes entre o desempenho diagnóstico da ultrassonografia bidimensional e tridimensional para determinação do nível da lesão vertebral nos casos de fetos portadores de espinha bífida. Tendência a subestimação do nível de lesão nos casos em que houve erro tanto na ultrassonografia bidimensional quanto na tridimensional.

Keywords

fetus - two-dimensional ultrasonography - three-dimensional ultrasonography - spina bifida

Palavras-chave

fetos - ultrassom bidimensional - ultrassom tridimensional - espinha bífida

• References

• 1 American College of Obstetricians and Gynecologists. ACOG technical bulletin no. 99: prenatal detection of neural tube defects. Washington (DC): ACOG; 1986
• 2 Wegner C, Nau H. Alteration of embryonic folate metabolism by valproic acid during organogenesis: implications for mechanism of teratogenesis. Neurology 1992; 42 (4) (Suppl. 05) 17-24
• 3 McDonnell R, Johnson Z, Doyle A, Sayers G. Determinants of folic acid knowledge and use among antenatal women. J Public Health Med 1999; 21 (2) 145-149
• 4 Wald NJ, Law MR, Morris JK, Wald DS. Quantifying the effect of folic acid. Lancet 2001; 358 (9298) 2069-2073
• 5 Bruner JP, Tulipan N, Paschall RL , et al. Fetal surgery for myelomeningocele and the incidence of shunt-dependent hydrocephalus. JAMA 1999; 282 (19) 1819-1825
• 6 Hirose S, Farmer DL, Albanese CT. Fetal surgery for myelomeningocele. Curr Opin Obstet Gynecol 2001; 13 (2) 215-222
• 7 Bruner JP, Tulipan NE, Richards WO. Endoscopic coverage of fetal open myelomeningocele in utero. Am J Obstet Gynecol 1997; 176 (1 Pt 1): 256-257
• 8 Adzick NS, Thom EA, Spong CY , et al; MOMS Investigators. A randomized trial of prenatal versus postnatal repair of myelomeningocele. N Engl J Med 2011; 364 (11) 993-1004
• 9 Meuli M, Moehrlen U. Fetal surgery for myelomeningocele is effective: a critical look at the whys. Pediatr Surg Int 2014; 30 (7) 689-697
• 10 Flake A. Percutaneous minimal-access fetoscopic surgery for myelomeningocele - not so minimal!. Ultrasound Obstet Gynecol 2014; 44 (5) 499-500
• 11 Adzick NS. Fetal surgery for spina bifida: past, present, future. Semin Pediatr Surg 2013; 22 (1) 10-17
• 12 Okumura M, Zugaib M. Ultra-Sonografia em obstetrícia. São Paulo: Sarvier; 2002
• 13 Orlandi E, Rossi C, Perino A, Cucinella G, Orlandi F. Prospective sonographic detection of spina bifida at 11-14 weeks and systematic literature review. J Matern Fetal Neonatal Med 2015; 1-5 [Epub ahead of print]
• 14 Chaoui R, Benoit B, Mitkowska-Wozniak H, Heling KS, Nicolaides KH. Assessment of intracranial translucency (IT) in the detection of spina bifida at the 11-13-week scan. Ultrasound Obstet Gynecol 2009; 34 (3) 249-252
• 15 Bruner JP, Tulipan N, Dabrowiak ME , et al. Upper level of the spina bifida defect: how good are we?. Ultrasound Obstet Gynecol 2004; 24 (6) 612-617
• 16 Buyukkurt S, Binokay F, Seydaoglu G , et al. Prenatal determination of the upper lesion level of spina bifida with three-dimensional ultrasound. Fetal Diagn Ther 2013; 33 (1) 36-40
• 17 Cameron M, Moran P. Prenatal screening and diagnosis of neural tube defects. Prenat Diagn 2009; 29 (4) 402-411
• 18 Lee W, Chaiworapongsa T, Romero R , et al. A diagnostic approach for the evaluation of spina bifida by three-dimensional ultrasonography. J Ultrasound Med 2002; 21 (6) 619-626
• 19 Carletti A, Ghi T, Ceccarini M , et al. OC160: three-dimensional ultrasonography is of limited value in diagnosing fetal spina bifida. Ultrasound Obstet Gynecol 2007; 30 (4) 416
• 20 Wei Q, Cai A, Wang X, Xie L, Wang B, Wang X. Value of 3-dimensional sonography for prenatal diagnosis of vertebral formation failure. J Ultrasound Med 2013; 32 (4) 595-607
• 21 Rosner BA. Fundamentals of biostatistics. 4th ed. Belmont: Duxbury Press; 1995
• 22 Kollias SS, Goldstein RB, Cogen PH, Filly RA. Prenatally detected myelomeningoceles: sonographic accuracy in estimation of the spinal level. Radiology 1992; 185 (1) 109-112
• 23 Verbeek RJ, van der Hoeven JH, Maurits NM, Brouwer OF, Hoving EW, Sival DA. In spina bifida aperta, muscle ultrasound can quantify the “second hit of damage”. Childs Nerv Syst 2013; 29 (3) 469-474