- Email: [email protected]
Extrathoracically adjustable pulmonary artery banding
J
THORAC CARDIOVASC SURG
86:582-586, 1983
Extrathoracically adjustable pulmonary artery banding A new technique of adjustable pulmonary artery banding is presented. A tourniquet system has been used in eight consecutive infants with complex congenital cardiac anomalies during the past 2 years. They had severe congestive heart failure, and six of them required inotropic support preoperatively. All survived the banding procedure and there were no hospital deaths. Four of the eight infants required additional adjustment of the band to improve hypoxemia or persistent congestive heart failure 3 hours to 4 months postoperatively. Each adjustment was made easily via a small skin incision without thoracotomy. This technique allows fine adjustment by gentle and delicate tightening and loosening of the band during and after operation. so that the technique avoids most mortality and morbidity related to an inappropriate banding and brings satisfactory symptomatic palliation.
Ryusuke Muraoka, M.D., Michio Yokota, M.D., Minoru Aoshima, M.D., Shinichi Nomoto, M.D., Inshin Kyoku, M.D., Akira Kobayashi, M.D., Hiroyuki Nakano, M.D., Ken Veda, M.D., and Akihiro Saito, M.D., Shizuoka, Japan
~h
improvement in operative technique, many cardiac defects can be corrected safely by a primary procedure performed in the first few years of life. However, there are some defects that are not amenable or remain controversial with respect to an early primary repair. I Banding of the pulmonary artery continues to play an important role in the management of such defects to lessen congestive heart failure, to prevent pulmonary vascular disease, and to allow survival until the infant is a suitable candidate for corrective operation. Moreover, recent progress in extra-anatomic repair of complex cardiac anomalies in later childhood- may increase the importance of this procedure. Optimum constriction may not always be possible by the conventional technique, and the degree of pulmonary artery banding once made cannot be changed after operation without thoracotomy. When the constriction is made too loose or too tight, congestive heart failure persists or severe hypoxemia appears. We developed a From the Second Department of Surgery, Fukui Medical School, Fukui, and the Departments of Cardiovascular Surgery and Cardiology, Shizuoka Children's Hospital, Shizuoka, Japan Received for publication Dec. 27, 1982. Accepted for publication Feb. 21, 1983. Address for reprints: Ryusuke Muraoka, M.D., The Second Department of Surgery, Fukui Medical School, 23 Shimoaizuki Matsuoka-cho, Yoshida-gun Fukui-ken 910-11, Japan
582
new technique for pulmonary artery banding that allows adjustment postoperatively if necessary by the use of a small skin incision but without thoracotomy. This article describes the technique and the results of our clinical application.
Patients Between October, 1980, and July, 1982, a total of eight infants with complex congenital heart diseases underwent banding of the pulmonary artery by the technique described herein at the Shizuoka Children's Hospital. Ages ranged from 4 days to 20 months (mean 6.3 ± 7.3 months) and weights between 2.9 and 9.7 kg (mean 4.6 ± 2.3 kg). Table I shows the preoperative diagnosis and other data. The operations were performed on an emergency basis in four infants. All infants had severe congestive heart failure unresponsive to medical therapy. Six of eight patients required inotropic support preoperatively. Their cardiothoracic ratios ranged from 0.62 to 0.68 (mean 0.64 ± 0.03). Two infants with complete transposition of the great arteries (TGA) and ventricular septal defect (YSD) had severe hypoxemia (partial pressure of oxygen in the systemic arterial blood [Pao2] of 41 and 40 mm Hg with the fraction of oxygen in inspired gas [F102] 100%). Both of them had undergone prior surgical creation of an atrial septal defect. The remaining six patients had no significant hypoxemia (Pao2 of 92 to 364 mm Hg with
Volume 86 Number 4 Oc tob er . 19 83
Extrathoracically adjustable pulmonary artery banding
583
Fig. 1. Device enabling extrathoracica lly adjustable pulmonary ar tery band ing. It consists of a microporous expanded polytetrafluoroeth ylene (PTFE) 3 mm graft , a long heavy monofilament nylon ligatu re, a PT FE 5 mm graft, and a narrow hard polyvinyl chloride tube. Left inset: Both ends of the 3 mm PTFE graft are inserted into the 5 mm PTFE graft before the tourniquet is tightened . R ight inset: When the tournique t is tightened, the 3 mm and 5 mm PTFE grafts make an adequate circle for pulmonary artery banding. Direct compression on the nylon ligature and the polyvinyl chloride tube to the pulmonary artery is avoided by the PTFE grafts .
Table I. Preoperative data
Case No.
Age 2 mo
2
3 4
5 6 7
8
13 rna I rna 3 mo 4 days I mo 20 mo 10 rna
Weight (kg)
4.1 4.7
2.9 3.5 2.7 3.2 9.7
5.9
Diagnosis SV, SA, PA at resia, anomalous vessel from Ao to PA, dextrocard ia, polysplenia syndrome" TGA, SV, SA, dextrocard ia TGA, VSO" TGA, VSO eoA, POA, TGA , TA" OORV (doubly committ ed VS D)" TGA , SV , PS (slight) TG A, VSD. post-ASl) creation
CT ratio
Dose of dopamine (Ilgfkgfm inj
0.66
10
0.60 0.62 0.62 0.65 0.68 0.68 0.64
10
10
7 8 6
Legend: CT . Ca rdiothoracic. SV. Single ventricle. SA . Single a trium. PA. Pulmona ry a rtery. Ao, Aorta . TG A. Complete transposition of the great a rteries. (I n the case of SV, this refers to malposition of the grea t ar tcr ies.) VSD. Ventricular septa l defect. CoA . Coarct at ion of the aorta. PDA. Pat ent ductu s a rteriosus. TA . Tr icuspid a tresia . DORV. Double-outlet right ventricle. PS. Pulmona ry stenosis. AS D. At rial septal defect. " Emergency operation .
the Fl02 100%). Four of eight infants required adjustment of the banding 3 hours to 4 months after the operations because of severe hypoxemia or persistent congestive heart failure. Operative technique The tourniquet system for the adjustable pulmonary artery banding consisted of a microporous expanded polytetrafluoroethylene WIFE) graft 3 mm in diame-
ter, a long heavy monofilament nylon ligature, a PTFE graft 5 mm in diameter, a narrow hard silicone-coated polyvinyl chloride tube, and hemoclips (Fig. 1). The 3 mm PTFE graft containing the monofilament nylon ligature was passed around the pulmonary artery. The circumference of the banding is approximately the same as the length of the 3 mm graft. However, since the graft material is compressible longitudinally, the appropriate length of the 3 mm PTFE graft was decided in advance
584
The Journal of Thoracic and Cardiovascular Surgery
Muraoka et al.
Table II. Results of the adjustable pulmonary artery banding (initial operation) Pressure (mm Hg) Diameter of PA (mm) After
Before
Case No.
Before
2.5
30
2 3
20.5 10.0
8.5
54
4
5
11.5 10.0
8.0 8.0
6
10.5
5.8
7
14.0
8.6
8
10.5
7.4
5.5*
I
Systemic systolic pressure
PA mean pressure
I
After
Before
20
84 72 80
32
8.2
39
I
After
Pao} (mm Hg) with Flo} 1.0
Before
I
After
97
57
107
364 41
39 139 25
110
93 52
126
70
40 244
130
22
68
79
340
79
37
27
77
73
207
93
29
25
92
93
92
67
45
43
Legend: PA. Pulmonary artery.
*Anomalous
vessel from the aorta to the pulmonary artery.
by snaring the graft around a Hegar cervical dilator of a diameter equal to that intended for the banded site. The length of the 3 mm graft in this series was from 55 to 75 mm according to the size of the infant and the defect, which allowed the banding to be approximately 20% tighter than that proposed by Trusler and Mustard.' Each end of the nylon ligature was passed through the respective end of a small length (15 to 30 mm) of the 5 mm in diameter PTFE graft and was then passed through a hole prepared in the middle of the 5 mm PTFE graft. Both ends of the nylon ligature were then passed through a polyvinyl chloride tube (7 to 14 em in length) which was prepared from an arterial pressuremonitoring tube. The pulmonary artery was then constricted gradually while systemic and pulmonary arterial pressures, heart rates, and systemic Paoz were being monitored. When the nylon ligature was tightened, the 5 mm graft enclosed each end of the 3 mm graft as a sheath and prevented the direct compression of the nylon ligature on the pulmonary artery (Fig. 2). The approximate size of the constricted pulmonary artery was calculated from the length of the nylon ligature outside the tube and was measured directly by twodimensional echocardiography during the operation. After proper constriction was established, multiple hemoclips were placed firmly around the end of the tube furthest from the pulmonary artery to keep the nylon ligature from slipping within it. The end of the tube with its hemoclips was withdrawn to the level of the anterior chest wall and was buried under the muscular layer. When postoperative adjustment of the tightness of the band was indicated, a small skin incision was made and
the band was readjusted simply by relocating the hemoclips.
Results All eight infants survived the banding procedure, and there were no hospital deaths. Fine and gradual constriction of the pulmonary artery could be done by this method without hemodynamic deterioration even in severely ill infants. The pulmonary artery was constricted to an average of 7.1 ± 2.2 mm in diameter, and mean pressure of the pulmonary artery fell to 29 ± 9 mm Hg. Systemic arterial pressure rose and systemic Paoz fell. Table II shows the data before and after the banding procedure. Postoperative adjustment of the banding was necessitated in four patients; loosening in two to improve hypoxemia and tightening in two to improve persistent congestive heart failure (Table 11). A 55-day-old infant (Case 3) with TGA and VSD had severe hypoxemia and congestive heart failure. Preoperative cardiac catheterization revealed an extremely low POz of the pulmonary vein (36 mm Hg with an Floz of 21%) and of the aorta (29 mm Hg with an F10z of 21%) with a large interatrial communication that had been made by prior balloon atrial septostomy. Therefore, pulmonary artery banding was indicated to improve congestive heart failure as well as hypoxemia. The pulmonary artery of 10.0 mm in diameter was constricted to 8.2 mm in the operating room. Postoperatively, the Paoz persisted below 30 mm Hg with an F102 of 40% to 100%. Forty-two hours after operation, the band was loosened 3 mm in circumference in the intensive care unit. The
Volume 86
Extrathoracically adjustable pulmonary artery banding
Number 4 October, 1983
585
Follow-up Late death from respiratory infection 4 mo postop. 2 yr: no cyanosis. good growth 1.5 yr; band loosened 3 rnrn in circumference 42 hr postop.• moderate cyanosis. good growth I yr. 4 rno; moderate cyanosis, good growth I yr, 4 rno; band tightened twice from 8.0 to 5.0 mm and 5.0 to 4.5 mm 4 mo postop.. no cyanosis, persistent heart failure 9 rno; band loosened 2 mm in circumference 3 hr postop., no cyanosis, good growth 6 mo; band tightened from 8.6 to 6.5 mm in diameter 3 mo postop., no cyanosis. good growth 3 rno; Mustard operation and VSD closure 3 mo postop.
Pao2 improved to 39 mm Hg with an Flo2 of 38% 5 hours after the adjustment. Thereafter, she recovered uneventfully and was discharged with some degree of cyanosis and no heart failure . The band was also loosened 2 mm in circumference in the intensive care unit 3 hours after operation in another 36-day-old infant (Case 6) with double-outlet right ventricle with doubly committed VSD because of hypoxemia. The Pao2soon improved from 70 to 113 nun Hg with an Flo2 of 100%. His subsequent postoperative course was uneventful, and he was discharged in good condition. An infant (Case 5). with coarctation of the aorta, patent ductus arteriosus (PDA), TGA, and tricuspid atresia underwent repair of coarctation by the subclavian flap technique, ligation of the PDA, and pulmonary artery banding by this technique on his fourth day of life. The pulmonary artery of 10.0 nun in diameter was constricted to 8.0 mm at operation. The immediate postoperative course was uneventful, but congestive heart failure became prominent 3 months after operation. At 4 months of age the band"was tightened from 8.0 to 5.0 mm in diameter and the Pao2decreased from 47 to 39 mm Hg with an Flo2 of 100%. Since the congestive heart failure persisted, although improved, the band was tightened again to 4.5 mm in diameter 1 week later . The Pao2fell from 89 to 59 nun Hg with an Flo2 of 100%. However, further symptomatic improvement was not obtained presumably because of other associated cardiac anomalies . The band was also tightened from 8.6 to 6.5 nun in diameter 3 months after operation in a ZQ-month-old patient (Case 7) with single ventricle, TGA, and slight pulmonary stenosis because of persistent congestive
Fig. 2. The adjustable band is tightened around the pulmonary artery . Ao, Aorta . PA. Pulmonary artery .
heart failure. The failure disappeared soon after the retightening, and he was discharged in good condition. One patient (Case 8) underwent debanding of the pulmonary artery at the time of a subsequent Mustard operation and VSD closure 3 months after the initial banding. No adhesions existed around the tourniquet system, and the 3 mm and 5 mm PTFE grafts were easily movable when the tourniquet was loosened and tightened. The both PTFE grafts were soft and clean, and they did not adhere to the pulmonary artery. When the 3 mm and 5 mm grafts were removed, the pulmonary artery gained its adequate size spontaneously. One patient with polysplenia syndrome (Case 1) died at home 4 months after banding as a result of respiratory infection. Autopsy was not performed. The remaining patients received satisfactory symptomatic palliation and grew adequately, except for the one (Case 5) described earlier. Discussion Banding of the pulmonary artery was introduced in 1952 by Muller and Dammann" as a means of preventing overload of the pulmonary circuit and obstructive pulmonary vascular disease. The preferred technique for pulmonary artery banding is simply to place a constricting band around the artery and secure it to the wall of the artery to prevent migration. With this method the
586
The Journal of Thoracic and Cardiovascular Surgery
Muraoka et al.
proper degree of pulmonary artery constriction should be decided during operation and cannot be changed without repeat thoracotomy. Guides for the optimum constriction during operation have been proposed by many authors; for example, reducing the diameter of the pulmonary artery to one third' or between one third and one half' of the original size, reducing the pulmonary artery pressure to one half of the right ventricular pressure' or the systemic pressure, I reducing the mean pulmonary artery pressure from 20 to 30 mm Hg,7 and raising the systemic pressure 10 to 20 mm Hg or until the appearance of slight bradycardia." Trusler and Mustard' reported that optimum circumference of the band could be predicted from the infant's weight and cardiac malformation. The circumference presented in millimeters was 20 plus body weight (kilograms) for isolated VSD and 24 plus body weight (kilograms) for TGA with VSD. Unfortunately, results with such methods are inconsistent, especially in infants with complicated and/or cyanotic cardiac anomalies as well as in infants who are severely ill and require urgent operation. Some of them cannot accept a tight enough band because bradycardia, systemic hypotension, severe hypoxemia, and sometimes cardiac arrest may occur. For these severely ill patients, a method of banding which can be delicately adjustable not only during operation but also postoperatively was developed. Since gradual and delicate snaring and loosening of the band are possible with this method, the optimum constriction can be made safely at operation even in severely ill patients. There were no significant crises in this series during the operations. Nevertheless, the patient's hemodynamic and respiratory condition may be affected by anesthesia and thoracotomy so that the constriction made at operation may not always be optimum after operation. If such a situation occurs, the band can be adjusted via a small skin incision. Two cyanotic infants required loosening of the band to alleviate hypoxemia in the intensive care unit shortly after operation. Another two infants needed additional tightening of the band to improve congestive heart failure 3 and 4 months after operations, respectively. Each procedure was performed easily. Both postoperative loosening and tightening of the
band could be done shortly after the operation, and additional tightening at least 4 months later was also done easily. From the findings at the subsequent debanding in one patient (Case 8) 3 months after the banding procedure, we are convinced that both loosening and tightening of the band in a later postoperative period can be feasible. The results reported herein demonstrate the advantage of adjustability of this technique during and after operation, which may avoid most mortality and morbidity related to an inappropriate banding. However, more experience and further follow-up will be required to assess adjustability later than 4 months postoperatively. REFERENCES
2
3
4
5
6
7
8
Stewart S, Harris P, Manning' J: Pulmonary artery banding. An analysis of current risk, results, and indications. J TIIORAC CARDIOVASC SURG 80:431-436, 1980 McGoon DC, Danielson GK, Ritter DG, Mair DD, I1strup DM: Late results after extracardiac conduit repair for congenital cardiac defects. Am J Cardiol 49:1741-1749, 1982 Trusler GA, Mustard WT: A method of banding the pulmonary artery for large isolated ventricular septal defect with and without transposition of the great arteries. Ann Thorac Surg 13:351-355, 1972 Muller WH Jr, Dammann JF Jr: The treatment of certain congenital malformations of the heart by the creation of pulmonic stenosis to reduce pulmonary hypertension and excessive pulmonary blood flow. Surg Gynecol Obstet 95:213-219,1952 Craig TV, Sirak HD: Pulmonary artery banding. An analysis of 38 cases. J THORAC CARDIOVASC SURG 45:599604, 1963 Patel RG, Ihenacho HNC, Abrams LD, Astley R, Parsons CG, Roberts KD, Singh SP: Pulmonary artery banding and subsequent repair in ventricular septal defect. Br Heart J 35:651-656, 1973 Morrow AG, Braunwald NS: The surgical treatment of ventricular septal defect in infancy. The technic and results of pulmonary artery constriction. Circulation 24:34-40, 1961 Mahle S, Nicoloff DM, Knight L, Moller JH: Pulmonary artery banding. Long-term results in 63 patients. Ann Thorac Surg 27:216-224, 1979
THORAC CARDIOVASC SURG
86:582-586, 1983
Extrathoracically adjustable pulmonary artery banding A new technique of adjustable pulmonary artery banding is presented. A tourniquet system has been used in eight consecutive infants with complex congenital cardiac anomalies during the past 2 years. They had severe congestive heart failure, and six of them required inotropic support preoperatively. All survived the banding procedure and there were no hospital deaths. Four of the eight infants required additional adjustment of the band to improve hypoxemia or persistent congestive heart failure 3 hours to 4 months postoperatively. Each adjustment was made easily via a small skin incision without thoracotomy. This technique allows fine adjustment by gentle and delicate tightening and loosening of the band during and after operation. so that the technique avoids most mortality and morbidity related to an inappropriate banding and brings satisfactory symptomatic palliation.
Ryusuke Muraoka, M.D., Michio Yokota, M.D., Minoru Aoshima, M.D., Shinichi Nomoto, M.D., Inshin Kyoku, M.D., Akira Kobayashi, M.D., Hiroyuki Nakano, M.D., Ken Veda, M.D., and Akihiro Saito, M.D., Shizuoka, Japan
~h
improvement in operative technique, many cardiac defects can be corrected safely by a primary procedure performed in the first few years of life. However, there are some defects that are not amenable or remain controversial with respect to an early primary repair. I Banding of the pulmonary artery continues to play an important role in the management of such defects to lessen congestive heart failure, to prevent pulmonary vascular disease, and to allow survival until the infant is a suitable candidate for corrective operation. Moreover, recent progress in extra-anatomic repair of complex cardiac anomalies in later childhood- may increase the importance of this procedure. Optimum constriction may not always be possible by the conventional technique, and the degree of pulmonary artery banding once made cannot be changed after operation without thoracotomy. When the constriction is made too loose or too tight, congestive heart failure persists or severe hypoxemia appears. We developed a From the Second Department of Surgery, Fukui Medical School, Fukui, and the Departments of Cardiovascular Surgery and Cardiology, Shizuoka Children's Hospital, Shizuoka, Japan Received for publication Dec. 27, 1982. Accepted for publication Feb. 21, 1983. Address for reprints: Ryusuke Muraoka, M.D., The Second Department of Surgery, Fukui Medical School, 23 Shimoaizuki Matsuoka-cho, Yoshida-gun Fukui-ken 910-11, Japan
582
new technique for pulmonary artery banding that allows adjustment postoperatively if necessary by the use of a small skin incision but without thoracotomy. This article describes the technique and the results of our clinical application.
Patients Between October, 1980, and July, 1982, a total of eight infants with complex congenital heart diseases underwent banding of the pulmonary artery by the technique described herein at the Shizuoka Children's Hospital. Ages ranged from 4 days to 20 months (mean 6.3 ± 7.3 months) and weights between 2.9 and 9.7 kg (mean 4.6 ± 2.3 kg). Table I shows the preoperative diagnosis and other data. The operations were performed on an emergency basis in four infants. All infants had severe congestive heart failure unresponsive to medical therapy. Six of eight patients required inotropic support preoperatively. Their cardiothoracic ratios ranged from 0.62 to 0.68 (mean 0.64 ± 0.03). Two infants with complete transposition of the great arteries (TGA) and ventricular septal defect (YSD) had severe hypoxemia (partial pressure of oxygen in the systemic arterial blood [Pao2] of 41 and 40 mm Hg with the fraction of oxygen in inspired gas [F102] 100%). Both of them had undergone prior surgical creation of an atrial septal defect. The remaining six patients had no significant hypoxemia (Pao2 of 92 to 364 mm Hg with
Volume 86 Number 4 Oc tob er . 19 83
Extrathoracically adjustable pulmonary artery banding
583
Fig. 1. Device enabling extrathoracica lly adjustable pulmonary ar tery band ing. It consists of a microporous expanded polytetrafluoroeth ylene (PTFE) 3 mm graft , a long heavy monofilament nylon ligatu re, a PT FE 5 mm graft, and a narrow hard polyvinyl chloride tube. Left inset: Both ends of the 3 mm PTFE graft are inserted into the 5 mm PTFE graft before the tourniquet is tightened . R ight inset: When the tournique t is tightened, the 3 mm and 5 mm PTFE grafts make an adequate circle for pulmonary artery banding. Direct compression on the nylon ligature and the polyvinyl chloride tube to the pulmonary artery is avoided by the PTFE grafts .
Table I. Preoperative data
Case No.
Age 2 mo
2
3 4
5 6 7
8
13 rna I rna 3 mo 4 days I mo 20 mo 10 rna
Weight (kg)
4.1 4.7
2.9 3.5 2.7 3.2 9.7
5.9
Diagnosis SV, SA, PA at resia, anomalous vessel from Ao to PA, dextrocard ia, polysplenia syndrome" TGA, SV, SA, dextrocard ia TGA, VSO" TGA, VSO eoA, POA, TGA , TA" OORV (doubly committ ed VS D)" TGA , SV , PS (slight) TG A, VSD. post-ASl) creation
CT ratio
Dose of dopamine (Ilgfkgfm inj
0.66
10
0.60 0.62 0.62 0.65 0.68 0.68 0.64
10
10
7 8 6
Legend: CT . Ca rdiothoracic. SV. Single ventricle. SA . Single a trium. PA. Pulmona ry a rtery. Ao, Aorta . TG A. Complete transposition of the great a rteries. (I n the case of SV, this refers to malposition of the grea t ar tcr ies.) VSD. Ventricular septa l defect. CoA . Coarct at ion of the aorta. PDA. Pat ent ductu s a rteriosus. TA . Tr icuspid a tresia . DORV. Double-outlet right ventricle. PS. Pulmona ry stenosis. AS D. At rial septal defect. " Emergency operation .
the Fl02 100%). Four of eight infants required adjustment of the banding 3 hours to 4 months after the operations because of severe hypoxemia or persistent congestive heart failure. Operative technique The tourniquet system for the adjustable pulmonary artery banding consisted of a microporous expanded polytetrafluoroethylene WIFE) graft 3 mm in diame-
ter, a long heavy monofilament nylon ligature, a PTFE graft 5 mm in diameter, a narrow hard silicone-coated polyvinyl chloride tube, and hemoclips (Fig. 1). The 3 mm PTFE graft containing the monofilament nylon ligature was passed around the pulmonary artery. The circumference of the banding is approximately the same as the length of the 3 mm graft. However, since the graft material is compressible longitudinally, the appropriate length of the 3 mm PTFE graft was decided in advance
584
The Journal of Thoracic and Cardiovascular Surgery
Muraoka et al.
Table II. Results of the adjustable pulmonary artery banding (initial operation) Pressure (mm Hg) Diameter of PA (mm) After
Before
Case No.
Before
2.5
30
2 3
20.5 10.0
8.5
54
4
5
11.5 10.0
8.0 8.0
6
10.5
5.8
7
14.0
8.6
8
10.5
7.4
5.5*
I
Systemic systolic pressure
PA mean pressure
I
After
Before
20
84 72 80
32
8.2
39
I
After
Pao} (mm Hg) with Flo} 1.0
Before
I
After
97
57
107
364 41
39 139 25
110
93 52
126
70
40 244
130
22
68
79
340
79
37
27
77
73
207
93
29
25
92
93
92
67
45
43
Legend: PA. Pulmonary artery.
*Anomalous
vessel from the aorta to the pulmonary artery.
by snaring the graft around a Hegar cervical dilator of a diameter equal to that intended for the banded site. The length of the 3 mm graft in this series was from 55 to 75 mm according to the size of the infant and the defect, which allowed the banding to be approximately 20% tighter than that proposed by Trusler and Mustard.' Each end of the nylon ligature was passed through the respective end of a small length (15 to 30 mm) of the 5 mm in diameter PTFE graft and was then passed through a hole prepared in the middle of the 5 mm PTFE graft. Both ends of the nylon ligature were then passed through a polyvinyl chloride tube (7 to 14 em in length) which was prepared from an arterial pressuremonitoring tube. The pulmonary artery was then constricted gradually while systemic and pulmonary arterial pressures, heart rates, and systemic Paoz were being monitored. When the nylon ligature was tightened, the 5 mm graft enclosed each end of the 3 mm graft as a sheath and prevented the direct compression of the nylon ligature on the pulmonary artery (Fig. 2). The approximate size of the constricted pulmonary artery was calculated from the length of the nylon ligature outside the tube and was measured directly by twodimensional echocardiography during the operation. After proper constriction was established, multiple hemoclips were placed firmly around the end of the tube furthest from the pulmonary artery to keep the nylon ligature from slipping within it. The end of the tube with its hemoclips was withdrawn to the level of the anterior chest wall and was buried under the muscular layer. When postoperative adjustment of the tightness of the band was indicated, a small skin incision was made and
the band was readjusted simply by relocating the hemoclips.
Results All eight infants survived the banding procedure, and there were no hospital deaths. Fine and gradual constriction of the pulmonary artery could be done by this method without hemodynamic deterioration even in severely ill infants. The pulmonary artery was constricted to an average of 7.1 ± 2.2 mm in diameter, and mean pressure of the pulmonary artery fell to 29 ± 9 mm Hg. Systemic arterial pressure rose and systemic Paoz fell. Table II shows the data before and after the banding procedure. Postoperative adjustment of the banding was necessitated in four patients; loosening in two to improve hypoxemia and tightening in two to improve persistent congestive heart failure (Table 11). A 55-day-old infant (Case 3) with TGA and VSD had severe hypoxemia and congestive heart failure. Preoperative cardiac catheterization revealed an extremely low POz of the pulmonary vein (36 mm Hg with an Floz of 21%) and of the aorta (29 mm Hg with an F10z of 21%) with a large interatrial communication that had been made by prior balloon atrial septostomy. Therefore, pulmonary artery banding was indicated to improve congestive heart failure as well as hypoxemia. The pulmonary artery of 10.0 mm in diameter was constricted to 8.2 mm in the operating room. Postoperatively, the Paoz persisted below 30 mm Hg with an F102 of 40% to 100%. Forty-two hours after operation, the band was loosened 3 mm in circumference in the intensive care unit. The
Volume 86
Extrathoracically adjustable pulmonary artery banding
Number 4 October, 1983
585
Follow-up Late death from respiratory infection 4 mo postop. 2 yr: no cyanosis. good growth 1.5 yr; band loosened 3 rnrn in circumference 42 hr postop.• moderate cyanosis. good growth I yr. 4 rno; moderate cyanosis, good growth I yr, 4 rno; band tightened twice from 8.0 to 5.0 mm and 5.0 to 4.5 mm 4 mo postop.. no cyanosis, persistent heart failure 9 rno; band loosened 2 mm in circumference 3 hr postop., no cyanosis, good growth 6 mo; band tightened from 8.6 to 6.5 mm in diameter 3 mo postop., no cyanosis. good growth 3 rno; Mustard operation and VSD closure 3 mo postop.
Pao2 improved to 39 mm Hg with an Flo2 of 38% 5 hours after the adjustment. Thereafter, she recovered uneventfully and was discharged with some degree of cyanosis and no heart failure . The band was also loosened 2 mm in circumference in the intensive care unit 3 hours after operation in another 36-day-old infant (Case 6) with double-outlet right ventricle with doubly committed VSD because of hypoxemia. The Pao2soon improved from 70 to 113 nun Hg with an Flo2 of 100%. His subsequent postoperative course was uneventful, and he was discharged in good condition. An infant (Case 5). with coarctation of the aorta, patent ductus arteriosus (PDA), TGA, and tricuspid atresia underwent repair of coarctation by the subclavian flap technique, ligation of the PDA, and pulmonary artery banding by this technique on his fourth day of life. The pulmonary artery of 10.0 nun in diameter was constricted to 8.0 mm at operation. The immediate postoperative course was uneventful, but congestive heart failure became prominent 3 months after operation. At 4 months of age the band"was tightened from 8.0 to 5.0 mm in diameter and the Pao2decreased from 47 to 39 mm Hg with an Flo2 of 100%. Since the congestive heart failure persisted, although improved, the band was tightened again to 4.5 mm in diameter 1 week later . The Pao2fell from 89 to 59 nun Hg with an Flo2 of 100%. However, further symptomatic improvement was not obtained presumably because of other associated cardiac anomalies . The band was also tightened from 8.6 to 6.5 nun in diameter 3 months after operation in a ZQ-month-old patient (Case 7) with single ventricle, TGA, and slight pulmonary stenosis because of persistent congestive
Fig. 2. The adjustable band is tightened around the pulmonary artery . Ao, Aorta . PA. Pulmonary artery .
heart failure. The failure disappeared soon after the retightening, and he was discharged in good condition. One patient (Case 8) underwent debanding of the pulmonary artery at the time of a subsequent Mustard operation and VSD closure 3 months after the initial banding. No adhesions existed around the tourniquet system, and the 3 mm and 5 mm PTFE grafts were easily movable when the tourniquet was loosened and tightened. The both PTFE grafts were soft and clean, and they did not adhere to the pulmonary artery. When the 3 mm and 5 mm grafts were removed, the pulmonary artery gained its adequate size spontaneously. One patient with polysplenia syndrome (Case 1) died at home 4 months after banding as a result of respiratory infection. Autopsy was not performed. The remaining patients received satisfactory symptomatic palliation and grew adequately, except for the one (Case 5) described earlier. Discussion Banding of the pulmonary artery was introduced in 1952 by Muller and Dammann" as a means of preventing overload of the pulmonary circuit and obstructive pulmonary vascular disease. The preferred technique for pulmonary artery banding is simply to place a constricting band around the artery and secure it to the wall of the artery to prevent migration. With this method the
586
The Journal of Thoracic and Cardiovascular Surgery
Muraoka et al.
proper degree of pulmonary artery constriction should be decided during operation and cannot be changed without repeat thoracotomy. Guides for the optimum constriction during operation have been proposed by many authors; for example, reducing the diameter of the pulmonary artery to one third' or between one third and one half' of the original size, reducing the pulmonary artery pressure to one half of the right ventricular pressure' or the systemic pressure, I reducing the mean pulmonary artery pressure from 20 to 30 mm Hg,7 and raising the systemic pressure 10 to 20 mm Hg or until the appearance of slight bradycardia." Trusler and Mustard' reported that optimum circumference of the band could be predicted from the infant's weight and cardiac malformation. The circumference presented in millimeters was 20 plus body weight (kilograms) for isolated VSD and 24 plus body weight (kilograms) for TGA with VSD. Unfortunately, results with such methods are inconsistent, especially in infants with complicated and/or cyanotic cardiac anomalies as well as in infants who are severely ill and require urgent operation. Some of them cannot accept a tight enough band because bradycardia, systemic hypotension, severe hypoxemia, and sometimes cardiac arrest may occur. For these severely ill patients, a method of banding which can be delicately adjustable not only during operation but also postoperatively was developed. Since gradual and delicate snaring and loosening of the band are possible with this method, the optimum constriction can be made safely at operation even in severely ill patients. There were no significant crises in this series during the operations. Nevertheless, the patient's hemodynamic and respiratory condition may be affected by anesthesia and thoracotomy so that the constriction made at operation may not always be optimum after operation. If such a situation occurs, the band can be adjusted via a small skin incision. Two cyanotic infants required loosening of the band to alleviate hypoxemia in the intensive care unit shortly after operation. Another two infants needed additional tightening of the band to improve congestive heart failure 3 and 4 months after operations, respectively. Each procedure was performed easily. Both postoperative loosening and tightening of the
band could be done shortly after the operation, and additional tightening at least 4 months later was also done easily. From the findings at the subsequent debanding in one patient (Case 8) 3 months after the banding procedure, we are convinced that both loosening and tightening of the band in a later postoperative period can be feasible. The results reported herein demonstrate the advantage of adjustability of this technique during and after operation, which may avoid most mortality and morbidity related to an inappropriate banding. However, more experience and further follow-up will be required to assess adjustability later than 4 months postoperatively. REFERENCES
2
3
4
5
6
7
8
Stewart S, Harris P, Manning' J: Pulmonary artery banding. An analysis of current risk, results, and indications. J TIIORAC CARDIOVASC SURG 80:431-436, 1980 McGoon DC, Danielson GK, Ritter DG, Mair DD, I1strup DM: Late results after extracardiac conduit repair for congenital cardiac defects. Am J Cardiol 49:1741-1749, 1982 Trusler GA, Mustard WT: A method of banding the pulmonary artery for large isolated ventricular septal defect with and without transposition of the great arteries. Ann Thorac Surg 13:351-355, 1972 Muller WH Jr, Dammann JF Jr: The treatment of certain congenital malformations of the heart by the creation of pulmonic stenosis to reduce pulmonary hypertension and excessive pulmonary blood flow. Surg Gynecol Obstet 95:213-219,1952 Craig TV, Sirak HD: Pulmonary artery banding. An analysis of 38 cases. J THORAC CARDIOVASC SURG 45:599604, 1963 Patel RG, Ihenacho HNC, Abrams LD, Astley R, Parsons CG, Roberts KD, Singh SP: Pulmonary artery banding and subsequent repair in ventricular septal defect. Br Heart J 35:651-656, 1973 Morrow AG, Braunwald NS: The surgical treatment of ventricular septal defect in infancy. The technic and results of pulmonary artery constriction. Circulation 24:34-40, 1961 Mahle S, Nicoloff DM, Knight L, Moller JH: Pulmonary artery banding. Long-term results in 63 patients. Ann Thorac Surg 27:216-224, 1979