Clinical and experimental studies of the congenital constriction band syndrome, with an emphasis on its etiology

Clinical Manifestations of Constriction Band Syndrome

BACKGROUND

Constriction band syndrome (CBS) is a congenital limb anomaly with varying presentation. We sought to characterize the clinical manifestations of CBS by analyzing a large cohort of patients. Our secondary aim was to evaluate potential risk factors for CBS.

METHODS

We retrospectively reviewed the records for all patients with CBS who had presented to our tertiary medical center between 1998 and 2018. Examination by a pediatric orthopaedic surgeon and the presence of pathognomonic features were inclusion criteria. Clinical notes, photographs, and radiographs were reviewed to determine the pattern of limb involvement and associated conditions. Demographic data were compared with population averages to assess for possible risk factors.

RESULTS

One hundred and twenty-eight children were included. The most prevalent feature was constriction bands (96%), followed by limb or digit amputations (88%) and syndactyly/acrosyndactyly (69%). Children without constriction bands presented with either acrosyndactyly or growth of an osseous spike from a congenital diaphyseal limb or digit amputation. There was a strong predilection for involvement of central digits of the hands and feet, with sparing of the thumb/great toe and small finger/toe. The average number of involved limbs per child was 2.6; 23% of the children had involvement of only 1 limb. Children with at least 1 additional diagnosis had more limbs affected by CBS than those who were otherwise healthy (2 limbs [interquartile range (IQR), 1-3 limbs] versus 3 limbs [IQR, 2-4 limbs]; p = 0.006), suggesting a more severe phenotype. Children with more limbs involved underwent more surgical procedures (p < 0.001). CBS was associated with gestational trauma, prematurity, low birth weight, young and old maternal age, and higher social deprivation.

CONCLUSIONS

Children with CBS can be categorized as having either mild or extensive involvement based on the number of involved limbs and associated conditions. Future investigation of prenatal risk factors is necessary to further elucidate the etiology of this heterogenous condition.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Ponseti Method for the Treatment of Clubfeet Associated With Amniotic Band Syndrome: A Single Institution 20-Year Experience

BACKGROUND

Amniotic band syndrome (ABS) is a congenital disorder resulting in fibrous bands that can cause limb anomalies, amputations, and deformities. Clubfoot has been reported in up to 50% of patients with ABS. The purpose of this study is to compare treatment characteristics and outcomes of clubfoot patients with ABS to those with idiopathic clubfoot treated with the Ponseti method.

METHODS

An Institution Review Board (IRB) approved retrospective review of prospectively gathered data was performed at a single pediatric hospital over a 20-year period. Patients with either idiopathic clubfeet or clubfeet associated with concomitant ABS who were <1 year of age and treated by the Ponseti method were included. Initial Dimeglio score, number of casts, need for heel cord tenotomy, recurrence, and need for further surgery were recorded. Outcomes were classified as "good" (plantigrade foot±heel cord tenotomy), "fair" (need for a limited procedure), or "poor" (need for a full posteromedial release).

RESULTS

Forty-three clubfeet in 32 patients with ABS, and 320 idiopathic clubfeet in 215 patients were identified. Average age at last follow up was not different between ABS and idiopathic cohorts (7.4 vs. 5.2 y, P=0.233). Average Dimeglio score was lower in the ABS cohort (12.3 vs. 13.7, P=0.006). Recurrence rate was significantly higher in the ABS (62.8%) compared with idiopathic cohort (37.2%) (P=0.001). Clinical outcomes were significantly better in the idiopathic cohort (69.4% "good", 26.9% "fair", 3.8% "poor") compared with the ABS cohort (41.9% "good", 34.9% "fair", and 23.3% "poor") (P<0.001). Within the ABS cohort, no significant differences in clinical outcomes were found based upon location, severity, or presence of an ipsilateral lower extremity band.

CONCLUSION

Clubfeet associated with ABS have higher rates of recurrence, a greater need for later surgery, and worse clinical outcomes than idiopathic clubfeet. This information may prove helpful in counseling parents of infants with ABS associated clubfeet.

LEVEL OF EVIDENCE

Level III.

Single-Stage Resection of Type II Constriction Rings in Limbs on the Basis of Histologic and Magnetic Resonance Imaging Observations: A Retrospective Study of 21 Consecutive Patients

BACKGROUND

The purpose of this study was to determine the feasibility of single-stage resection for type II congenital constriction rings by means of histologic examination of resected specimens and imaging examination of affected extremities, and to evaluate the appearance and function of the extremities after single-stage surgery.

METHODS

The features of the skin on the constriction rings and the subcutaneous tissues were identified through continuous sectioning, hematoxylin and eosin staining, and immunohistologic staining of specimens of type II constriction rings obtained by means of surgery. The relationship between the constriction rings and the deep main blood vessels was evaluated using magnetic resonance imaging. Single-stage resection of the constriction band, reduction of the fascial flap, and triangular flap-plasty were performed for 21 patients. The appearance, lymphedema, and movement of the extremities were compared before and after the operation.

RESULTS

Type II constriction rings in the extremities had normal full-layer skin structures. Collagen was found deposited densely at the base of the grooves, but the normal subcutaneous tissue space remained, and the vital nerves and blood vessels were unaffected. Complete resection of the constriction rings was achieved in all 21 patients, and lymphedema subsided 2 months after the operation. No episode of recurrence was found, and limb function was not affected at 26-month follow-up.

CONCLUSIONS

Type II congenital constriction rings in limbs possess normal subcutaneous tissue spaces. A single-stage operation, which includes complete resection of the rings, fascial flap reduction, and triangular flap-plasty, could achieve a satisfactory appearance and good function.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Management of the Amniotic Band Syndrome with Cleft Palate: Literature Review and Report of a Case

Amniotic Band Syndrome (ABS) is a group of congenital malformations that includes the majority of typical constriction rings and limb and digital amputations, together with major craniofacial, thoracic, and abdominal malformations. The syndrome is caused by early rupture of the amniotic sac. Some of the main oral manifestations include micrognathia, hyperdontia, and cleft lip with or without cleft palate, which is present in 14.6% of patients with this syndrome. The purpose of this report was to describe the clinical characteristics and the oral treatment provided to a 6-month-old male patient affected with ABS with cleft lip and palate.

The Effectiveness of the Ponseti Method for Treating Clubfoot Associated With Amniotic Band Syndrome

BACKGROUND

Amniotic band syndrome (ABS) is a congenital disorder with an associated incidence of clubfoot deformity in over 50% of patients. Although early reports in the literature demonstrated a poor response to casting treatments, recent application of the Ponseti technique in ABS patients have been more promising.

METHODS

A retrospective review of all patients with clubfoot and a concurrent diagnosis of ABS were reviewed at a single institution. Patients not managed initially with the Ponseti method were excluded. Data collected included patient age at presentation, sex, unilateral or bilateral, amniotic band location and associated findings, and response to treatment-number of casts and requirement of Achilles tenotomy, tibialis anterior tendon transfer, or other surgical procedures. Duration of treatment at latest follow-up visit was noted and outcome was based on clinical foot appearance and plan for any further procedures.

RESULTS

Twelve patients (7 female and 5 male) with a total of 21 feet (9 bilateral and 3 unilateral) were identified. The average age at presentation was 3 weeks (range, 1 to 9 wk). The average number of casts was 6 (range, 3 to 11). Seventeen of 21 feet (81.0%) underwent percutaneous Achilles tenotomy. The initial correction rate for all patients with the Ponseti technique was 20/21 feet (95.2%) and recurrence was noted in 7/21 feet (33.3%). One patient underwent primary posteromedial release and 2 patients had associated neurological deficits. The average follow-up was 3.9 years (range, 9 mo to 10 y) and all but one patient had supple, plantigrade feet.

CONCLUSION

The Ponseti technique is an effective first-line treatment in patients who have clubfeet associated with ABS, including those with a neurological deficit.

LEVEL OF EVIDENCE

Level IV.

An Alternative Surgical Approach to Pseudoainhum: A Case Report

Pseudoainhum is a disorder of unknown etiology that is usually congenital and nonprogressive. One theory states it is caused by amnion band constriction in utero. These constriction bands lead, not only to a less cosmetically appealing foot, but also to long-term neurovascular compromise, resulting in amputation of the digit. The described surgical approaches have been limited within published data. The 2 procedures that have been described are either a Z-plasty or amputation, depending on the degree of the deformity. The present case report provides an alternative surgical approach to a pseudoainhum deformity of a third digit.

ADAM "sequence" part II: hypothesis and speculation

Noted for centuries in humans, a relatively hairless mammal [e.g., Hallero, 1766; Hohl, 1828 in Klunker, 2003], the so-called amniotic deformities, adhesions, mutilations (ADAM) sequence remains causally and pathogenetically incognito. In 1930 Streeter stated " apodictically" that no evidence has been found that intra-uterine amputation is due to amniotic bands or adhesions …" and that his 16 cases provided (histological) evidence for a "germinal origin." He concluded that an amniotic cord was "not an adhesion or inflammatory product but … an anomalous developmental structure and present from the outset." In survivors the "traces" of damaged limb-buds "reveal the scars of poor germ-plasm." In 1958, Willis, in dismissing the amniotic origin of the ADAM defects (or "Streeter" or "Simonart" bands) quoted Keith [1940] to the effect that "(a)mniotic adhesions … are always produced by … the fetus – as a result of dysplasia in foetal tissues. They are the result, not the cause, of foetal malformations." Streeter [1930] mentions a potential familial case (56-year-old man and his mother), not controlled by photographs or other records and concluded "that the (ADAM) deformity is not easily transmissible," but "due to the constitution of the germ-plasm." Torpin [1968] concluded, as apodictically as Streeter and Willis, that "… proof of amnion rupture without damage to the chorionic sac is no longer "in question." Considering Torpin's decades-long study of the ADAM phenomenon and review of 494 references (missing many) it is surprising that he does not discuss the relationship between the apparent ADAM defects and other, internal anomalies that maybe present in an affected fetus or infant not evidently caused by the amniotic disruptions, adhesions or mutilations, unless his mind was made up. Our review of these internal and other presumed primary malformations in ADAM is ongoing. However, on a preliminary basis, it seems likely to us that: (1) there is an increased prevalence of such primary anomalies in the ADAM condition confirming the view and experience of others, for example Czeizel et al. [1993]; (2) these malformations (e.g., heterotaxy) may arise as early as gastrulation; (3) that, given the ADAM phenomenon is exclusively ascertained as the ADAM phenotype in fetuses and infants, that is, that its cause and ascertainment are completely congruent, then the apparent amniotic defect must also be regarded as a malformation; (4) that in such a case the ADAM phenomenon with associated primary malformation(s) is a form of syndromal pleiotropy due to one cause yet to be elucidated. To that end we recommend archiving DNA from all affected fetuses coming to autopsy and their parents and placentas and surgical tissues of all viable affected infants for ultimate exome or genome sequencing perhaps with special attention to the syncytin genes.

Congenital constriction band syndrome with limb defects

BACKGROUND

The purpose of this study was to clarify the spectrum of congenital constriction band syndrome (CBS) and associated anomalies and mortality in Finland.

METHODS

Register-based data were analyzed for children with congenital constriction bands in upper and lower extremities as a part of an ongoing study on 419 upper limb defects and 171 lower limb defects occurring among 753,342 births in Finland during 1993 to 2005.

RESULTS

A total of 71 cases with limb CBS were identified during the 13-year study period. The birth prevalence was 0.9 per 10 000 births (1:10 600). Infant mortality was 4.6% (3/65) and perinatal mortality 12.7% (9/71). In 35 cases (49%) only upper limbs were affected and in 13 cases (18%) there were constriction defects only in lower limbs. In 23 cases (32%) both upper and lower limbs were involved. None of the cases associated with a known syndrome. However, in 21 cases (30%) the child had other anomalies associated with constriction rings: pes equinovarus in 8/21, cleft palate in 5/21, congenital heart defect in 6/21, and other anomalies in 14/21. Eighteen (25%) had low birth weight, 22 (31%) were born preterm, and 8 children (11%) were small for gestational age. Children with associated anomalies showed higher mortality, shorter duration of gestation, and lower birth weight.

CONCLUSIONS

CBS is rare and comprises approximately 12% of all congenital upper limb defects and 14% of lower limb defects. Other skeletal and nonskeletal anomalies are present in 30% of the affected children, suggesting a possible genetic etiology. More detailed characterization of the children with associated anomalies may shed light to the pathogenetic mechanisms of this syndrome.

LEVEL OF EVIDENCE

Population-based register study/II.

[Complex of amniotic deformities, adhesions, mutilations: Endless debate]

Amniotic deformities, adhesions, mutilations (ADAM) complex is a broad heterogeneous spectrum of congenital anomalies. ADAM complex is characterized by constriction rings, amputation of fingers or limbs and the presence of the amniotic band. However, it may also involve craniofacial disruptions, body wall defects and internal organ abnormalities. The aim of this review is to present the results found in regard to ADAM complex from its historical background, clinical manifestations, epidemiology, etc. In particular, our attention was focused on demonstrating the varying etiopathogenesis theories of ADAM complex and their contradictions. The study was conducted using the databases of PubMed, EBSCO host, Ovid, SpringerLink, Scopus, nature.com, JAMA and ScienceDirect with the following keywords for the search: "amniotic band syndrome", "amniotic band sequence", "Streeter dysplasia", "ADAM complex". In this study we used 22 full-text articles. Patients with ADAM complex require a complete pre- and postnatal evaluation to integrate the diagnosis and to decide on timely treatment. It is important for clinicians and surgeons to possess knowledge of this entity. Further research is necessary to establish a nosological basis.

Flail extremity resulting from constriction band syndrome: Neurovascular implications and surgical management

Purpose: Constriction band syndrome afflicting in utero development can lead to devastating and possibly fatal outcomes. A lack of consensus regarding noninvasive testing and surgical modalities is likely secondary to the continued poorly understood pathology. Methods: We provide a case report of a 6-month-old boy who presented with a functional, nonsensate upper limb after surgical release of midhumeral banding at 3 months of age. Results: Exploration revealed intact, albeit atrophic, peripheral nerves with brachial artery disruption above the elbow. Sural nerve grafting was performed and 2-year follow-up demonstrated return of protective sensation in the median nerve distribution with minimal motor return. Conclusion: This case demonstrates that nerves present distal to the original soft tissue insult oppose the idea of failure of nerve formation. Early nerve grafting at the time of initial Z-plasty release may serve to improve long-term functional outcomes.

The use of the Ponseti method to treat clubfeet associated with congenital annular band syndrome

BACKGROUND

A clubfoot deformity may be associated with congenital annular band syndrome (CABS), and has, until recently, been thought to be resistant to nonoperative management. The purpose of this report was to describe the use of the Ponseti method in the treatment of 5 patients whose clubfeet were associated with this syndrome.

METHODS

All patients with a diagnosis of clubfoot, who were treated at the Orthopaedic Hospital Clubfoot Clinic, over a period of 4 years, were reviewed. During that period, a total of 131 infants with 194 clubfeet were treated. We identified 5 infants (3.8%) with 6 clubfeet associated with CABS. The patients were managed using the Ponseti method. One of the patients, with a contralateral amputation of the limb opposite to the side with a clubfoot, required the use of a unilateral foot abduction orthosis rather than a conventional foot abduction orthosis. The outcomes evaluated included: the number of casts needed to obtain correction, the percentage of patients requiring a tendo-Achilles tenotomy, the number of relapses, and the need for additional secondary procedures.

RESULTS

The mean age at presentation for the 5 patients was 6.2 weeks. Four of the clubfeet had an ipsilateral band and 2 did not. None of the patients had a neurological deficit distal to a band. The mean number of casts used to correct the deformity was 6, and a percutaneous tendo-Achilles tenotomy was done in all cases. All of the feet achieved initial correction. Four patients (5 feet) experienced a relapse attributed to failure to use the postcorrective brace as prescribed. Correction of the foot in 3 of these patients was regained and maintained by another series of manipulation and cast application followed by resumption of bracing. One patient underwent an anterior tibial tendon transfer. The patients were followed for an average of 32.6 months (21 to 49 mo). All feet were supple and plantigrade at latest follow-up evaluation.

CONCLUSIONS

The Ponseti method may be successfully applied to clubfeet associated with CABS.

LEVEL OF EVIDENCE

Level IV.

Development of a fetal rabbit model to study amniotic band syndrome

Amniotic band syndrome (ABS) is a group of fetal malformations caused by fibrous adherences. Species such as sheep, rats, and mice have been used to study this syndrome. We developed a fetal rabbit model using 24 fetuses from punctured uteri. We found one case of syndactyly, one case of amniotic banding, two cases of extremity deformities, one case of a tail deformity, one case of head compression, and one case of open eyelids. Other malformations have been described in an amnion rupture sequence model (exencephaly and cleft palate). The rabbit fetus is an adequate model in which to develop this syndrome.

Metacarpal hypoplasia associated with congenital constriction band syndrome

PURPOSE

The amputation of digits that occurs in association with congenital constriction band syndrome (CCBS) is often described as similar to that resulting from trauma. Some previous studies have suggested that no bone hypoplasia is present in the affected limb proximal to the amputated part. The purpose of this study was to report our series of patients with metacarpal hypoplasia in amputated digits associated with CCBS.

METHODS

We reviewed a total of 37 hands of 24 patients diagnosed as having amputated fingers owing to CCBS and evaluated the clinical features of the metacarpal bone hypoplasia.

RESULTS

We found coexistent metacarpal hypoplasia in 11 hands in 9 patients. Three of the patients were male and 6 were female. The average age at the time of examination was 9 years (range, 4-20 y). We observed metacarpal hypoplasia in cases of amputation at the level of the proximal phalanx and not at the level of the middle phalanx.

CONCLUSIONS

We found metacarpal hypoplasia in 38% of patients and in 30% of hands with amputated digits owing to CCBS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

TRIANGULAR FLAPS: A MODIFIED TECHNIQUE FOR THE CORRECTION OF CONGENITAL CONSTRICTION RING SYNDROME

Congenital constriction ring syndrome (CCRS) is a congenital anomaly with a wide spectrum of clinical presentation. The accepted method of correcting a circular constriction is to excise the deep part of the constriction, and break the line of the circular scar with multiple Z- or W-plasties. Specific correction of soft tissue is recommended concurrently, to better correct the "sandglass" deformity. Here we describe a new technique using triangular advancement flaps to correct the deformity in eight patients with constriction ring syndrome, involving either the upper or lower limbs. In this technique, triangular flaps can be introduced either proximal or distal to the ring, depending on the limb circumference, to correct the contour deformity. In all eight patients, a normal extremity contour was obtained, with complete elimination of the deformity caused by the constriction ring. A mean follow-up of 43 months revealed an aesthetically acceptable scar, with no case of recurrence. Triangular flaps designed either proximal or distal to the constriction ring is able to correct the contour deformity of the limbs with great versatility and acceptable aesthetic results.

Limb-body wall defect. Is there a defensible hypothesis and can it explain all the associated anomalies?

Aside from gastroschisis and omphalocele, major defects of the ventral body (thoracoabdominal) wall are relatively uncommon and almost universally lethal. They are most often associated with other anomalies including those of the limbs that may range from amelia to mild positional deformations, unusual craniofacial malformations, and a variety of visceral abnormalities that include the heart, lungs, genitourinary system, and gut. This complex of ventral wall anomalies has been discussed under a broad and changing nomenclature that has included amniotic band disruption complex, amnion rupture sequence, limb-body wall defect (or complex), and simply body wall complex. Three major theories have been suggested to explain this complex: early amnion rupture (operating through uterine pressure and/or disruption by amniotic bands), vascular compromise (primarily hypoperfusion), and an early intrinsic defect of the developing embryo. We present four patients that illustrate the spectrum of ventral body wall defects, and from there critique the current hypotheses of pathogenesis. We conclude that this association of malformations originates as early as the embryonic disc stage, and that some of the observed associated anomalies are secondary complications of the primary disturbance in embryogenesis. We propose a new explanation for the atypical facial clefts and cranial malformations that are often observed.

Constriction band syndrome occurring in the setting of in vitro fertilization and advanced maternal age

The debate as to the pathogenesis of constriction band syndrome began with Hippocrates and continues today. The exogenous theory attributes the condition to entanglement of the fetus in the amniotic remnants following premature rupture of the amnion, which is in contrast to the endogenous, or genetic, mechanism.A case of constriction band syndrome in the setting of in vitro fertilization, where the child was genetically unrelated to the birth mother, is presented. Constriction band syndrome has been reported following amniocentesis and chorionic villus sampling, but it has not heretofore been presented in the setting of in vitro fertilization. In addition, the present case presents an opportunity to separate maternal from genetic factors and, possibly, shed some light on the etiology of the condition.

Congenital upper limb deficiencies and associated malformations in Finland: a population-based study

PURPOSE

To calculate the national incidence of upper limb deficiencies and associated infant mortality in children in Finland using the International Federation of Societies for Surgery of the Hand (IFSSH) classification. Radial ray deficiency, ulnar ray deficiency, central ray deficiency, transverse arrest, phocomelia, undergrowth, and constriction band syndrome with skeletal defects were evaluated.

METHODS

We reviewed upper limb deficiencies among all 753,342 births in Finland during 1993 to 2005 reported to the Finnish Register of Congenital Malformations. Classification of these upper limb deficiencies was done according to a modified IFSSH system. We calculated incidence, gender and side distributions, frequency of associated anomalies, and infant mortality rates in different subtypes of the deficiencies. Familial occurrence of congenital upper limb defects was recorded.

RESULTS

A total of 419 cases (234 male, 185 female) of upper limb deficiencies were identified. The national incidence of upper limb deficiencies was 5.56 per 10,000 births and 5.25 per 10,000 live births. The most common upper limb abnormality was radial ray deficiency (138), followed by subgroups of undergrowth (91), upper limb defects due to constriction band syndrome (51), central ray deficiency (41), and ulnar ray deficiency (33). Perinatal mortality was 14%. Infant mortality among children with upper limb deficiencies was 137 per 1,000 live births, compared with an overall infant mortality of 3.7 per 1,000 live births in Finland. Additional birth defects were found in 60% of these children. Prevalence of upper limb defects in relatives of the census population was 2% (11 of 419).

CONCLUSIONS

The national incidence of upper limb deficiencies is 5.25 per 10,000 live births. Congenital upper limb deficiencies are associated with additional birth defects in two thirds of cases. These children, especially children with radial ray deficiency, have a high perinatal mortality rate. When divided into subgroups using IFSSH classification, differences emerge in both associated anomalies and mortality.

Treatment of common congenital hand conditions

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Recognize the clinical features associated with five common congenital hand conditions. 2. Describe the indications and appropriate timing for various surgical procedures used to treat congenital hand anomalies. 3. Identify the pearls and pitfalls of these surgical treatments to avoid complications. 4. Understand the expected postoperative outcomes associated with these surgical procedures.

SUMMARY

This article provides an introduction to congenital hand differences by focusing on practical surgical strategies for treating five commonly encountered conditions, including syndactyly, constriction ring syndrome, duplicated thumb, hypoplastic thumb, and trigger thumb. The accompanying videos demonstrate common and reliable surgical techniques for syndactyly release, duplicated thumb reconstruction, and pollicization for hypoplastic thumb.

Constriction ring syndrome

Constriction ring syndrome is a congenital anomaly with sometimes devastating consequences. Because of the unknown etiology, treatment is aimed at recovery of function and prevention of the sequelae rather than prevention of the syndrome. This paper aimed to review the theories of the etiology, the features and associated defects, and the operative management of constriction ring syndrome.

Constriction band syndrome

Constriction band syndrome is an uncommon congenital abnormality with multiple disfiguring and disabling manifestations. Early amnion rupture with subsequent entanglement of fetal parts by amniotic strands is currently the primary theory for the development of this syndrome. Management of constriction band syndrome is focused on improving function and development while providing a more acceptable esthetic appearance. The treatment should be tailored to the individual. Timing of repair and surgical planning are important to provide the best functional results for affected hands.

Maternal vasoactive exposures, amniotic bands, and terminal transverse limb defects

BACKGROUND

Limb reduction deficiencies that are accompanied by amniotic bands (AB-Ls) and terminal transverse limb deficiencies (TLDs) have each been attributed to vascular disruption; for the former, however, it is not clear if amniotic bands are the primary cause of or are secondary to vascular disruption. If amniotic bands are secondary to vascular disruption, then a shared pathogenesis for each case group might be exhibited by similar risk factors.

METHODS

We evaluated maternal age, education, race/ethnicity, parity, pregnancy wantedness, and vasoactive exposures among 139 AB-L and 373 TLD cases, using interview data collected from mothers in 10 states by the National Birth Defects Prevention Study. Vasoactive exposures included maternal cigarette smoking and use of decongestants, nonsteroid anti-inflammatory drugs, and antihypertensive drugs in the periconceptional period.

RESULTS

Increased risk estimates were observed for Black mothers (OR 2.5; 95% CI: 1.5-4.1) and nulliparous mothers (2.1; 1.4-3.0) in relation to AB-L, while neither was associated with TLD. Hispanic women (1.4; 1.0-1.9) and those not wanting the pregnancy (1.5; 1.1-2.1) had increased risks of TLD, but not AB-L. Maternal cigarette smoking and aspirin use each increased the risk of AB-L, but not TLD; while decongestants and possibly antihypertensive medications increased the risk of TLD, but not AB-L.

CONCLUSIONS

The lack of consistent findings for the two case groups suggests that AB-L and TLD may be distinct entities. The inconsistencies also suggest that these vasoactive exposures may not be markers for vascular disruption or that vascular disruption may not play a major role in the pathogenesis of these two types of limb deficiencies.

Congenital constriction ring syndrome of the limbs: a prospective study of 16 cases

BACKGROUND

The congenital constriction ring syndrome is characterised by fibrous bands that encircle, strangle and even amputate parts of the foetus. It is a common condition amongst Ghanaian patients, but data on it is quite scanty.

MATERIALS AND METHODS

A prospective study of patients presenting at a plastic surgical clinic in Ghana with the characteristics of the congenital constriction ring syndrome was undertaken. The patients were examined clinically and the findings recorded. An x-ray and clinical photograph of the affected limbs was taken. Treatment required several staged operations. Surgical correction of the constriction ring was done by excision and Z-plasty to prevent or alleviate lymphoedema, separation of distally fused digits and skin grafting of defect.

RESULTS

Sixteen patients made up of 10 males and six females were seen. The age at presentation ranged from nine days to 12 years with a mean age of 14.6 months. Twenty-two limbs were affected, made up of four right upper limbs, six left upper limbs, seven right lower limbs and five left lower limbs. In the upper limb malformations involved 42 digits; in the lower limb malformations involved 33 toes, one foot and five legs. Four main types of lesions were found: constriction rings, intrauterine amputations, acrosyndactyly, and simple syndactyly.

CONCLUSION

Congenital constriction ring syndrome is of uncertain aetiology and could cause morbidity in the newborn. The syndrome and its complications are amenable to corrective surgery with good results. Early intervention is desirable for a successful outcome.

Ectrodactyly with fibular aplasia: a separate entity?

E/FA is the combination of ectrodactyly (split hand/foot malformation, SHFM) and fibular aplasia. It is a rare disorder considered to be inherited in an autosomal dominant fashion with reduced penetrance and variable expression. In order to determine recurrence risks for the two patients we describe, the literature on inheritance of E/FA was carefully reviewed. In our opinion, only two of the eight families previously reported as examples of familial E/FA may fit this judgment. Until mutation analysis of all SHFM genes is possible, the question remains whether these familial cases represent autosomal dominant E/FA, or an allelic variant of an SHFM subtype. Many sporadic patients with presumed E/FA may represent the fibular developmental field defect, which is a non-genetic entity with a low recurrence risk. We therefore suggest that the high recurrence risk associated with autosomal dominant inheritance should not be counselled in patients with E/FA unless their family shows the following characteristics: (1) at least one patient shows typical SHFM combined with fibular aplasia, (2) multiple limbs are affected, and (3) multiple family members are affected in at least two generations.

Surgical correction of congenital constriction band syndrome in children: Replacing Z-plasty with direct closure

Congenital constriction band syndrome is a sporadic condition that may also be present in association with other congenital anomalies. It has an incidence varying from one in 1200 to one in 15,000 live births. There is a significant predilection for the upper extremities and distal limbs. The two main objectives for the treatment of congenital constriction band syndrome are improvement of function and improvement of cosmetic appearance. Different surgical techniques, such as Z-plasty, have been described and used for decades; however, direct closure after the excision of the constricting band seems to be the simplest and most appropriate, allowing the fatty tissue to naturally reposition itself under the skin. This technique is used in a two-stage approach to avoid affecting distal circulation to the limb.

Amniotic band syndrome of the upper extremity: diagnosis and management

Amniotic band syndrome, a condition involving fetal entrapment in strands of amniotic tissue, causes an array of deletions and deformations. Band formation most frequently affects the distal segments, including the hand. Because of the heterogeneous nature of expression of this disease, treatment is individualized. Timing of repair and surgical planning are important in improving functional outcome. In the patient with distal edema and acrosyndactyly, early repair portends better prognosis. Improvements in prenatal diagnosis and fetoscopic surgical technique may eventually allow treatment of amniotic band syndrome in utero.

Clinical features and teratogenic mechanisms of congenital absence of digits

To have a better understanding of classification of congenital hand anomalies, clinical features and teratogenic mechanisms of congenital absence of digits including ulnar and radial deficiencies, cleft hand, symbrachydactyly and constriction band were reviewed. There seemed to be four different teratogenic mechanisms of congenital absence of digits. Ulnar and radial deficiencies have the same clinical features and the cause of these deficiencies is closely related to a deficit of mesenchymal cells in the limb-bud due to impairment before the formation of the limb-bud. Cleft hand, central polydactyly and osseous syndactyly were induced by the same treatment at the same developmental stage in rats. Roentgenograms of the clinical cases and skeletal changes of the anomalies in rats appear to demonstrate that cleft hand formation proceeds from osseous syndactylies and central polydactylies. The teratogenic mechanism of a cleft hand seemed to be failure of induction of digital rays in the hand plate. The sequence of anomalies from brachysyndactyly, or the atypical cleft hand, to the congenital amputation, can be regarded as equivalent to the category of transverse deficiency that is bony dysplasia of the hand. Congenital constriction ring syndrome appears after the formation of the digital rays.

Comparison of the amniotic band disruption complex with acardiac twins does not support its vascular origin

The amniotic band disruption complex (ABDC) has been attributed to vascular disruption by some authors, not by others. Acardiac twins (ATs), however, have been generally accepted as a prime example of vascular disruption. In this study a comparison was made of these two entities to determine if they were similar or not, and thus we attempted to resolve the controversy of the mechanisms in the ABDC. A female tendency (2:1) was found in the ABDC in contrast to the "normal" sex distribution (0.88:1) in the ATs (p < 0.001). Most types of malformations (66%) were mutually exclusive, notably those of the cranium/brain, abdominal wall, and most internal organs; 83% were more significantly related to one or other of the entities. The ABDC malformations tended to occur unilaterally, but in the ATs they occurred bilaterally (p < 0.0001); the former tended to involve external organs and the latter internal organs (p < 0.0001). With so many differences, the two entities are unlikely due to the same mechanism: the ABDC is more likely to be due to external disruption.

Evaluation of the cranial base in amnion rupture sequence involving the anterior neural tube: implications regarding recurrence risk

BACKGROUND

Amniotic bands can cause disruption of the cranial end of the developing fetus, leading in some cases to a neural tube closure defect. Although recurrence for unaffected parents of an affected child with a defect in which the neural tube closed normally but was subsequently disrupted by amniotic bands is negligible; for a primary defect in closure of the neural tube to which amnion has subsequently adhered, recurrence risk is 1.7%. In that primary defects of neural tube closure are characterized by typical abnormalities of the base of the skull, evaluation of the cranial base in such fetuses provides an approach for making a distinction between these 2 mechanisms. This distinction has implications regarding recurrence risk.

METHODS

The skull base of 2 fetuses with amnion rupture sequence involving the cranial end of the neural tube were compared to that of 1 fetus with anencephaly as well as that of a structurally normal fetus. The skulls were cleaned, fixed in 10% formalin, recleaned, and then exposed to 10% KOH solution. After washing and recleaning, the skulls were exposed to hydrogen peroxide for bleaching and photography.

RESULTS

Despite involvement of the anterior neural tube in both fetuses with amnion rupture sequence, in Case 3 the cranial base was normal while in Case 4 the cranial base was similar to that seen in anencephaly.

CONCLUSIONS

This technique provides a method for determining the developmental pathogenesis of anterior neural tube defects in cases of amnion rupture sequence. As such, it provides information that can be used to counsel parents of affected children with respect to recurrence risk.

Bone lengthening for congenital differences of the hands and digits in children

PURPOSE

We investigated the growth of bones after lengthening to evaluate the effectiveness and usefulness of bone lengthening in congenital hand deficiencies.

METHODS

Bone lengthening was performed to treat congenital hand deficiencies including hypoplastic thumb, hypoplasia of the small finger, cleft hand, metacarpal synostosis, brachymetacarpia, symbrachydactyly, and amniotic band syndrome. A total of 15 patients (1-13 years old) underwent lengthening of 23 bones. The average of distraction was 10 mm. The mean follow-up period was 59 months. The length of the bones at follow-up evaluation was measured and then compared with the length of the bones immediately after lengthening. The bone growth after lengthening, the percentage of growth after lengthening, and the growth rate were compared among diagnostic groups.

RESULTS

In the cases involving older patients the bone length changed little and the growth plates of these patients closed naturally soon after lengthening. In contrast, in the cases in which the patients were younger than 7 years old the lengthened bones grew continuously. The amount of bone growth was different for each disease in the younger patients. In patients with amniotic band syndrome the lengthened bones grew at the same rate as the bones in the hand. Other diagnoses such as symbrachydactyly had a different growth pattern in the hand.

CONCLUSIONS

We conclude that bone lengthening is a reliable method for the correction of congenital differences of the hand. The indications for this procedure must be determined while considering the relationship between the specific disease and subsequent bone growth.

Septo-optic dysplasia and amniotic bands: Further evidence for a vascular pathogenesis

Septo-optic dysplasia (SOD) is a heterogeneous disorder. While most cases represent an isolated defect, SOD has also been seen in association with mutations in single genes, as a part of multiple congenital anomaly syndromes and with exposure to various teratogens. We report a boy with features of SOD who also has limb defects suggestive of amniotic bands. This case, in addition to others in the literature, provides evidence for a vascular pathogenesis of SOD in some individuals. This hypothesis is also supported by the sporadic occurrence of SOD and its association with decreased maternal age, vascular teratogens, and neuropathologic findings suggestive of vascular insults.

Clinical and epidemiological studies of amniotic deformity, adhesion, and mutilation (ADAM) sequence in a South American (ECLAMC) population

Amniotic deformity, adhesion, and mutilation (ADAM) sequence is a heterogeneous condition, with a broad spectrum of anomalies, where intrinsic causes, as defect of germ plasm, vascular disruption, and disturbance of threshold boundaries of morphogens during early gastrulation, alternate with extrinsic causes as amniotic band rupture to explain the condition. This study aimed to identify which phenotypes could be considered as ADAM sequence, determine the prevalence rate, and disclose risk factors for this sequence. We identified 270 cases defined as having some skin evidence of constriction band, plus those having limb defects suggestive of ADAM sequence, among 3,020,896 live and stillborns in the years 1982 to 1998 in ECLAMC (Latin American Collaborative Study of Congenital Malformations). Half of the cases presented mutilation (reduction), and deformity (ring constriction) affecting distal parts of fingers or toes bilaterally, without associated defects. Acrania, cephalocele, typical or atypical facial clefts, eyelid coloboma, and celosomia were also observed being significantly associated with the skin lesion. One affected infant in every 11,200 births, was found with stable trends during the last 17 years. There was an excess of cases in populations living at high altitude, stillborns, and neonatal infant dead. Among ADAM cases there was an excess of mothers with a prenatal history of febrile acute illness, medication drug use, or vaginal bleeding during the first trimester of pregnancy. Higher than expected frequencies of first-born child, premature birth, low birth weight for gestational length, and non-cephalic fetal presentation were also found. The observed geographic difference in birth prevalence could be a useful indication to study specific genetic and environmental candidate factors to ADAM susceptibility.

Case of constriction band syndrome with annular epidermal cyst

Both intrinsic and extrinsic theories have been proposed to explain the etiology of congenital constriction band syndrome. The authors report a case of construction band syndrome in which an epidermal cyst was involved. It was located along the annular band of the affected finger and formed a complete ring. This case suggests that the epidermal cyst was produced by circumferential compression, advocating the extrinsic theory for this syndrome.

Body stalk defects, body wall defects, amniotic bands with and without body wall defects, and gastroschisis: comparative epidemiology

The presence of body wall defects with "evisceration" of thoracic and/or abdominal organs associated with other congenital anomalies, with or without limb deficiencies, is considered to be the body wall complex (BWC). The BWC is different from gastroschisis, which is usually a small body wall defect lateral to the umbilical cord that is not covered by any membrane and, in most of the cases, is an isolated defect. For the present analysis we separated the BWC group into three subgroups. One group was that of body stalk anomalies characterized by severe defects of the abdominal wall with absence of, or very small, umbilical cord, or this is continuing with the placenta. The second group was made up of those infants with body wall defects without amniotic bands, and the third group was of those children with body wall defects produced by amniotic bands. We considered two additional groups in the analysis, one was of infants with gastroschisis and the other those infants with amniotic bands without body wall affectation. We also included the control group (nonmalformed infants) for comparisons. From the results of our epidemiological study, we can conclude that amniotic bands with body wall affectation and amniotic bands without body wall defects are two different entities. The results also suggest that the characteristics of infants with amniotic bands with body wall defects are more similar to the group of infants with body stalk anomalies. This may indicate that the former group is produced during the very early gestation.

Amniotic band syndrome

Amniotic band syndrome is an uncommon, congenital fetal abnormality with multiple disfiguring and disabling manifestations. A wide spectrum of clinical deformities are encountered and range from simple ring constrictions to major craniofacial and visceral defects. Lower extremity limb malformations are extremely common and consist of asymmetric digital ring constrictions, distal atrophy, congenital intrauterine amputations, acrosyndactyly, lymphedema and clubfoot. Although debated, early amnion rupture with subsequent entanglement of fetal parts (mostly limbs and appendages) by amniotic strands is the primary theory of pathogenesis. The sporadic nature of this congenital anomaly is discussed, as well as a case study involving the surgical correction of an associated rigid clubfoot deformity.

Epidemiological characteristics of amniotic band sequence (ABS) and body wall complex (BWC): are they two different entities?

In 1965, Torpin [1965; Am J Obstet Gynecol 91:65-75] concluded that fetal constrictions and amputations were related to amniotic membrane rupture. Since then, this view was accepted widely, although different terms were used due to the variation in the types of associated anomalies. I consider that for those cases without body wall defects, the most appropriate term is amniotic band sequence (ABS), since amnion rupture could initiate a cascade of abnormalities (consequences) leading to the final structural defects. Here I present a clinical and epidemiological analysis of a series of consecutive infants with ABS, comparing their characteristics with those of infants with body wall complex (BWC). The results of this analysis suggest that ABS, from an epidemiological standpoint, is an entity different from BWC, and that amniotic bands in cases of BWC may be considered different from amniotic bands in cases without body wall defects. The former are probably produced earlier in the development than the latter.

Congenital anomalies of the hand. The Asian perspective

To have a better understanding of teratogenic mechanisms of congenital absence of digits, ulnar and radial deficiencies, cleft hand, and symbrachydactyly were analyzed in clinical cases. The same anomalies were induced in rat fetuses by busulfan, and their characteristics were investigated. The formation process of longitudinal deficiency also was observed histologically. There seemed to be 4 teratogenic mechanisms of congenital absence of digits. Ulnar and radial deficiencies have the same clinical features, and the cause of these deficiencies is related closely to a deficit of mesenchymal cells in the limb bud caused by the impairment before the formation of the limb bud. Cleft hand, central polydactyly, and osseous syndactyly were induced by the same treatment at the same developmental stage in rats. Cleft hand formation process from osseous syndactylies and central polydactylies was supposed. The teratogenic mechanism of cleft hand seemed to be failure of induction of digital rays in the hand plate. The sequence of anomalies from brachysyndactyly, or the atypical cleft hand, to the transverse deficiency can be regarded as equivalent to the category of bony dysplasia of the hand. Congenital constriction ring syndrome does appear after the formation of the digital rays.

Clubfeet in congenital annular constricting bands

Thirty-five children who had congenital annular constricting bands (Streeter's dysplasia) with associated clubfeet seen by the author from September 1989 to March 1992 were reviewed with respect to quality of the clubfeet,the relationship of the bands with the clubfeet, possible prenatal factors, and treatment results. It was noted that all the clubfeet were rigid even if there were no constricting bands in the leg with the clubfoot. The clubfeet responded poorly to casting (6% success) and 77% required surgical correction. Z-plasties of deep bands were done before clubfoot correction. There was a high incidence of abnormal pregnancies with attempts at abortion in 66% of the cases, suggesting intrauterine insult early in the pregnancy as a factor causing both the clubfeet and the Streeter's dysplasia.