The clinical use of the superior vena cava-pulmonary artery shunt: A report of 20 cases

The Clinical Use of the Superior Vena Cava-Pulmonary Artery Shunt: By

A Report

of 20

Cases

BARRYF. SACHS,ROBERTG. PONTIUSANDJAMESR. ZUBERSUHLER

MADE during the past decade in the total correction of cyanotic congenital heart defects has made it essential that the palliative procedures be carefully appraised. Other than pulmonary artery banding and atria1 septectomy, palliation usually takes the form of a vascular shunt. The classical methods of subclavian-pulmonary artery (Blalock-Taussig ) and aortopulmonary artery (Potts-Smith) have been well proven. More recently, the ascending aorto-right pulmonary artery shunt and the superior vena cava-right pulmonary artery shunt have been introduced in an effort to solve some of the problems associated with the classical shunt procedures.1-3 The purpose of this report is to (1) describe our experience with 20 patients who underwent palliation with the superior vena cava-pulmonary artery shunt; (2) to compare these results with previously established shunt procedures; and (3) to describe three instances where the anatomic configuration necessitated a variation in surgical technic and management.

T

HE PROGRESS

SURGICAL TECHNIC The region of the superior vena cava and right pulmonary artery is usually approached through a right anterolateral incision (Fig. 1). After the vessels are isolated, the pressure in the pulmonary artery is measured. The pulmonary artery is then occluded proximally and the change in distal pulmonary artery pressure is recorded. Since function of a superior vena cava-pulmonary artery shunt depends on a low pulmonary artery pressure, this procedure is carried out only if the distal pulmonary artery pressure falls below 10 mm. Hg. If the pressure remains above this level, a systemic pulmonary artery shunt is done. If the proper physiologic conditions are present, proximal ligation and division of the right pulmonary artery is done at the main pulmonary artery bifurcation. The distal pulmonary artery is then anastomosed end to side with the vena cava behind a partial exclusion clamp. The cava is either ligated or divided at the cave-atria1 junction. The advantage of ligation is that it can be released if there is excessive From the Departments of Surgery and Pediatrics, Children’s Hospital of Pittsburgh and the University of Pittsburgh, School of Medicine. Supported in part by a grant fTOtn the W. I. Patterson Charitable Fund. BAHRY F. SACHS, M.D.: Clinical Assistant Instructor in Surgery, University of Pittsburgh, Clinical Assistant Professor of Surgery, School of Medicine. ROBERT G. PONTIUS,M.D.: University of Pittsburgh, School of Medicine. JAhlES R. ZUBERBUHLER, M.D.: C&cal Assistant Professor of Pediatrics, University of Pittsburgh, School of Medicine; Director of Cardiology, Children’s Hospital of Pittsburgh. Presented before the Surgical Section, American Academy of Pediatrics, Oct. 21-23, 1967, Washington, D. C. 364

JOURNAL OF PEDIATHICSURGERY,~OL. 3,No.3

(JUNE),

1968

365

SUPERIORVENACAVA-PULMONARYARTERYSHUNT

Fig. L-Schematic view of operatile area. W = End-to-side cavapulmonary anastomosis; X = Distal pulmonary artery and site for pressure monitoring; Y = Proximal occluding clamp; Z = Silk suture around azygos vein for delayed ligation; RA = Right atrium.

postoperative caval obstruction, but division reduces angulation at the anastomosis. Ligation was more frequently used in infants. The azygos vein helps to decompress the superior vena cava and it is either ligated or encircled for delayed occlusion. Postoperatively, the patients are kept in the sitting position to aid caval drainage. Venous pressure in the upper extremities is monitored, and arterial pH, PCOZ, and PO2 are determined frequently. RESULTS

A superior vena cava-pulmonary artery shunt was performed in 20 patients ranging in age from 2 days to 23 years. (Table 1; Fig. 2). Six types of congenital defect were selected for palliation by this technic. The surgical results are related to both the age at operation and the defect present. (Tables 2 and 3). Seven deaths occurred in our series. Five out of 6 children under one year of age expired. The only surviving infant has a single ventricle with pulmonic stenosis. Three of the deaths took place in the first 48 postoperative hours. Chylothorax resulted in one death on the twelfth postoperative day. The fifth death occurred during surgery in a 23-day-old child who had previously undergone pulmonary valvotomy at 5 days of age. Of the older patients, a 12-year-old boy with Ebstein’s malformation died in the postoperative period. The other death occurred in a 3-year-old boy with transposition, pulmonic stenosis, and a ventricular septal defect. This shunt was done despite a distal pulmonary artery pressure of 12 mm. Hg after occlusion. At autopsy, the shunt was thrombosed. There was one late death due to fulminating enteritis 5 years after surgery. In 8 patients, single ventricle with pulmonic stenosis was present; one child was under one year of age at the time of surgery, All 8 survived. Four out of 5

Table

PDA

PDA PDA Small VSD

PFO,

2. F, 5 days, 1961

3. F, 2 days, 1962 4. M, 23 days, 1963 5. F, 6 months, 1960

6. F, 2 months,

Additional Surgery

by C-PA Shunt

Takedown of C-PA shunt, end-to-end right subclavian-pulmonary artery shunt; atrial septectomy done at 6 days.

INFUNDIBULAR ANU VALVULAR PULMONIC STENOSIS

Cardiopulmonary bypass; attempted PFO closure; tracheostomy.

OF THE TRICUSPID VALVE

on Cases Treated

EBSTEIN’S ANOMALY

l.-Data

Left subclavian-pulmonary at 2 years.

PFO, VSD

10. M, 8 years, 1967

1962

shunt

None

(No Catheterization)

9. F, 5 years,

artery

None

(No Catheterization)

1966

VSD

8. F, 5 years, 1962

7. M, 16 months,

1967

(No Catheterization)

at 5 days. at same procedure;

Balloon dilitation of PFO at 1 month; septotomy with C-PA shunt; azygos vein ligation 5 days postoperative. None

TRICUSP~ VALVE ATFIESIA

Atria1 septotomy. Pulmonary valvulotomy Pulmonary valvulotomy tracheostomy.

HYPOPLA~TIC RIGHT VENTHICLE, TRICUSPID STENOSIS, PULMONARY ATRESIA

PFO

Associated Defects

1. M, 12 years, 1960

Year of Surgerv

Case No., Sex, Age, and

later. Living and well 5 yrs. later. Living and well 8 months later. .~_

Died 12 days postoperative from Chylothorax. Living and well, 1 yr. later. Living and well 5 yrs.

Died within 9 hrs. Died at surgery. Died within 3 hrs.

Died within 4 hours after 2nd operation.

Died in 24 hrs.

Result

19Fl

1964

1961

1961

15. hl, 4 years,

16. F, 5 years,

17. F, 6 years,

1962

ok

left superior

levocardia

Coarnros

None

CHAMHER

AND

Intracardiac

VCSTI~~LE wrrrr I~FPUDIBULAH

Septotomy; 1 month

PvLhroslc

STENOSIS repair 5 years after C-PA shunt.

VALVULAR

closed drainage postoperatively.

of chylothorax

Tracheostomy, ligation of left superior vena cava 2 years later. None

Left C-PA shunt; closure of sternal dehisccnce. Cardiac massage during surgery.

OUIFLOW

Result -.-.

and well 5 yrs.

Living and well 5 yrs. later.

later. Living and well 3 yrs. later. Excellent result for 5 yrs. prior to death from enteritis. Living and well 6 yrs. later. Living and well 6 yrs. later. Delivered a normal infant 2 yrs. later.

later. Living and well 4 yrs. later. Living and well 6 yrs.

Living

l>ied within 36 hrs. with thrombosed shunt. .ASLII'~:LAI~NICSTENOSIS

Anal Plr!.hrovrcS%xaSIs

RTCHTVEXTEUCLEWITHPUL~~ONICSTENOSIS

vena cava

DOUBLEOUTLET

(No Catheterization)

Persistent

\Tone

Isolated

None

atresia

HUDIMENTAHS

Tracheostomy

WITH

Pulmonary

VENTRICLE

None

valve

SINGLE

DEFECT

Additionni Smgery

CHEAT \'EsSELS.\'EN.I.lm:ULARSEPTAL ‘Tracheostom>*

VESSELS,

THE

None

OF

A?.rrciated Ikfrcts

GREAT

None

THE

None

‘~nA\hl’OhITIos

20. M, 8 years, 1961

Living and well 6 yrs. None later. ~__ = tricuspid atresia: Hvpo. RV. PA = hypoplastic right ventricle, puLmonic atresia; LEGEND: SV, PS = single ventricle, pulmonic stenosis; TA septaf defect, pulmonie stenosis: DORV’, PS 71 double outlet right ventricle. pufmonic TCV, VSD, PS = transposition of great \~essels, ventricular stenosis; PFO 1 patent foramen ovale: PDA = patent ductus arteriosus.

19. M, 6 years,

1X. F, 23 years, 1961

1961

1963

1.3. hl, 13 months,

14. hl, 2 years,

1967

12. hl, 7 months,

TRANSPOSITION

3 yrars,

No., Sex, Age, and Yearof surgery

Il. ht.

Case

368

SACHS ET AL.

ExPlRE5

I


2

AGE Fig. 2.-Age

3

AT

4

5

OPERATION

6

8

I2

tf1

23

(YEARS)

distribution of patients undergoing C-PA shunt and the relationship

to survival.

children with the diagnosis of tricuspid atresia were successfully palliated. One child with double outlet right ventricle and pulmonic stenosis underwent successful palliation. Anatomic Variations A precise knowledge of the pattern of the superior caval vessels is essential. Preoperative catheterization is of particular importance when a superior cava shunt is being considered.4 In 2 cases, anatomic variations produced important considerations. In a 4-year-old boy with single ventricle and pulmonic stenosis there was inversion of the atria with the superior and inferior vena cavae presenting on the left. A midline stemotomy was used and an anastomosis of the superior vena cava to the left pulmonary artery was done in the left hilar area. Table 2.-Results

of C-PA Shunt in Children under 1 Year;

Relationship

to Anatomic

Malformation*

Number

sv,

PS

TA Hypo. RV TOTAL *Consult

Legend

to Table 1.

Survived

1

1

1

0

4

0

6

1 (17%)

SUPERIOR VENA CAVA-PULMONARY

Table 3.-Results

~~_.__~ _~

of Cava-Pulmonary Artery Shunt in Children over 1 Year; Relationship to the Anatomic Malformation” Number

~_~~~ sv,

PS

TA DORV, PS TGV, VSD, PS Ebstein’s TOTAL *Consult

369

ARTERY SHUNT

Legend

Survived

7

7

4 1 1 1

4 1 0 0

14

_~__

12 (86%)

to Table 1.

An unsuspected left superior vena cava was responsible for the initial poor result seen in a B-year-old girl with single ventricle and puhnonic stenosis (Fig. 3). Her hematocrit remained elevated and she was mildly symptomatic. For these reasons, she was recatheterized 3 years after surgery and a left superior vena cava was noted on the cineangiogram. Ligation of this vessel was successful in establishing the full effectiveness of the cava shunt. Her symptoms and polycythemia cleared.

Fig. 3 .-Cineangiogram demonstrating anomalous left superior vena cava. 1 = Right superior vena cava; 2 = Distal right pulmonary artery; 3 = Left innominate vein; 4 = Left superior vena cava; 5 = Point of communication with heart (left atrium or coronarv sinus).

3io

SACHS

ET AL.

60

70

80

65

t.

60

s 2

55

3 4

50

45

40

35 PRE-OP

POST-OP

IO

20

30

FOLLOW-UP

Fig. 4.-Hematocrit Long-Term

40 (TIME

50

IN MONTHS)

values following cava-pulmonary artery shunt.

Results

Twelve patients have now been followed from 9 months to 7 years. A uniformly good clinical result has been obtained in all of these patients. All 12 patients have minimal cyanosis at rest and mild exertional dyspnea. None of these have had anoxic spells or symptoms consistent with low cardiac output or hypoxia. Postoperative arterial oxygen saturations have not been obtained but serial hematocrits demonstrate a persistent fall (Fig. 4). An analysis of each child’s growth pattern has shown gradual improvement in his or her height and weight percentiles with a single exception. The oldest patient in the series is a woman with single ventricle and pulmanic stenosis who underwent surgery when she was 23 years old. She has been followed for 6 years and her course has been uncomplicated. Two years after surgery, she had a normal pregnancy and a healthy child was delivered vaginally. Total Correction after Cava-Pulmonary Artery Shunt A 13-year-old boy was recatheterized 5 years after the original shunt because of progressive exertional dyspnea. Catheterization and cineangiography demonstrated a valvular and infundibular pulmonic stenosis with a common ventricle. Although no ventricular septum was seen, the right and left portions of the common ventricular chamber appeared well developed and total correction was believed possible. Despite the presence of a cava-pulmonary artery

SUPERIOR VENA

CAVA-PULMONARY

ARTERY SHUNT

Fig. S.-Method of cannulation for cardiopulmonary bypass in the presence of a superior vena cava-pulmonarv artery anastomosis. 1 = Site of anastomosis; 2-= Site of cannulation (superior vena cava); 3 = Point of ligation and division of cavalatria1 junction; 4 = Point of ligation and division of right pulmonary artery; 5 = Curved caval cannula; 6 = Distal pulmonary artery. shunt, cardiopulmonary bypass was accomplished without difficulty. A curved cannula was inserted into the superior vena cava cephalad to the shunt (Fig. 5). A rudimentary septal ridge was found and the defect was closed with a teflon patch. The infundibular and valvular pulmonic stenoses were relieved. The cava-pulmonary artery shunt was left intact. The patient is now asymptomatic, thirteen months after surgery. DISCUSSION

The earliest clinical reports described the use of the superior vena cavapulmonarv, artery shunt in Ebstein’s malformation, 5 tricuspid atresia and steno-

372

SACHS

ET AL.

Table 4.-Comparison of Systemic-Pulmonary Artery and Cava-Pulmonary Artery Shunts; Early and Late Survival in Children under 1 Year” Number

SA-PA SHUNT C-PA SHUNT

Survived

20 6

16 1

Now Alive

S (40%) 1 (17%) -.

*Consult Legend to Table 1.

sis,6 and transposition with pulmonic stenosis. 7,8 Glenn’s collected series of 537 cases describes its use in a variety of other defects.s In order to evaluate our findings critically, they must be compared with the results obtained after palliation with the systemic pulmonary artery shunt. Accordingly, we reviewed our experience with 33 patients having Blalock or Potts procedures for the same anatomic lesions. The data relating to both shunts was divided into two groups; patients under and patients over one year of age at the time of surgery. Only 1 of 6 children under one year survived the superior vena cava-puhnonary artery shunt (Table 4). This patient is doing well 5 years postoperatively. Eighty per cent of our patients under one year (16 of 20) survived systemicpulmonary artery shunt. However, 8 of these 16 initial survivors eventually died due to congestive heart failure or complications associated with the initial shunting procedure. This reduced the long-term survival to 40 per cent. Table 5.-Comparison Artery

of Systemic-Pulmonary Artery and Cava-Pulmonary Shunts; Early and Late Survival in Children over 1 Year Number

SA-PA SHUNT C-PA SHUNT

Survived

Now Alive

9 12

7 (54%) 11 (80%)

13 14

Similar survival statistics after systemic pulmonary artery shunts have been reported by others.l”J1 In children over one year of age, there was an 86 per cent (12 of 14) surgical survival with the cava-pulmonary artery shunt (Table 5). There was one late death of noncardiac origin. The long term survival was 80 per cent. In the 13 patients over one year with a systemic artery-pulmonary artery shunt, there was an early survival rate of 69 per cent (9 of 13). Two late deaths reduced the long-term survival to 54 per cent. One of the most important advantages of the cava-pulmonary artery shunt is the absence of postoperative failure (Table 6). Comparing the current clinical status of survivors, we have found that none of the 12 patients surviving the cava-pulmonary artery shunt are receiving digitalis. However, digitalis is still necessary in 66 per cent (10 of 15) of systemic-pulmonary artery shunt surTable &-Comparison

of Long-Term Requirements

Management

for Digitalis

Present Survivors

SA-PA SHUNT C-PA SHUNT

15 12

of Present Survivors; Digtalis Rx

10 (66%) 0 (0%)

SUPERIOR VJ3NA CAVA-PULMONARY

ARTERY SHUNT

373

vivors. In Glenn’s study of 38 cases, there were no instances of congestive failure even after a 4-5 year follow up. 12 This advantage of the cava-pulmonary artery shunt is consistent with the reduced right ventricular load expected when part of the systemic venous return is diverted from the right ventricle. The reduced incidence of right-sided congestive heart failure in tricuspid atresia may also be due to the decrease in blood flow through the small intraatria1 communication brought about by redirecting part of the cardiac return from the right atrium to the pulmonary artery. However, atria1 septectomy may still be necessary in some of these patients. Two contraindications are generally noted for this procedure: ( 1) pulmonary hypertension or evidence of increased distal resistance and (2) diameter of the pulmonary artery less than one half of the superior vena cava.Q~*2 The above two limitations are encountered most frequently in the newborn and in infants under 6 months of age, and are in part responsible for the high mortality seen in this age group. We currently use the distal pulmonary artery pressure after proximal occlusion as the major criterion for shunting. When the pulmonary artery pressure distal to the occluding clamp is under 10 mm. Hg, we feel that the proper physiologic conditions are present. On the one occasion when a superior vena cava-pulmonary artery shunt was done in the presence of a pulmonary artery pressure greater than 10 mm. Hg, thrombosis of the shunt was demonstrated at autopsy. The direct measurement of pressure rather than physical measurement of vessel size appears preferable in deciding upon the use of a caval shunt, The superior cava syndrome was seen in four patients. This was usually mild, lasting only 2-3 days and was best relieved by position. Fifteen of Glenn’s 38 patients had some degree of obstruction, and I4 were under 5 years of age. Two of our patients were under 5. Edwards and Bargeron have recently emphasized the importance of correcting the hypovolemia that occurs due to impaired caval flow.13 Right atria1 pressure is monitored and maintained at 10-12 cm. H20. They use a mixture of % lactated Ringer’s solution and % Dextran at a rate that maintains this pressure. We have not used this technic, but it appears to be a significant contribution in postoperative management.14 One method suggested by the same authors for reducing obstructive caval complications is delayed ligation of the azygos vein.15 This was employed in a 2-month-infant with tricuspid atresia. At surgery, a 2-O silk suture was looped around the vein and brought out through the chest incision. By the fifth day, the child had adjusted to the transient superior caval obstruction and the silk was tied. This closed the decompressing azygos vein and redirected all the flow through the anastomosis. It was our impression that this maneuver reduced the severity of the symptoms of impaired superior cava drainage. CONCLUSIONS In patients over one year of age with tricuspid atresia or single ventricle and pulmonic stenosis, the superior vena cava-pulmonary artery anastomosis in the shunt of choice. Although our data indicates that in infants the systemic-

374

SACHS

ET AL.

pulmonary artery shunt is associated with greater survival, the results reported recently at other centers suggests that the caval shunt may be preferable in this age group. One of the main advantages of the superior vena cava-pulmonary artery shunt is the absence of congestive failure and the need for digitalis therapy. The intraoperative measurement of pulmonary artery pressures is essential in deciding whether the proper physiologic conditions are present for the shunt to function. Preoperative angiograms are desirable for the identification and appropriate management of cava anomalies. Failure to improve after a superior cava shunt is an indication for recatheterization. Successful total correction of a patient with single ventricle and pulmonic stenosis 5 years after a superior vena cava-right pulmonary artery shunt is reported. SUMMARIO

IN INTERLINGUA

Shunting inter vena cave superior e arteria pulmonar esseva effectuate in 20 patientes con congenite defectos cyanotic. Le procedimento es le therapia de election in patientes de plus que un anno de etate qui ha un sol ventriculo, stenose pulmonic, e atresia tricuspidic. Es describite le uso de1 tension arterial pro definir le .operabilitate, le tardive ligation de1 vena azygotic, e le maneamento de1 provision de liquido. Le recognition de abnormalitates caval (si tales es presente) es importantissime pro un efficace programma de tractamento e pote esser effectuate per catheterismo. In un case de ventriculo unit con stenose pulmonic, palliation esseva obtenite per medio de un shunting caval, sequite -cinque annos plus tarde-per un correction total in que le shunting remaneva intacte e que se terminava a bon successo. REFERENCES 1. Cooley, D. A., and Hallman, G. L.: Surgical Treatment of Congenital Heart Disease. Philadelphia, Lea & Febiger, 1966. 2. Glenn, W. W. L., and Patino, J. F.: Circulatory by-pass of the right heart. I. Preliminary observations on the direct delivery of vena caval blood into the pulmonary arterial circulation. Azygos vein-pulmonary artery shunt. Yale J. Biol. Med. 27: 147-151,1954. 3. Glenn, W. W. L.: Circulatory bypass of right side of the heart. IV. Shunt between superior vena cava and distal right pulmonary artery: Report of clinical application. New Eng. J. Med. 259:117-120, 1958. 4. Shumacker, H. B., Jr., King, H., and Waldhausen, J. A.: The persistent left superior vena cava. Surgical implications, with special reference to caval drainage into the left atrium. Ann. Surg. 165:797, 1967. 5. Gasul, B. M., Weinberg, M., Jr., Luan, L. L., Fell, E. H., Bicoff, J., and Steiger, Z.: Superior vena cava-right main pulmonary artery anastomosis: surgical correction for patients with Ebstein’s anomaly and for congenital hypoplastic right ventricle. J.A.M.A. 171:1797-1803, 1959.

6. Cumming, G. R., Ferguson, C. C., Briggs, J. N., and Brownell, E. G.: Tricuspid atresia: Treatment by superior vena cava-pulmonary artery anastomosis. J. Thorat. Cardiov. Surg. 40:31-34, 1960. 7. Sanger, P. W., Robicsek, F., and Taylor, F. H.: Vena cava-pulmonary artery anastomosis. III. Successful operation in case of complete transposition of great vessels with interatrial septal defect and pulmonary stenosis. J. Thorac. Cardiov. Surg. 38166-171, 1959. 8. Robiscek, F., Sanger, P. W., and Taylor, F. H.: Three year follow-up of a patient with transposition of the great vessels, atria1 septal defect, and pulmonary stenosis treated by vena cava-pulmonary artery anastomosis. J. Thorac. Cardiov. Surg. 44:817-820, 1962. 9. Glenn, W. W. L., Browne, M., and Whittemore, R. : Circulatory bypass of the right side of the heart: cava-pulmonary artery shunt-indications and results (Report of a collected series of 537 cases). In Cassels, D. E. (Ed.): The Heart and Circulation in the Newborn and Infant. New York, Grune & Stratton, 1966. 10. Cooley, D. A., and Hallman, G. L.:

SUPERIOR VENA CAVA-PULMONARY

ARTERY SHUN1

Surgery during the first year of life for cardiovascular anomalies: a review of 500 consecutive operations. J. Cardiov. Surg. 5:584, 1964. 11. Gerbode, F., O’Brien, M. F., Kerth, W. J., and Robinson, S. J.: Surgical aspects of heart disease under the age of two years. J. Cardiov. Surg. 5:591, 1964. 12. Glenn, W. W. L., Ordway, N. K., Talmer, N. S., and Call, E. P. Jr.: Circulatory bypass of right side of the heart. VI. Shunt between superior vena cava and distal right pulmonary artery: Report of clinical application in thirty-eight cases. Circulation 31:172-189,196.~.

375

13. Bargeron, L. M., Jr., and Edwards, W. S., III: The importance of an adequate circulating blood vohrme foIlowing superior vena cava-right pulmonary artery anastomosis. Surgery S&865-868, 1965. 14. Edwards, W. S., and Bargeron, L. M., Jr.: The superiority of the Glenn Operation for tricuspid atresia in infancy and childhood. J. Thorac. Cardiov. Surg. 55:60-69. 1968. 15. Edwards, W. S., and Bargeron, L. M., Jr.: The importance of the azygos vein in superior vena cava-pulmonary artery anastomosis. J. Thorac. Cardiov. Surg. 46:811, 1963.