About The Author

Fellow Pediatric Anesthesia

Chief of Department

Dept. of Pediatric Anesthesia

BJ Wadia Hospital for Children, Mumbai, Maharashtra

Address for correspondence

Dr Sudivya Sharma

Flat No. 77, B-Wing, Mahavir Krupa Building

TJ Road, Sewri (W), Mumbai - 400 015, Maharashtra

ABSTRACT

Constriction band syndrome (CBS) or amniotic band syndrome is a group of congenital birth defects believed to be caused by entrapment of fetal parts (usually a limb or digits) in fibrous amniotic bands while in utero. The commonly accepted view is the extrinsic theory, that CBS occurs when the inner membrane (amnion) ruptures without injury to the outer membrane (chorion). The chorionic side of the amnion emanates numerous mesoblastic fibrous strings, which entrap and catch the fetal parts. On the other hand, the intrinsic theory proposed by George Streeter, explains the ring constrictions as areas of defectively formed tissue due to defective germ plasma areas, and due to the closeness to the amnion caused its connection. CBS not only causes esthetic deformity in the affected limb, but may also cause vascular compromise, which can lead to lymphedema and/or amputation. Concerning the treatment of congenital CBS, the use of Z-plasty or W-plasty after the excision of the constriction band, in a one- or two-stage approach is recommended.

Keywords: Constriction band syndrome, mesoblastic fibrous strings, defective germ plasma areas, lymphedema, amputation

Constriction band syndrome (CBS) or amniotic band syndrome is a group of congenital birth defects believed to be caused by entrapment of fetal parts (usually a limb or digits) in fibrous amniotic bands while in utero. Other names include amniotic band syndrome, also known as “Adam Complex”, Streeter’s dysplasia, annular groove, ring constriction syndrome and pseudoainhum. It has an incidence of one in 1,200 to one in 15,000 live births and affects both sexes at a ratio of 1:1. There is a significant predilection for the upper extremities and an increased frequency in distal limbs, and longer digits are significantly more involved than shorter ones.^1-6

THEORIES

The commonly accepted view is the extrinsic theory, that CBS occurs when the inner membrane (amnion) ruptures without injury to the outer membrane (chorion). The chorionic side of the amnion emanates numerous mesoblastic fibrous strings, which entrap and catch the fetal parts. This extrinsic theory was proposed by Richard Torpin, an obstetrician, in 1965.⁷ In some cases, complete “natural” amputation of a digit(s) or limb may occur before birth or the digit(s) or limbs may be necrotic (dead) and require surgical amputation following birth.

There is an intrinsic theory proposed by George Streeter, the director of embryology at Carnegie Institute, in 1930 which is called, “Streeter’s dysplasia”. He explained the ring constrictions as areas of defectively formed tissue due to defective germ plasma areas, and due to the closeness to the amnion caused its connection. This theory is supported by evidence of cases in which the infant affected is born with the amnion intact.⁸

PRESENTATION

The variable clinical manifestations of congenital CBS can best be explained as the response of the growing, embryologically defined limb to intrauterine deformation or band-induced compression and ischemia. In the hand, digital amputations are most common in the index, middle and ring fingers (Figs. 1 and 2), whereas in the foot, amputations of the hallux are most often noted. Band indentations are often present at multiple levels. Proximal bands may be associated with neural compression.

There are several features that are relatively consistent:

• Syndactyly
• Distal ring constrictions
• Deformity of the nails
• Stunted growth of the small bones in the digits
• Limb length discrepancy
• Distal lymphedema
• Congenital band indentations
• If a band wraps tightly around a limb, the limb can actually be completely amputated.
• A strong relationship between CBS and clubfoot exists.
• In 1961, Patterson used a classification that is still widely used today.⁴ The classifications are as follows:
• Simple ring constrictions
• Ring constrictions accompanied by deformity of the distal part with or without lymphedema
• Ring constrictions accompanied by fusion of distal parts ranging from mild-to-severe acrosyndactyly
• Intrauterine amputations.

MANAGEMENT

CBS not only causes esthetic deformity in the affected limb, but may also cause vascular compromise, which can lead to lymphedema and/or amputation. The treatment of CBS is therefore aimed at improvement of function and improvement of cosmetic appearance. Concerning the treatment of congenital CBS, most references recommend the use of Z-plasty or W-plasty after the excision of the constriction band, in a one- or two-stage approach.⁹ Very rarely if CBS is detected in utero, fetal surgery may be performed to save a limb or other deformity.

CONCLUSION

The future for those suffering from CBS is continually improving because of upcoming in utero surgical procedures. Regardless, what theory proves to be evident in causing CBS, it is extremely important to seek prenatal medical attention when pregnant. It is likely that genetic predisposing factors are involved, as can be inferred by the higher incidence of the syndrome in first-degree relatives of the affected individuals. No less important; however, appear to be acquired yearly factors, such as the use of drugs, tobacco, diabetes, known for their action on the vascular system or even iatrogenic factors like the sting from amniocentesis, which are an insult to the amniotic membranes.

REFERENCES

1. Foulkes GD, Reinker K. Congenital constriction band syndrome: a seventy-year experience. J Pediatr Orthop. 1994;14(2):242-8.
2. Al-Qattan MM. Classification of the pattern of intrauterine amputations of the upper limb in constriction ring syndrome. Ann Plast Surg. 2000;44(6):626-32.
3. Garza A, Cordero JF, Mulinare J. Epidemiology of the early amnion rupture spectrum of defects. Am J Dis Child. 1988;142(5):541-4.
4. Patterson TJ. Congenital ring-constrictions. Br J Plast Surg. 1961;14:1-31
5. Kino Y. Clinical and experimental studies of the congenital constriction band syndrome, with an emphasis on its etiology. J Bone Joint Surg Am. 1975;57(5):636-43.
6. Flatt AE. The Care of Congenital Hand Anomalies. St Louis: CV Mosby Company; 1977.
7. Torpin R. Amniochorionic mesoblastic fibrous rings and amniotic bands: associated constricting fetal malformations or fetal death. Am J Obstet Gynecol. 1965;91:65-75.
8. Streeter GL. Focal deficiencies in fetal tissues and their relation to intrauterine amputations. Contrib Embryol Carnegie Inst. 1930;22:1-44.
9. Wiedrich TA. Congenital constriction band syndrome. Hand Clin. 1998;14(1):29-38.