Caudal duplication

Last updated
Caudal duplication
Other namesSplit notochord syndrome [1]

Caudal duplication, (or caudal duplication syndrome) is a rare congenital disorder in which various structures of the caudal region, embryonic cloaca, and neural tube exhibit a spectrum of abnormalities such as duplication and malformations. [2] The exact causes of the condition is unknown, [2] though there are several theories implicating abnormal embryological development as a cause for the condition. [3] Diagnosis is often made during prenatal development of the second trimester through anomaly scans or immediately after birth. [4] However, rare cases of adulthood diagnosis has also been observed. Treatment is often required to correct such abnormalities according to the range of symptoms present, [4] whilst treatment options vary from conservative expectant management to resection of caudal tissue to restore normal function or appearance. [5] As a rare congenital disorder, the prevalence at birth is less than 1 per 100,000 [3] with less than 100 cases reported worldwide. [6]

Contents

The term "caudal duplication syndrome" has been coined since 1993 [2] to describe caudal abnormalities and conditions. However, there has been recent debate into the appropriateness of the term being "caudal split syndrome" instead of caudal duplication due to the "splitting" nature of the abnormalities, rather than "duplication". [5]

Signs and symptoms

The condition’s symptoms vary greatly due to the diverse spectrum of gastrointestinal (GI), urogenital (genitourinary, GU), spinal, and limb anomalies possible. [7] Common forms include anorectal malformation and duplication of the external genitalia, [7] while less common forms may include incomplete duplication of the lower spine and spinal cord, (diastematomyelia) [8] and partial fusion to complete duplication of the uterus, vagina, colon, and bladder. [9]

Malformations of the spine are indicated to cause varying levels of neurological impairment. [8] Although the level of neurological impairment is dependent upon the severity and type of spinal abnormality, most reported cases of spinal cord duplication exhibit severe neurological impairment, [8] though cases of mild or absent neurological impairment has also been observed. [8]

Though patients often present a diverse variety of symptoms, a case was observed in which a female adult with duplication of the colon, rectum, anus, urinary bladder, urethra, uterus, cervix, vagina, and external genitalia exhibited no detrimental effects. [4] This suggests that rarely seen cases of complete duplication of the urogenital and gastrointestinal tract are often asymptomatic. [10]

As patients often present a multitude of differing symptoms within the caudal region, each patient exhibits a unique, characterised symptom which may or may not be cosmetically or physiologically detrimental to the individual. [2]

Summary of Caudal Duplication Anomalies
Classification [2] Anomalies and salient clinical features [2]
Gastrointestinal tract anomalies
Genitourinary tract anomalies
Spinal anomalies (includes lower limb anomalies)

Causes

The exact cause of the condition is unknown. [2] Although various theories indicate incomplete separation of monozygotic twins as an etiological factor, [3] abnormal adherence between the ectoderm and endoderm during gastrulation, [7] polytopic primary developmental field defects, [11] somatic and germ line mutations in developmental genes, [3] and damage to the caudal cell mass and posterior gut have also been linked to cause structural anomalies in the caudal region. [7]

It is speculated that the condition is related to the HOX gene, [3] namely HOX10 and HOX11. Normally coding for the mammalian appendicular and axial skeleton, misexpression of the genetic factors could lead to abnormal proliferation of the caudal mesenchyme. [3]

Embryology is suggested to have an intimate association with the development of caudal duplication syndrome. [2] At day 15 after fertilisation, the notochord grows from the primitive knot, in which it invaginates and forms the notochord canal within. [2] Progressively, on day 20, the ventral wall of the notochord dissolves, while communications are formed between the amniotic and yolk sac. [2] One such connection is the Kovalevsky’s canal. From the 23rd to 25th day of gestation, the spinal cord develops except for its distal-most aspect where the notochord and neural tube are joined to form the caudal cell mass. [2] The canal of Kovalevsky crosses the caudal cell mass, while endoderm located anteriorly to the cell mass develops into the hindgut, various insults towards the cell mass and hindgut during the stage of development may lead to the development of caudal anomalies, one of which is caudal duplication syndrome. [2]

The incomplete regression of Kovalevsky’s canal may also lead to formations of fibrous bands joining the hindgut to the spinal canal, [5] possibly leading to the onset of diastemetaomyelia. [4] These bands may divide the notochord, developing into duplications of the lower spine and spinal cord, the adjacent mesoderm is also divided, resulting in duplicates of GI and GU tracts. [4] Subsequently, the duplications can also lead to the presence of a range of anomalies including dorsal enteric fistulas, enteric cysts, spina bifida, malformed or duplicated colon, bladder, sacrum, and lower spinal cord. [2] [12]

Moreover, a midline pelvic mass defect during gestation could be an obstacle to caudal migration of paramesonephric structures (Müllerian duct), which could lead to duplication of the genital tract. [2] Whilst failures of migration or fusion of those structures is one of the more prevalent embryological theories for duplication of lower genitourinary organs such as the bladder. [2] Intestinal duplications extending into the rectum or anus is often rare. [2] [6] However, if the caudal cell mass is divided early, duplications of the distal bowel may still occur. [2]

In gastrointestinal abnormalities, a mechanism known as “caudal twinning” [3] is proposed in which during the 23rd to 25th day of gestation, the intestinal tract is filled by rapid proliferation of endothelial cells, as the gut increases in size, vacuoles appear within the cell masses to constitute a single lumen. [2] [4] However, in abnormal cases where a vacuole is pinched off, a second lumen is created. [4] The second lumen is then proposed to magnify in size in proportion to the growth of the colon, effectively duplicating all caudal structures distal from the point of separation. [2] [10]

Diagnosis

The condition can often be seen as malformations that can be diagnosed by a prenatal anomaly scan in the second trimester, while progressively detailed examinations can be conducted after the first day of life of the baby. [3] If an abnormality is detected early on, psychological and surgical preparation may be required to resort to a cesarean section to prevent obstructed labour, in which medical paediatric and surgical care soon follows after delivery. [13] [14] [15]

Diagnosis during adulthood is extremely rare [2] in cases where abnormalities are asymptomatic or are not visible upon physical inspection upon prenatal or birth inspections. [6] Similarly to paediatric and prenatal diagnosis, an adulthood diagnosis can be made through various imaging modalities [4] such as computed tomography (CT) scans to explicitly define the range of symptoms present in caudal duplication. [13]

Classification

Dipygus deformity is a severe and extreme type of caudal duplication that occurs at the caudal end of the body axis, where it duplicates completely. [16]

Treatment

The rare, complex syndrome includes a wide spectrum of malformations ranging from partial or isolated to complete duplication of caudal organs in GI, GU, and neural systems. [13] The syndrome may cause functional impairments such as an imperforate anus and hernia which may lead to death due to shock and organ failure and require prompt surgical intervention, [17] but most presented symptoms are not life-threatening and duplicated organs are in fact functional in many cases. [2] [6] For instance, patients with genital duplication are mostly expected to have normal menstruation, sexual intercourse, and even pregnancy, [18] although their self-esteem and quality of life may be influenced. [5] Since the clinical presentation of each patient and its complexity vary greatly, the management which usually includes surgery are carefully planned and individualised based on the extent of duplication and functionality of the involved organs. [4]

An extensive medical work-up is required primarily before prognosis to understand the anatomy of patients and to decide appropriate treatment. Imaging modalities such as echocardiography, conventional X-ray, magnetic resonance imaging (MRI), ultrasonography, barium enema, computed tomography (CT) scan, and voiding cystourethrography (VCU) can be used to examine anomalies in detail. [3] [4] [13] Exploratory laparotomy can also be conducted when needed. [7] In most cases, surgical approach is utilised to excise or fuse the duplicated organs; [3] [7] [19] however, surgical intervention is not a compulsory procedure for patients that do not exhibit functional deterioration and symptoms. [4] Based on the work-up results, a multidisciplinary team consisting of a (paediatric) surgeon, a urologist, and a neurosurgeon plans individualised, staged correction. [20]

If a prenatal or after birth diagnosis is made, medical paediatric and surgery care are organised soon after delivery. [15] Adults with the syndrome, however, usually do not require surgical treatment unless accompanied by symptoms or psychological issues. [4] [6] Reconstructive surgeries are performed to resolve the issue of functional impairments such as obstruction of colon, anatomic anomalies that hinder movement or cause infertility, and to improve cosmetic appearances in the case of genital duplication. [4]

Gastrointestinal tract

Treatments for colonic duplication varies from conservative management for asymptomatic cases to excision of duplicated colon to avoid potential issues such as colon structure and obstruction. [4] [7] Resection is possible when each duplicated colon has a complete blood supply. If the duplicated colons share a wall, a septotomy can be performed to create a small hole to connect two colons. [4] [7] In cases where rectum is also duplicated, either the rectums should be converted into one reservoir through septotomy followed by anorectoplasty or the duplicated colon and rectum should be removed and colostomies should be constructed. [4] For patients with poor prognosis for bowel control, a Malone procedure can be utilised during the colostomy. [4] Alternatively, in cases of renal duplication, the Mitrofanoff procedure is performed instead. [4]

Genitourinary tract

Duplication of genital tract that does not involve functional impairment does not require surgical intervention; however, plastic surgery can be carried out to improve patients’ self-esteem and social status. [19] For duplication of female genital tract, the septum between duplicated organs such as vagina, cervix, and vulva are resected to combine two duplicated organs into one or one duplicated organ could be detached and excised. [19] For male patients, one duplicated genitalia can be removed, and duplicated scrotum and testis can be either combined or excised. [15] The external genitalia of both male and female can be reconstructed by midline apposition of tissues. [19] For duplication of urinary tract, bladders can be combined to form a single larger bladder without altering the duplicated ureters. [19]

Spinal and lower limb tract

In cases of spine duplication, prophylactic surgery can be done to remove one duplicated spine, although it depends on the severity of duplication. [21] In cases of malformation of the neural cord such as myelomeningocele and tethered cord which accompanies severe symptoms, preserving neurological function is the utmost importance by closing myelomeningocele and detethering the neural cord. [4] This is a highly complex procedure that requires extreme caution not to injure the rectum in which case can cause a cerebrospinal fluid infection. [4] For duplication of lower limb which not only hinders patients’ gait but also is highly visible and may affect patients’ self-esteem, excision of the supernumerary, non-functional pair of limb is often carried out. [15]

Due to the spectrum of symptoms present within caudal duplication, there is no uniform surgical treatment in relieving symptoms. [20] The type and severity of surgical intervention is often dependent upon the type and complexity of symptoms presented. [20] Thus, the primary goal of surgical treatment for the syndrome is to relieve symptoms, not to restore normal anatomy, and hence, potentially life-threatening malformations are addressed first and often followed by other anatomic or aesthetic reconstructions in later stages. [4] [6] After the medical treatment, the patients are periodically monitored. [19] [15]

Epidemiology

Caudal duplication syndrome is a rare condition with only less than 100 patients in literature worldwide as of 2014 with only 2 patients diagnosed in adulthood. [6] The prevalence of the syndrome is less than one per 100,000 births. [5] The sex ratio of male to female patients is about 1:2, with no familial or racial predisposition being found. [20]

History

The first systematic review for caudal duplication symptoms was done and the term "caudal duplication syndrome" was first proposed in 1993. [2] The term was coined to describe rare anomalies associated with complete or partial duplication of caudal structures resulted from insults during embryogenesis to distinguish symptoms of spinal duplication syndrome which only involves spinal duplicity, only when there is associated complete or partial duplicity of vascular structures and/or organs such as bladder and distal gastrointestinal tract the term caudal duplication syndrome can be used. [12]

However, recently in 2013, it was suggested that “duplication” is a misnomer based on an analysis of two cases and literature review in which researchers found “hemi” organs was “split” not duplicated, proposing caudal “split” syndrome may be a more appropriate title. [5]

Related Research Articles

<span class="mw-page-title-main">Arteriovenous malformation</span> Vascular anomaly

An arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system. Usually congenital, this vascular anomaly is widely known because of its occurrence in the central nervous system, but can appear anywhere in the body. The symptoms of AVMs can range from none at all to intense pain or bleeding, and they can lead to other serious medical problems.

<span class="mw-page-title-main">Syringomyelia</span> Disorder in which a cyst forms in the spinal cord

Syringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. Often, syringomyelia is used as a generic term before an etiology is determined. This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in loss of feeling, paralysis, weakness, and stiffness in the back, shoulders, and extremities. Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. It may also lead to a cape-like bilateral loss of pain and temperature sensation along the upper chest and arms. The combination of symptoms varies from one patient to another depending on the location of the syrinx within the spinal cord, as well as its extent.

<span class="mw-page-title-main">Chiari malformation</span> Medical condition

Chiari malformation (CM) is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum.

<span class="mw-page-title-main">Autonomic neuropathy</span> Medical condition

Autonomic neuropathy is a form of polyneuropathy that affects the non-voluntary, non-sensory nervous system, affecting mostly the internal organs such as the bladder muscles, the cardiovascular system, the digestive tract, and the genital organs. These nerves are not under a person's conscious control and function automatically. Autonomic nerve fibers form large collections in the thorax, abdomen, and pelvis outside the spinal cord. They have connections with the spinal cord and ultimately the brain, however. Most commonly autonomic neuropathy is seen in persons with long-standing diabetes mellitus type 1 and 2. In most—but not all—cases, autonomic neuropathy occurs alongside other forms of neuropathy, such as sensory neuropathy.

In humans and other mammals, the caudal cell mass is the aggregate of undifferentiated cells at the caudal end on the spine. The caudal end of the spinal cord first begins to form after primary neurulation has taken place, indicating that it develops after the cranial portion of the spinal cord has developed. Following neurulation, the caudal tail begins to form a neurocele as it develops a hollow core. After this, secondary neurulation occurs in which the medullary cord begins to form and is filled with many cavities that ultimately form the lumen. The cavities formed from the initial and secondary neurulation combine to form one uninterrupted cavity. There is still speculation on the formation of the caudal cell mass in humans with arguments being made for it arising from many cavities or the continuing growth of the neurocele from the initial neurulation. The caudal cell mass will ultimately differentiate and form into many sacral structures such various nerve endings and the conus medullaris.

<span class="mw-page-title-main">Omphalocele</span> Rare abdominal wall defect in which internal organs remain outside of the abdomen in a sac

An omphalocele or omphalocoele, also known as an exomphalos, is a rare abdominal wall defect. Beginning at the 6th week of development, rapid elongation of the gut and increased liver size reduces intra abdominal space, which pushes intestinal loops out of the abdominal cavity. Around 10th week, the intestine returns to the abdominal cavity and the process is completed by the 12th week. Persistence of intestine or the presence of other abdominal viscera in the umbilical cord results in an omphalocele.

<span class="mw-page-title-main">Cauda equina syndrome</span> Nerve damage at the end of the spinal cord

Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.

<span class="mw-page-title-main">Uterine malformation</span> Medical condition

A uterine malformation is a type of female genital malformation resulting from an abnormal development of the Müllerian duct(s) during embryogenesis. Symptoms range from amenorrhea, infertility, recurrent pregnancy loss, and pain, to normal functioning depending on the nature of the defect.

<span class="mw-page-title-main">Imperforate anus</span> Birth defect of malformed rectum

An imperforate anus or anorectal malformations (ARMs) are birth defects in which the rectum is malformed. ARMs are a spectrum of different congenital anomalies which vary from fairly minor lesions to complex anomalies. The cause of ARMs is unknown; the genetic basis of these anomalies is very complex because of their anatomical variability. In 8% of patients, genetic factors are clearly associated with ARMs. Anorectal malformation in Currarino syndrome represents the only association for which the gene HLXB9 has been identified.

Vaginal atresia is a condition in which the vagina is abnormally closed or absent. The main causes can either be complete vaginal hypoplasia, or a vaginal obstruction, often caused by an imperforate hymen or, less commonly, a transverse vaginal septum. It results in uterovaginal outflow tract obstruction. This condition does not usually occur by itself within an individual, but coupled with other developmental disorders within the female. The disorders that are usually coupled with a female who has vaginal atresia are Mayer-Rokitansky-Küster-Hauser syndrome, Bardet-Biedl syndrome, or Fraser syndrome. One out of every 5,000 women have this abnormality.

Tethered cord syndrome (TCS) refers to a group of neurological disorders that relate to malformations of the spinal cord. Various forms include tight filum terminale, lipomeningomyelocele, split cord malformations (diastematomyelia), occult, dermal sinus tracts, and dermoids. All forms involve the pulling of the spinal cord at the base of the spinal canal, literally a tethered cord. The spinal cord normally hangs loose in the canal, free to move up and down with growth, and with bending and stretching. A tethered cord, however, is held taut at the end or at some point in the spinal canal. In children, a tethered cord can force the spinal cord to stretch as they grow. In adults the spinal cord stretches in the course of normal activity, usually leading to progressive spinal cord damage if untreated. TCS is often associated with the closure of a spina bifida. It can be congenital, such as in tight filum terminale, or the result of injury later in life.

<span class="mw-page-title-main">Neurogenic bladder dysfunction</span> Medical condition

Neurogenic bladder dysfunction, often called by the shortened term neurogenic bladder, refers to urinary bladder problems due to disease or injury of the central nervous system or peripheral nerves involved in the control of urination. There are multiple types of neurogenic bladder depending on the underlying cause and the symptoms. Symptoms include overactive bladder, urinary urgency, frequency, incontinence or difficulty passing urine. A range of diseases or conditions can cause neurogenic bladder including spinal cord injury, multiple sclerosis, stroke, brain injury, spina bifida, peripheral nerve damage, Parkinson's disease, multiple system atrophy or other neurodegenerative diseases. Neurogenic bladder can be diagnosed through a history and physical as well as imaging and more specialized testing. In addition to symptomatic treatment, treatment depends on the nature of the underlying disease and can be managed with behavioral changes, medications, surgeries, or other procedures. The symptoms of neurogenic bladder, especially incontinence, can severely degrade a person's quality of life.

<span class="mw-page-title-main">Diastematomyelia</span> Medical condition

Diastematomyelia is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra in the longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous, cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as diplomyelia, which is true duplication of the spinal cord.

<span class="mw-page-title-main">Diphallia</span> Genital medical condition

Diphallia, penile duplication (PD), diphallic terata, or diphallasparatus is an extremely rare developmental abnormality in which a male is born with two penises. The first reported case was by Johannes Jacob Wecker in 1609. Its occurrence is 1 in 5.5 million boys in the United States.

Malpuech facial clefting syndrome, also called Malpuech syndrome or Gypsy type facial clefting syndrome, is a rare congenital syndrome. It is characterized by facial clefting, a caudal appendage, growth deficiency, intellectual and developmental disability, and abnormalities of the renal system (kidneys) and the male genitalia. Abnormalities of the heart, and other skeletal malformations may also be present. The syndrome was initially described by Georges Malpuech and associates in 1983. It is thought to be genetically related to Juberg-Hayward syndrome. Malpuech syndrome has also been considered as part of a spectrum of congenital genetic disorders associated with similar facial, urogenital and skeletal anomalies. Termed "3MC syndrome", this proposed spectrum includes Malpuech, Michels and Mingarelli-Carnevale (OSA) syndromes. Mutations in the COLLEC11 and MASP1 genes are believed to be a cause of these syndromes. The incidence of Malpuech syndrome is unknown. The pattern of inheritance is autosomal recessive, which means a defective (mutated) gene associated with the syndrome is located on an autosome, and the syndrome occurs when two copies of this defective gene are inherited.

Obstructed defecation syndrome is a major cause of functional constipation, of which it is considered a subtype. It is characterized by difficult and/or incomplete emptying of the rectum with or without an actual reduction in the number of bowel movements per week. Normal definitions of functional constipation include infrequent bowel movements and hard stools. In contrast, ODS may occur with frequent bowel movements and even with soft stools, and the colonic transit time may be normal, but delayed in the rectum and sigmoid colon.

Dyssynergia is any disturbance of muscular coordination, resulting in uncoordinated and abrupt movements. This is also an aspect of ataxia. It is typical for dyssynergic patients to split a movement into several smaller movements. Types of dyssynergia include Ramsay Hunt syndrome type 1, bladder sphincter dyssynergia, and anal sphincter dyssynergia.

<span class="mw-page-title-main">CLOVES syndrome</span> Medical condition

CLOVES syndrome is a rare overgrowth syndrome with complex vascular anomalies. CLOVES syndrome affects people with various symptoms, ranging from mild fatty soft-tissue tumors to vascular malformations encompassing the spine or internal organs.

<span class="mw-page-title-main">Vaginal anomalies</span> Congenital defect; abnormal or absent vagina

Vaginal anomalies are abnormal structures that are formed during the prenatal development of the female reproductive system and are rare congenital defects that result in an abnormal or absent vagina.

A lipomyelomeningocele is a type of closed neural tube defect that affects around 3 to 6 babies out of 100,000 births. It is an example of a spinal lipoma, which is a collection of adipose tissue, or fat, that is located at or around the spinal cord. Essentially, it is a tumor of fat located on the spinal cord. A lipomyelomeningocele defect is present at birth and can present with physical defect of the spine and back, and it can also cause various neurological symptoms such as weakness and bladder and bowel incontinence. The general treatment for this spinal defect is surgical detachment of the lipoma from the spine.

References

  1. ↑ RESERVED, INSERM US14-- ALL RIGHTS. "Orphanet: Caudal duplication". www.orpha.net. Retrieved 27 October 2019.{{cite web}}: CS1 maint: numeric names: authors list (link)
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Dominguez R, Rott J, Castillo M, Pittaluga RR, Corriere JN (October 1993). "Caudal Duplication Syndrome". Archives of Pediatrics & Adolescent Medicine. 147 (10): 1048–52. doi:10.1001/archpedi.1993.02160340034009. PMID   8213674. S2CID   19679795.
  3. 1 2 3 4 5 6 7 8 9 10 Sur A, Sardar SK, Paria A (April 2013). "Caudal duplication syndrome". Journal of Clinical Neonatology. 2 (2): 101–2. doi: 10.4103/2249-4847.116412 . PMC   3775131 . PMID   24049755.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Samuk I, Levitt M, Dlugy E, Kravarusic D, Ben-Meir D, Rajz G, et al. (December 2016). "Caudal Duplication Syndrome: the Vital Role of a Multidisciplinary Approach and Staged Correction". European Journal of Pediatric Surgery Reports. 4 (1): 001–005. doi:10.1055/s-0035-1570370. PMC   5177553 . PMID   28018799.
  5. 1 2 3 4 5 6 Molinaro F, Cerchia E, Bulotta AL, Angotti R, Di Maggio G, Bianchi A, Messina M (October 2013). "Caudal 'duplication' or 'split' syndrome: Is there a misnomer?". Journal of Pediatric Surgery Case Reports. 1 (10): 351–356. doi: 10.1016/j.epsc.2013.09.007 .
  6. 1 2 3 4 5 6 7 Goil P, Bannerjee A (2015-04-10). "A Rare Presentation of Caudal Duplication Syndrome in an Adult with No Functional Impairment". Journal of Case Reports. 4 (2): 324–327. doi: 10.17659/01.2014.0081 .
  7. 1 2 3 4 5 6 7 8 Swaika S, Basu S, Bhadra RC, Sarkar R, Maitra SK (June 2013). "Caudal duplication syndrome-report of a case and review of literature". The Indian Journal of Surgery. 75 (Suppl 1): 484–7. doi:10.1007/s12262-013-0838-z. PMC   3693374 . PMID   24426655.
  8. 1 2 3 4 5 Taneja AK, Zaffani G, Amato-Filho AC, Queiroz L, Zanardi V, Menezes-Netto JR (September 2009). "Caudal duplication syndrome". Arquivos de Neuro-Psiquiatria. 67 (3A): 695–6. doi: 10.1590/S0004-282X2009000400023 . PMID   19722052.
  9. ↑ Online Mendelian Inheritance in Man (OMIM): Caudal Duplication Anomaly - 607864
  10. 1 2 Shah KR, Joshi A (March 2006). "Complete genitourinary and colonic duplication: a rare presentation in an adult patient". Journal of Ultrasound in Medicine. 25 (3): 407–11. doi:10.7863/jum.2006.25.3.407. PMID   16495506.
  11. ↑ Kroes HY, Takahashi M, Zijlstra RJ, Baert JA, Kooi KA, Hofstra RM, van Essen AJ (November 2002). "Two cases of the caudal duplication anomaly including a discordant monozygotic twin". American Journal of Medical Genetics. 112 (4): 390–3. doi:10.1002/ajmg.10594. PMID   12376942.
  12. 1 2 Pang D, Dias MS, Ahab-Barmada M (September 1992). "Split cord malformation: Part I: A unified theory of embryogenesis for double spinal cord malformations". Neurosurgery. 31 (3): 451–80. doi: 10.1227/00006123-199209000-00010 . PMID   1407428.
  13. 1 2 3 4 Hu T, Browning T, Bishop K (March 2016). "Caudal duplication syndrome: imaging evaluation of a rare entity in an adult patient". Radiology Case Reports. 11 (1): 11–5. doi:10.1016/j.radcr.2015.12.001. PMC   4769617 . PMID   26973727.
  14. ↑ Hindryckx A, De Catte L (2011). "Prenatal diagnosis of congenital renal and urinary tract malformations". Facts, Views & Vision in ObGyn. 3 (3): 165–74. PMC   3991456 . PMID   24753862.
  15. 1 2 3 4 5 Bandré E, Wandaogo A, Kabre SM, Ouedraogo I, Napon M (Nov 2015). "Challenges in the management of a rare case of caudal duplication syndrome in a poor resource setting". Journal of Pediatric Surgery Case Reports. 3 (11): 508–511. doi: 10.1016/j.epsc.2015.10.003 .
  16. ↑ Samujh, Ram; Lyngdoh, ToijamSoni; Mansoor, Khizer; Al Kasim, Fawaz; Al-Mustafa, AbdulazizA; Al Alayet, YasenFayez (2014). "An extremely rare case of classic complete caudal duplication: Dipygus". Journal of Indian Association of Pediatric Surgeons. 19 (3). Medknow: 169. doi: 10.4103/0971-9261.136478 . ISSN   0971-9261. PMC   4155636 .
  17. ↑ Acer T, Ötgün İ, Sağnak Akıllı M, Gürbüz EE, Güney LH, Hiçsönmez A (May 2013). "A newborn with caudal duplication and duplex imperforate anus". Journal of Pediatric Surgery. 48 (5): E37-43. doi:10.1016/j.jpedsurg.2013.03.068. PMID   23701807.
  18. ↑ Lin PC, Bhatnagar KP, Nettleton GS, Nakajima ST (November 2002). "Female genital anomalies affecting reproduction". Fertility and Sterility. 78 (5): 899–915. doi: 10.1016/S0015-0282(02)03368-X . PMID   12413972.
  19. 1 2 3 4 5 6 Molinaro F, Cerchia E, Bulotta AL, Angotti R, Di Maggio G, Bianchi A, Messina M (Oct 2013). "Caudal 'duplication' or 'split' syndrome: Is there a misnomer?". Journal of Pediatric Surgery Case Reports. 1 (10): 351–356. doi: 10.1016/j.epsc.2013.09.007 .
  20. 1 2 3 4 Ramzan M, Ahmed S, Ali S (January 2014). "Caudal duplication syndrome" (PDF). Journal of the College of Physicians and Surgeons--Pakistan. 24 (1): 64–6. PMID   24411548.
  21. ↑ Cebesoy O, Mete A, Karsli B (Feb 2009). "Complete lumbar spine duplication in a neurologically intact man". The Journal of Spinal Cord Medicine. 32 (1): 99–102. doi:10.1080/10790268.2009.11760759. PMC   2647508 . PMID   19264056.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.