Streeter Dysplasia Treatment & Management

Because amniotic band syndrome is an intrauterine phenomenon probably caused by the rupture of amniotic membranes and constriction of the developing tissue, no medical treatment exists for the condition. Avoiding certain drugs that can lead to spontaneous rupture of membranes, such as cocaine and mifepristone, may help decrease the potential risk.

Due to tight constrictions on the digits or extremities, urgent surgical treatment often is necessary for patients with vascular compromise. Surgery also is indicated for patients with syndactyly or acrosyndactyly that compromises hand function. Thumb amputation (which is rare), clubfeet, cleft lip, and cleft palate also require reconstruction, but these procedures can be performed electively at a later time and at the discretion of the physician and family.^[25]

In bands identified by 3-D ultrasound to cause neurovascular compromise, early in utero fetoscopic surgery for release can be performed. Early results in animal models and in selected case series are promising.^{[26, 27, 28]}

Early intervention for severe constriction bands after birth includes band excision with 1-2 mm of normal skin to avoid recurrence. The entire band requires excision. This is performed on a maximum of 65% of the ring (most authors recommend 50%) by Z-plasty for lesser constrictions and by V-Y plasty or W-plasty for tighter bands. A staged correction ensures adequacy of vascularity to the residual limb or digit. Additionally, debulking the fibrofatty soft tissues followed by subcutaneous tissue advancement as described by Upton^[29] may further improve the cosmetic appearance of the digits after band release. For a study of the formation of phalanges and small joints through tissue engineering, see the work of Isogai and coworkers.^[30]

For severely constricted bands with wide tissue excision, W-plasty is preferred to provide additional skin for closure. In band excision, intraoperative consideration should be given to possible attenuation of the neurovascular bundle and its proximity to the surface of the band. Careful dissection under magnifying loupes prevents possible damage to these vital structures.

The first part of acrosyndactyly release is separation of the digits, especially if the constricting rings are not compromising circulation. Digits are separated when infants are aged 6 months to 1 year. Dobyns reported that the number of fingers is not as important as their length, bulk, stability, spacing, and control.^[31] The groin is prepared for skin graft harvest, which will be necessary for closure. Reconstruction typically is performed in a proximal-to-distal direction and requires complete removal of the sinus tracts, as these tend to be located more distally than are the normal web spaces. If the thumb is severely shortened or its function is compromised, the on-top plasty or toe-to-thumb transfer may be considered. Despite cosmetic improvements, the digits will continue to be stiff.

Intrauterine amputations do not need intervention unless they involve the thumb at the metacarpophalangeal (MCP) joint. In these cases, the on-top plasty or toe-to-thumb transfer may improve function.

In the lower extremities, teratologic clubfeet associated with deep congenital constriction bands usually require constriction band excision, Z-plasty, and posteromedial release and casting. This is typically described as a staged procedure. The band excision and Z-plasty may be performed in parts (3-stage clubfoot release) or in full (2-stage clubfoot release).^[32] Performing the procedure in staged parts was previously considered necessary to avoid any vascular compromise with the clubfoot surgery, skin sloughing, and infection. Greene,^[33] however, has published good results in 3 patients with 4 affected clubfeet who were treated with band excision, Z-plasty, and posteromedial release in a single full procedure with no significant complications. The benefits of a single complete procedure include ease of postoperative patient care and reduced patient exposure to general anesthetics.

All patients with amniotic band syndrome should be monitored regularly until skeletal maturity because of the potential for recurrence of the rings and for secondary contractures that may develop and must be addressed on an individual basis.

Complications from amniotic band syndrome include severe lymphatic or venous congestion at the time of birth due to tight bands. This congestion may lead to necrosis and gangrene^[13] if not urgently treated with excision and release. Other potential complications include neurovascular compromise caused by release of the entire band at one sitting or lack of attention to the superficial level of the attenuated nerves and vessels.

Clubfeet are teratologic in 50% of cases and do not respond well to surgical posteromedial releases alone. The constriction bands often require excision, and tendon transfers may be required later because of peroneal nerve compromise.

The prognosis for the isolated superficial extremity bands is good (see image below). Aside from cosmetic variability, no functional deficits remain.

Deeper bands may be associated with progressive problems leading to later lymphatic and neurovascular compromise that requires surgery. For patients with acrosyndactyly, hand function is limited secondary to stiffness of the joints, but good prehension and grasp may be obtained with reconstructive procedures. Children who have had intrauterine amputations are usually well adapted to their physical limitations, and often little needs to be done. In children with a transverse deficiency proximal to the ankle joint, a prosthesis is required for full function.

Today, expecting parents are able to determine a lot about their child before birth. Obstetric ultrasound is currently the most common method to identify amniotic band syndrome in the prenatal period. When the new family is confronted with knowledge of a deformed neonate, whether the deformity is anencephaly or cleft lip and palate, controversy still exists as to the next step. Should the option for termination be offered, or should families be allowed to attempt to selectively produce the perfect child? This is an ethical debate that still has no final answer.