New Techniques in the Diagnosis and Operative Management of Siamese Twins By David Miller, Paul Colombani, James R. Buck, David I_. Dudgeon, and J Alex Hailer, Jr Baltimore, Maryland New techniques of 2-D sonography and radionu- cleotide Disofenin scanning allowed noninvasive evaluation of thoracoomphalopagus Siamese twins and successful separation at four days of age. Twin girls joined at the lower sternum and upper abdomen and weighing 15 Ibs. were transferred at five hours of age after caesarian-section delivery, Scout films revealed high intestinal obstruction in twin A. 2-D sonography showed separate and normal hearts with different rates and attached pericardial sacs, Labeled Disofenin given intravenously to twin A was excreted exclusively in her gallbladder and bile ducts; vice versa for twin B. Because operation was necessary to correct jejunal atresia in twin A, further growth and development was not an option and the parents agreed to total correction. Sternal and peri- cardial separation and division of common midline- liver was followed by primary diaphragmatic defect repair and Dacron-cloth fascial reconstruction to upper abdominal wall and complete soft-tissue and skin closure in a ten-hour operation. Segmental jejunal resection and anastomosis with gastrostomy was added in baby A. The new tests greatly simpli- fied definition of the anatomical relationships and implemented rapid correction in these newborn con- joint twins. INDEX WORDS: Conjoined twins; thoracoomphalo- pagus twins CASE REPORTS Following an uncomplicated pregnancy with expected twins, a 27-year-old woman delivered female conjoined twins at 36 weeks gestation. After a trial period of normal labor with intended vaginal delivery, a midtransverse arrest of the first twin occurred and the baby's head failed to progress. At cesarean section, a surprised obstetrician delivered his second set of Siamese twins. (His first set had been stillborn). With a combined weight of 6750 g, they were joined ventrally from the lower sternum to approximately 3 cm below a small common omphalocele, with a six-vessel umbilical cord con- taining four arteries and two veins (Fig. 1). Lateral rib fusion was absent. Twin A was depressed with Apgars of 0, 1, and 3 at 1, 5, and 30 minutes respectively. After suctioning a moderate amount of thick meconium-stained fluid from the posterior pharynx, an endotracheal tube was inserted and the infant placed on a ventilator at 40% Fio 2. The initial arterial blood gas (ABG) returned Po2 41, Pco 2 57, and pH 7.06. A dusky color, marked restlessness, irritability, tremor and occasional myoclonic activity were noted. ABG on room air showed improvement with PO~ 67, Pco2 36, and pH 7.34, and the endotracheal tube was removed. Twin B was stable with Apgars of 7 and 9 at 1 and 5 minutes and did not require resuscitation. The babies were transferred by ambulance to the Johns Hopkins Children's Center and arrived in good condition within 3.5 hours. Both infants appeared active, alert, and well-perfused. There was no evidence of cardiopulmonary distress. A thoracoomphalopagus defect was confirmed with a common umbilical cord, union of the xiphisternum, and probably fused liver (Fig. 1). Abdominal x-rays revealed a markedly dilated loop of bowel in twin A that did not decompress with nasogastric suction (Fig. 2). Dark, bilious drainage was noted from twin A, while the aspirate from twin B was almost clear, and less in volume. An upper gastrointestinal study (Fig. 3) on twin A showed a normal stomach and duodenum, with segmental dilatation of the proximal jejunum and pooling of contrast in the dilated loop of bowel. By the following day contrast had reached the rectum confirming an intact bowel with a very high grade obstruction. There was no crossover of contrast into the intestinal tract of twin B. Due to the small-bowel obstruction in twin A, surgery could not be postponed. To determine operability, the most pressing matter was to document separate and complete hearts. Using standard electrocardiography, two distinct and separate QRS complexes were seen, with different heart rates. Two-dimensional echocardiography showed separate hearts with normal function and structure in each but quite different rates. On the basis of this, cardiac catheterization was omitted. Ultrasonography confirmed two kidneys in each infant with no evidence of hydronephrosis. Sequential hepatobiliary studies were performed with injection of Disofenin (diisopropyl iminodiacetic acid) (New England Nuclear, North Billerica, Mass.) in infant B, fol- lowed by infant A. Using continuous scanning with computer analysis, focal uptake of radiotracer was documented in the heart, liver, and gallbladder of twin B with no crossover (Fig. 4). Similarly, radioisotope injection in twin A demostrated a separate heart, liver, and gallbladder with no enhancement in the other twin (Fig. 5). CT (computerized axial tomography) scan confirmed a fused liver with the majority of the hepatic mass seen in twin B. From the Johns Hopkins School of Medicine, Baltimore, Md. Presented before the 31st Annual Meeting of the Surgical Section of the American Academy of Pediatrics, New York, New York, October 23-24, 1982. Address reprint requests to J Alex Hailer, Jr, MD, the Johns Hopkins School of Medicine, Baltimore, hid 21205. 1983 by Grune & Stratton, Inc. 0022-3468/83/1804--0008/$01.00/0 Journal of Pediatric Surgery, Vol. 1B, No. 4 {August), 1983 373
Transcript
New Techniques in the Diagnosis and Operative Management of Siamese Twins
By David Miller, Paul Colombani, James R. Buck, David I_. Dudgeon, and J Alex Hailer, Jr Baltimore, Maryland
�9 New techniques of 2-D sonography and radionu- cleotide Disofenin scanning allowed noninvasive evaluation of thoracoomphalopagus Siamese twins and successful separation at four days of age. Twin girls joined at the lower sternum and upper abdomen and weighing 15 Ibs. were transferred at five hours of age after caesarian-section delivery, Scout films revealed high intestinal obstruction in twin A. 2-D sonography showed separate and normal hearts with different rates and attached pericardial sacs, Labeled Disofenin given intravenously to twin A was excreted exclusively in her gallbladder and bile ducts; vice versa for twin B. Because operation was necessary to correct jejunal atresia in twin A, further growth and development was not an option and the parents agreed to total correction. Sternal and peri- cardial separation and division of common midline- liver was followed by primary diaphragmatic defect repair and Dacron-cloth fascial reconstruction to upper abdominal wall and complete soft-tissue and skin closure in a ten-hour operation. Segmental jejunal resection and anastomosis with gastrostomy was added in baby A. The new tests greatly simpli- fied definition of the anatomical relationships and implemented rapid correction in these newborn con- joint twins.
INDEX WORDS: Conjoined twins; thoracoomphalo- pagus twins
CASE REPORTS
Following an uncomplicated pregnancy with expected twins, a 27-year-old woman delivered female conjoined twins at 36 weeks gestation. After a trial period of normal labor with intended vaginal delivery, a midtransverse arrest of the first twin occurred and the baby's head failed to progress. At cesarean section, a surprised obstetrician delivered his second set of Siamese twins. (His first set had been stillborn). With a combined weight of 6750 g, they were joined ventrally from the lower sternum to approximately 3 cm below a small common omphalocele, with a six-vessel umbilical cord con- taining four arteries and two veins (Fig. 1). Lateral rib fusion was absent.
Twin A was depressed with Apgars of 0, 1, and 3 at 1, 5, and 30 minutes respectively. After suctioning a moderate amount of thick meconium-stained fluid from the posterior pharynx, an endotracheal tube was inserted and the infant placed on a ventilator at 40% Fio 2. The initial arterial blood gas (ABG) returned Po2 41, Pco 2 57, and pH 7.06. A dusky color, marked restlessness, irritability, tremor and occasional myoclonic activity were noted. ABG on room air showed improvement with PO~ 67, Pco2 36, and pH 7.34, and the endotracheal tube was removed. Twin B was stable with
Apgars of 7 and 9 at 1 and 5 minutes and did not require resuscitation.
The babies were transferred by ambulance to the Johns Hopkins Children's Center and arrived in good condition within 3.5 hours. Both infants appeared active, alert, and well-perfused. There was no evidence of cardiopulmonary distress. A thoracoomphalopagus defect was confirmed with a common umbilical cord, union of the xiphisternum, and probably fused liver (Fig. 1).
Abdominal x-rays revealed a markedly dilated loop of bowel in twin A that did not decompress with nasogastric suction (Fig. 2). Dark, bilious drainage was noted from twin A, while the aspirate from twin B was almost clear, and less in volume.
An upper gastrointestinal study (Fig. 3) on twin A showed a normal stomach and duodenum, with segmental dilatation of the proximal jejunum and pooling of contrast in the dilated loop of bowel. By the following day contrast had reached the rectum confirming an intact bowel with a very high grade obstruction. There was no crossover of contrast into the intestinal tract of twin B.
Due to the small-bowel obstruction in twin A, surgery could not be postponed. To determine operability, the most pressing matter was to document separate and complete hearts. Using standard electrocardiography, two distinct and separate QRS complexes were seen, with different heart rates. Two-dimensional echocardiography showed separate hearts with normal function and structure in each but quite different rates. On the basis of this, cardiac catheterization was omitted.
Ultrasonography confirmed two kidneys in each infant with no evidence of hydronephrosis.
Sequential hepatobiliary studies were performed with injection of Disofenin (diisopropyl iminodiacetic acid) (New England Nuclear, North Billerica, Mass.) in infant B, fol- lowed by infant A. Using continuous scanning with computer analysis, focal uptake of radiotracer was documented in the heart, liver, and gallbladder of twin B with no crossover (Fig. 4). Similarly, radioisotope injection in twin A demostrated a separate heart, liver, and gallbladder with no enhancement in the other twin (Fig. 5). CT (computerized axial tomography) scan confirmed a fused liver with the majority of the hepatic mass seen in twin B.
From the Johns Hopkins School of Medicine, Baltimore, Md.
Presented before the 31st Annual Meeting of the Surgical Section of the American Academy of Pediatrics, New York, New York, October 23-24, 1982.
Address reprint requests to J Alex Hailer, Jr, MD, the Johns Hopkins School of Medicine, Baltimore, hid 21205.
�9 1983 by Grune & Stratton, Inc. 0022-3468/83/1804--0008/$01.00/0
The operative team consisted of 8 surgeons, 7 anesthesiol- ogists, 5 nurses, and 2 anesthesiology technicians. The two anesthesiology teams wore different colored surgical gowns to avoid confusion in monitoring the infants. The group had met on two occasions to rehearse and review the planned anes- thetic induction, intraoperative monitoring, draping proce- dure, and operative approach.
Following mask-induction each infant was separately intu- bated. Radial artery, central venous, and urinary catheters were inserted. Temperature was monitored by esophageal probes. Induction of anesthesia and preparation for monitor- ing required approximately five hours.
With the twins in a lateral decubitus position, an abdomi- nal incision was made in the central portion of the skin bridge. A common peritoneal cavity was entered. The liver of twin A was rotated approximately 90 ~ anteriorly and fused with the liver of twin B, which was rotated 90 ~ in the opposite direction. Separate gallbladders were verified. The duode- num and proximal je junum of twin A were very dilated down
Fig. 3. Twin A - - U G I study demonstrates marked dila- tation of proximal jejunum (arrow}.
to a stenotic point. The remainder of the intestine both above and below the area of focal dilatation was normal and there was no connection to the other twin. Infant B's intestine was in continuity with minimal dilatation despite malrotation and the presence of Ladd's bands.
The incision was extended cephalad to the sternal edge. The common xiphoid and fused eighth ribs were divided. The
Fig. 2. A markedly distended loop of bowel was pres- ent in twin A.
Fig. 4. A t 30 minutes following injection of radiotracer in infant B. contrast is present in the liver and gallbladder (arrow). There is no crossover to twin A.
SIAMESE rWINS: OPERATIVE MANAGEMENT 375
Fig. 5. A t 60 minutes following injection of tracer in infant A, both gallbladders are outlined (arrows) and there is no enhancement in tw in B by computer analysis of continuous scanning.
commonly shared anterior diaphragm was split to reveal two separate hearts, independently beating in their own pericar- dial sacs which were fused.
It was possible to separate the pericardial sacs without entering either the pericardium or pleural cavity. Further incision of the diaphragm posteriorly (toward the table) exposed the bare area of the common liver bridge. An oblique plane of potential cleavage was discovered with separate gallbladders on either side. Using manual control, electrocau- tery, and mattress sutures, the liver was divided with a minimum of blood loss. The remaining soft-tissue bridge was then incised using the cutting current electrocautery.
The twins were individually reprepped and draped and placed on separate operating tables where two different teams completed the reconstructions.
In twin A, the obstructed jejunum was resected back to the second and third portion of the duodenum which was less dilated. An end-to-end anastomosis was performed with interrupted 4-0 silk sutures. A gastrostomy tube was inserted with a silastic feeding catheter along side it, passing around the duodenum, across the anastomosis distally. The appendix was removed. The diaphragm was anchored anteriorly to the undersurface of the sternum and ribs, completely obliterating the defect. This was achieved without undue tension or change in ventilatory pressures.
The upper third of the abdominal fascial defect was covered with a 3 x 4 cm elliptical patch of woven dacron velour. The lower part was closed primarily using 2-0 Vicryl suture. The skin and subcutaneous tissues were mobilized widely to permit primary closure.
In twin B, a partial duodenal obstruction was present due to Ladd's bands and a partial midgut volvulus of 90 ~ A Ladd's procedure was performed. Closure was similar to that of twin A, requiring a prosthetic patch in the upper midline, just beneath the costosternal angle. Primary skin closure was easily accomplished with mobilization of skin flaps.
Both twins recovered promptly from their operative sepa- ration. Twin B (Francesca) was discharged on postoperative day 39 and at 7 months weighed 15.5 lbs. Twin A (Emily) has had significant alimentation dysfunction due to the
obstructed atonic duodenum and jejunum, but is now on a steady growth curve and weighs 8.5 lbs.
DISCUSSION
Siamese twins occur approx ima te ly once in 50,000 bir ths. 1'2 The ma jo r i ty 3 present with t ho racoompha lopagus union, and 75% of these have conjoined h e a r t s : Liver fusion is found in near ly 80%, 5 with a common bi l iary t ree in 20% of c a s e s :
A l though de lay in separa t ion to allow for growth is ideal, 6 urgent opera t ion is ind ica ted for rup tu red omphalocele , 7 intest inal obst ruct ion, 8 and ear ly de te r iora t ion of one or both twins .9
T h e r e have been no survivors fo l lowing a t t e m p t e d separa t ion of twins with conjoined hearts . Therefore , a thorough and precise ca rd i ac evaluat ion is essential , l z u k a w a and co-workers ~~ have shown tha t the presence of two separa te and independent Q R S complexes on s t anda rd elec- t roca rd iog raphy does not preclude ca rd iac union at the a t r ia l level. They advocate ca rd iac ca the- te r iza t ion with ang ioca rd iography in all cases. In our case, use of two-dimensional echocard iogra- phy ~ gave accura te assessment of both ca rd iac s t ruc ture and motion. W e believe tha t echocar- d iog raphy can be used as a dependab le screening test and, thus, invasive studies can be avoided, unless i n t r aca rd iac abnormal i t i e s are indicated.
Separa t ion may be compl ica ted by absent or shared b i l ia ry systems. 12 Sequent ia l radionucleo- t ide scanning using Disofenin c lear ly demon- s t ra ted separa te ga l lb ladders and in tac t ex t rahe- pat ic b i l ia ry trees in both twins. The degree of shar ing the gas t ro in tes t ina l t rac t is readi ly evalu- a ted by cont ras t rad iography . CT scan and u l t ra - sound can establ ish the presence of kidneys, and intravenous pye lography m a y be useful to docu- men t renal function.
The impor tance of a mul t ip le-disc ip l ine t eam with rehearsa l of all aspects (surgical , anesthet ic , and nursing) of the opera t ive procedure cannot be overemphas ized . 13'14 Al though the ou tcome is influenced by careful p lanning and organ iza t ion f rom all par t ic ipants , the prognosis is often pre- de t e rmined by the under ly ing ana tomy which m a y prec lude successful separat ion.
Once the twins have been separa ted , the indi- v idual associa ted congeni ta l abnormal i t i e s a re usual ly well recognized problems in neonata l surgery and can be appropr i a t e ly m a n a g e d as for a s ingly born infant.
376 MILLER ET AL
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