Separation of brachio-thoraco-omphalo-ischiopagus bipus conjoined twins

Journal of Pediatric Surgery APRIL 1994

VOL 29, NO 4

Separation

of Brachio-Thoraco-Omphalo-Ischiopagus Conjoined Twins By L. Spitz, M.D. Stringer,

E.M. Kiely,

Bipus

P.G. Ransley, and P. Smith

London, England l Separation of 3-year-old brachio-thoraco-omphalo-ishiopagus bipus conjoined twin girls is reported. Detailed preoperative assessment and a multidisciplinary approach were essential prerequistes to surgery. The difficulties of managing the extensive body wall defect resulting from separation are discussed. Despite the use of subcutaneous and intraperitoneal tissue expanders, a large area of prosthetic material was required to reconstruct the abdominal wall. Skin cover was achieved using a combination of meshed allogeneic skin, homograft split skin, and autologous cultured keratinocytes. One twin died in the early postoperative period, but the other has recovered well and is awaiting further rehabilitative treatment. Copyright 0 1994 by W.8. Saunders Company

INDEX WORDS:

Conjoined twins; tissue expansion.

T

HE MANAGEMENT of conjoined twins provides many dilemmas for the pediatric surgeon. This is particularly true if the twins are extensively joined and yet capable of independent existence. We report the separation of 3-year-old brachio-thoracoomphalo-ischiopagus bipus conjoined twins and focus on the difficulties of obtaining body wall closure in the presence of such an extensive union. CASE REPORT Conjoined twin girls were born in 1988, to a 2%year-old mother (gravida 4, para 3) after an uncomplicated pregnancy. They were diagnosed antenatally in early pregnancy and delivered by elective cesarean section at 38 weeks’ gestation, weighing 4.5 kg. There were no major neonatal problems, and after detailed radiological investigations they were discharged home, at 4 months of age. They were readmitted at 2% years of age when twin 2 required treatment for pneumonia. The twins were referred to the Hospital for Sick Children, London, in January 1992 for assessment of possible separation. The twins were healthy and intelligent; they were joined from the forearms and shoulder to the pelvis (brachiothoraco-omphalo-ischiopagus bipus) and faced each other obliquely at approximately 120” (Fig 1). Their conjoined circumference measured 78 cm. They had two independent, normal lower limbs, two normal upper limbs, and independently functioning but conjoined upper limbs. Twin 2 had a marked scoliosis. The perineum had the appearance of a single female, and the rectum was distended, with soft feces.

JournalofPediatric Surgery, Vol29, No 4 (April), 1994: pp 477-481

MATERIALS

AND METHODS

Investigations Routine investigations were supplemented by detailed echocardiography, gastrointestinal contrast studies, total body magnetic resonance imaging, cystoscopy with retrograde studies, radioisotope scans (DMSA and technetium 99m-HIDA), electromyography (EMG) of the pelvic floor musculature, and visceral angiography. Orthopedic, physiotherapy, and psychological assessments were obtained. The results are summarized in Table 1, and Fig 2 shows the extent and complexity of the anatomic union.

Preoperative Preparation The investigations showed no anatomic bar to separation, and attention was then focused on the problems of abdominal wall and skin cover postseparation. Two l,OOO-mLSilastic tissue expanders (Dow Corning Corp, Midland, MI) were inserted into the peritoneal cavity via an upper midline abdominal incision.’ Two smaller expanders were positioned subcutaneously in the midline over the anterior and posterior chest wall. During the same operation, the fused forearms were divided, and a skin biopsy specimen was taken to provide autologous cultured keratinocytes for later use. During the next 10 weeks, the tissue expanders were regularly injected, achieving an intraperitoneal volume of 2,250 mL and an increase in abdominal girth from 54 cm to 80 cm. This was well tolerated, but supplementary nasogastric tube feeding was required because of anorexia and weight loss. The subcutaneous chest wall expanders became infected and were removed; however, 6 weeks before separation, a cervical subcutaneous tissue expander was inserted and successfully filled to 300 mL. One week before separation, a multidisciplinary planning meeting was held to rehearse all aspects of the operation and postoperative care. Considering the EMG findings, it was decided to leave twin 1 with the bladder and urethra and twin 2 with the anus and rectum.

From the Departments of Paediattic, Urologic, and Plastic Surge’?: The Hospital for Sick Children, London, England. Date accepted: April 22, 1993. Address reprint requests to M.D. Stringer, MD, Department of Paediatric Surgery, Clarendon Wing, The General Infirmary at Leeds, Belmont Grove, Leeds LS2 9NS, England. Copyright 0 I994 by W.B. Saunders Company 0022-346819412904-OOOl$O3.OOlO

477

SPITZ ET AL

478

established.

The tissue expanders

were deflated

before

positioning

the twins in the prone

position. After separation of the upper arms, the skin and subcutaneous tissue of the back were incised in the midline. from the shoulder to the coccyx. The wound was covered with a sterile adhesive plastic drape before the twins were returned to the supine position. A midline incision was made from the shoulder to the pubis. After an initial exploratory laparotomy, the chest wall was divided. and the common pericardial envelope was bisected and reconstructed as separate pericardial sacs. The hepatic bridge was divided using ultrasonic dissection and diathermy, and hemostasis was achieved with sutures and fibrin sealant. Twin 2’s ileum was divided at the point of small bowel fusion and anastomosed to the proximal transverse colon. An initial attempt to preserve the ileocecal region failed: it was inadvertently devascularized because the unusual vascular anatomy was not fully appreciated. The ileum of twin 1 was preserved to the ileocecal valve and exteriorized as a terminal stoma. Most of the bladder was retained by twin I in continuity with the urethra. while a small segment adjacent to the left ureteric orifice was tubularized and exteriorized as a vesicostomy in twin 2. The uterus and vagina were bisected in the sagittal plane and repaired over Silastic stents. After ligation of multiple bridging vessels, complete separation of the twins was achieved. Two surgical teams were involved in the reconstructive phase of Table 1. Anatomic Findings

Musculoskeletal Separate, complete racic deformity

vertebral columns,

&fused

diaphragms;

each with hemipeivis; thoracic scoliosis

tho-

(twin 2);

bony fusion of scapular necks, pelves, & ribs; soft tissue union of conjoined

upper limbs Cardiovascular

Structurally

normal & separate hearts in a common

independent

pericardial

vena cavas & aortas; each aorta terminated

single common

sac;

as a

iliac artery; large single ileocolic artery from

SMA (twin 1) and single IMA from twin 2; hepatic, pelvic, & scapular bridging vessels with cross circulation Gastrointestinal Independent

small bowels united 20 cm proximal

valve; single large colon and rectum; anal sphincter

& puborectalis

slightly better contribution

innervation

from ipsilateral

to ileocecal of external

spinal cord, but

from twin 2 Hepatobiliary

Fusion and overlap of left hepatic lobes; normal, separate extrahe. patic portal venous & biliary systems & hepatic veins Genitourinary Single kidney in each, but pelvic position

in twin 1; separate ipsi-

lateral renal vessels and ureters; single bladder with two ureteric orifices; Fig 1.

Appearance of the conjoined twins at time of referral.

single urethra, vagina, & uterus; single pelvic ovary in

each, but extra ovary at lower pole of kidney in twin 2 Other

Separation On April 1, 1992 the twins were 3 years 7 months old and weighed 16.5 kg. Each was anesthetized. independent arterial and central venous access were obtained, and full monitoring was

Pancreas and spleen in each twin Abbreviations: teric artery.

SMA, superior mesenteric

artery; IMA, inferior mesen-

SEPARATION

OF CONJOINED

479

TWINS

to cardiopulmonary

resuscitation.

grafts were harvested.

During

and the twin died.

identify the cause of death, but the myocardium. cally normal. appeared

I required

Twin required

although histologi-

pale and poorly developed.

intensive therapy for 2 weeks. Her ureteric stent

replacement

tive problems

Split skin

the autopsy. it was not possible to

hy open cystotomy; however, her postopera-

were otherwise

confined

split akin was usefully applied wall. and the abdominal

to the wound.

to granulating

Homograft

areas on the chest

wound edges were approximated

by serial

tucks in the prolcnc mesh. Four weeks later, her abdominal drhisced,

and new prolcne

ingrowth of granulation subsequent

intense

mesh was applied.

wound

On this occasion,

tissue through the mesh was awaited,

wound

contraction

mesh. Sheets of autologous cultured

enabled

keratinocytes

excision

and

of the

were applied to

accelerate wound healing. The twin was discharged home 4 months after

separation

treutmcnt mrnt

(Fig

awaiting

and has since undergone

successful

lithotripsy

ot two small hladder calculi and further wound debride4).

She continues

readmission

to receive

physiotherapy

and

is

for a lower limb prosthesis and release of a

Icft elbow contracturc.

DISCUSSION

The

reported

incidence

of conjoined

twins is

150,000 to 1:200,000 births, and more than two thirds

are femalc.‘-J Despite their monozygotic origin, they may vary considerably in size, appearance, internal

Fig 2.

Diagrammatic

the operation.

Despite

a huge abdominal diaphragm,

illustration of the anatomic findings.

the tissue expansion, chest wall defects and

defect

remained

incisions. which enabled

the approximated

convex. In twin 1. a pectoralis medially to obtain further skin was applied Edinburgh, entially

repair

of the

ribs to become

England)

more

major muscle flap was transposed

chest wall coverage.

to exposed tissues. Prolene with a polythene

to close the

operating

(Fig 3). After

thoracic closure was achieved with the aid of lateral rib

abdominal

Meshed

allogeneic

mesh (Ethicon

Ltd.

liner was sutured circumfer-

wall

in each

twin.

time was IS hours, and the estimated

The

blood

total

Ioss was

1,800 ml..

Postoperative Results The twins were paralyzed and ventilated, sive care support. Twin 2 remained eral perfusion. teriorated

hyperpyrexia,

and coagulopathy.

and treatment

day. hypotension

(microbiological

de-

inotropic

cultures were

with steroids. On the third postoperative

developed.

line; an echocardiogram

which was unresponsive

showed an overloaded

tile left ventricle with no pericardial pulmonary

Her condition

despite aggressive fluid and blood replacement.

support. a change of antimicrobials negative),

and received full inten-

critically ill. with poor periph-

to adrena-

and poorly contrac-

effusion. Attempts

to measure

capillary wedge pressure were unsuccessful. The follow-

ing day. profound

hradycardia

developed,

which was unresponsive

Fig 3. Immediate postoperative appearance extensive abdominal and chest wall defects.

of twin 1. Note the

480

Fig 4. Appearances separation.

SPITZ ET AL

of the surviving twin’s wound 8 months after

anatomy, and personality.l*“Bj When separation is both anatomically feasible and nonurgent, the optimal time for surgery is probably during infancy.1,6,7 Later division, as in the present case, adds to the psychological and physical problems of separation, not least because there is an increase in postural deformities and a decrease in thoracic flexibility with age. The importance of detailed investigation and careful multidisciplinary assessment before separation cannot be overstated. In our case, magnetic resonance imaging provided excellent anatomic detail,x but angiography was an invaluable adjunct in precisely defining the vascular supply to the bowel and kidneys. Nevertheless, there were operative difficulties because the dual blood supply to the mobile single colon was not symmetrical; there was a dominant ileocolic supply from twin 1, and only one inferior mesenteric artery originated from twin 2. The body wall and skin defects resulting from separation posed the greatest challenge in the separation of these twins. A myocutaneous flap derived from either the common fused limb of ischiopagus tripus twins’,’ or from a nonsalvageable twin was not available. Prosthetic material has been used by others, but it has the associated complications of infec-

tion and dehiscence.5,6,“’ Relaxing incisions are associated with a prohibitive morbidity.lt,lz Successful expansion of the abdominal cavity by artificial pneumoperitoneum has been reported, but the final increase in abdominal girth was less than 20 cms13~‘J;in our case it was 26 cm. Subcutaneous tissue expanders have undoubtedly assisted primary skin closure in cases of thoracopagus twins.15,‘hZuker et al (1986) first reported the use of intraperitoneal tissue expanders in the separation of ischiopagus tetrapus twins, although the expansion achieved was insufficient to allow complete primary closure.h Our previous experience with abdominal tissue expansion confirmed the value of the intraperitoneal site,’ which was well tolerated by our patients. However, the same degree of expansion could probably have been achieved in 8 rather than 11 weeks, thus reducing the period of anorexia. Despite tissue expansion, the degree of union in this case demanded the extensive use of prosthetic material. Skin cover was aided by a variety of techniques, including the novel use of autologous cultured keratinocytes. The cause of death in twin 2 remains uncertain. The clinical picture suggested uncontrolled sepsis; however, all microbial cultures were negative, autopsy findings were not supportive, and there was no clinical response to broad spectrum antibiotics and antifungal agents. Adrenal insufficiency in conjoined twins However, in our case there was has been reported. I7316 no improvement with hydrocortisone, and the adrenal gland was found to be histologically normal at the time of autopsy. The thoracic closure was not unduly tight,7 and the echocardiographic findings were not indicative of such a problem. Myocardial insufficiency after separation is a possible cause. When conjoined, twin 2 had a consistently higher resting pulse rate than twin 1 and may have been partially dependent on twin l’s cardiac output. There were no preoperative studies of cardiac output or attempts to quantitate the degree of vascular shunting. Twin 1 is healthy and thriving 8 months after separation. She requires regular physiotherapy, currently to correct postural deformities, and in the future to encourage walking with an artificial limb. Additional surgery will be required to improve the function in her left arm. As with other ischiopagus twins who have survived separation, this twin may also need further treatment to establish full urinary continence.‘y,zO ACKNOWLEDGMENT The authors acknowledge the skill and dedication of their medical and nursing colleagues involved in the care of the twins. They also thank Professor I.M. Leigh of the Experimental Dermatology Laboratory, The Royal London Hospital, for providing the cultured keratinocytes.

SEPARATION

OF CONJOINED

481

TWINS

REFERENCES 1. Spitz L, Capps SNJ, Kiely EM: Xiphoomphaloischiopagus tripus conjoined twins: Successful separation following abdominal wall expansion. J Pediatr Surg 26:26-29, 1991 2. Hanson JW: Incidence of conjoined twinning. Lancet 2:1257, 1975 3. Edmonds LD. Layde PM: Conjoined twins in the United States, 1970-1977. Teratology 25:301-308, 1982 4. Hoyle RM: Surgical separation of conjoined twins. Surg Gynecol Obstet 170:549-562,199O 5. Boles ET Jr. Vassy LE: Thoraco-omphalopagus conjoined twins: Successful surgical separation. Surgery 86:485-492. 1979 6. Zuker RM, Filler RM. Lalla R: Intra-abdominal tissue expansion: An adjunct in the separation of conjoined twins. J Pediatr Surg21:1198-1200, 1986 7. O’Neill JA, Holcomb GW, Schnaufer L, et al: Surgical experience with thirteen conjoined twins. Ann Surg 208:299-312, 1988 8. Richardson RJ, Applebaum H, Taber P, et al: Use of magnetic resonance imaging in planning the separation of omphalopagus conjoined twins. J Pediatr Surg 24:683-684, 1989 9. Mestel AL, Golinko RJ, Wax SH. et al: Ischiopagus tripus conjoined twins: Case report of a successful separation. Surgery 69:75-83, 1971 10. Hisano K, Nakamura K, Okada M. et al: Separation of conjoined twins using chest wall prosthesis. J Pediatr Surg 24:928929, 1989

11. Peterson CG, Hill AJ Jr: Separation of conjoined thoracopagus twins. Ann Surg 152:717-729. 1960 12. She YX. Li ZC. Song LC, et al: Successful separation of xipho-omphalopagus twins. Z Kinderchir 40:237-240. 1985 13. Eades JW, Thomas CG Jr: Successful separation of ischiopagus tetrapus conjoined twins. Ann Surg 164:1059-1072, 1966 14. Hung WT. Chen WJ, Chen HT, et al: Successful separation of ischiopagus tripus conjoined twins. J Pediatr Surg 21:920-923, 1986 15. Ricketts RR, Zubowicz VN: Use of tissue expansion for separation and primary closure of thoracopagus twins. Pediatr Surg Int 2:365-368,1987 16. Elias DL, Baird WL, Zubowicz VN: Applications and complications of tissue expansion in pediatric patients. J Pediatr Surg26:15-21, 1991 17. Aird I: The conjoined twins of Kano. Br Med J 1:831-837, 1954 18. Diaz JH. Furman EB: Perioperative management of conjoined twins. Anesthesiology 67:965-973, 1987 19. Hoyle RM, Thomas CG Jr: Twenty-three-year follow-up of separated ischiopagus tetrapus conjoined twins. Ann Surg 210:673679, 1989 20. Shapiro E. Fair WR, Ternberg JL, et al: lschiopagus tetrapus twins: Urological aspects of separation and IO-year follow up. J Ural 145:120-125. 1991