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An Improved Method of Pulmonary Artery Banding
HOW TO DO IT
An Improved Method of Pulmonary Artery Banding Himmet Dajee, M.D., Lee Benson, M.D., F.R.C.P.(C), and Hillel Laks, M.D. ABSTRACT Banding of the pulmonary artery is a difficult procedure that often requires band readjustment. A new technique for placing and adjusting pulmonary artery bands using an adjustable snare is presented, together with cases illustrating its application. Banding of the pulmonary arteries has proved to be a useful palliative procedure in children with congenital cardiac lesions associated with excessive pulmonary blood flow and pulmonary hypertension secondary to a nonrestrictive ventricular septal defect [l]. At present, there is considerable opinion that banding for an isolated ventricular defect is obsolete [2]. Certain complex congenital cardiac malformations, however, such as univentricular heart, truncus arteriosus type II/III, and multiple muscular septal defects, do not lend themselves to primary repair in early infancy [3]. In these circumstances, banding of the pulmonary artery (PA) may provide effective palliation. Initial mortality often results from either an inadequate band or profound reduction in pulmonary flow and resultant hypoxemia [4]. Various approaches have been applied to calculate the appropriate band diameter [5], but once the band has been placed, it is difficult to readjust it. Presented here is a new technique for applying PA bands that allows for rapid and easy adjustment both in the operating room and at the bedside.
Technique The PA is exposed through a left anterior thoracotomy. In female patients a submammary incision is used, while in male patients the incision is made above the nipple over the second interspace. The pericardium is opened longitudinally anterior to the phrenic nerve. A 5-0 silk braid is marked with the estimated circumference of the band using the formula proposed by Trusler and Mustard (51 and also judging from its appearance on the angiogram. For normally related great vessels, the length of the band in millimeters is 20 plus the weight in kilograms. For transposition of the great arteries, the band length in millimeters is 24 plus the weight in kilograms. Two 5-0 Ethibond sutures are used to mark the appropriate distance on the silk braid. The aorta is dissected away from the main PA, keeping close to the aorta at the base of the main PA to avoid obstruction to the rigtt PA by the band. A right-angle clamp is passed
From the Departments of Cardiovascular Surgery and Pediatric Cardiology, UCLA Medical Center, Los Angeles, CA. Accepted for publication May 24, 1983. Address reprint requests to Dr. Laks, Division of Cardiothoradc Surgery, UCLA Medical Center, Los Angeles, CA 90024.
254
around the aorta, and the silk braid is pulled through. The right-angle clamp is then passed around the aorta and the PA through the transverse sinus, and the silk braid is brought around the PA (Fig 1).The ends of the silk braid are passed through a 2 cm length of polyethylene tubing (Pharmaseal8F infant suction catheter), and the PA is constricted using the snare approximating the previously placed markers on the silk braid. The distal PA and systemic arterial pressures are monitored continuously. A suitable band is usually indicated by a 15 mm Hg rise in the systemic arterial pressure, a fall in the distal PA pressure to about half the systemic pressure, a reduction in PA diameter by about 50%, and the presence of a prominent thrill over the PA. If bradycardia occurs, the band is released. After a period of stabilization, an arterial oxygen saturation value is obtained. On 100% oxygen, a saturation of about 87% is considered appropriate. The snare then is fixed, using medium hemoclips on the silk braid flush with the polyethylene tube and on the polyethylene itself. The band is sutured to the PA to avoid distal migration, the snare is placed within the pericardium or in the subcutaneous space, and the edges are approximated with interrupted sutures. Case Reports Patient I A male infant weighed 3.8 kg at birth following a fullterm pregnancy and normal delivery. Cardiac evaluation was obtained at 2 days of age for persistent cyanosis. Catheterization documented a double-outlet right ventricle with dextro(D)-malposition of the great arteries, subpulmonary ventricular septal defect, patent ductus arteriosus, and mitral valve override. Over a threemonth period, congestive heart failure increased despite anticongestive medications. Since complete repair was not deemed advisable at this age, palliative PA banding and ductal ligation were performed. Through a left anterior thoracotomy in the second intercostal space, the pericardium was opened, the ductus was ligated with 2-0 silk braid, and the posterior main pulmonary trunk was isolated. Number 5-0 Ethibond sutures were placed 26 mm apart on a 5-0 silk braid. Figure 2 illustrates intraoperative pressure changes comparing the radial and distal main PA. Initially the PA pressure was 60 mm Hg and the radial pressure was 40 mm Hg; with a reduction in luminal diameter the PA pressure fell to 22 mm Hg and systemic pressure increased to 82 mm H g (Fig 2B, C). At 100% oxygen intake, arterial saturation was 94%at first, then fell to 80% with band snaring. The child showed immediate clinical improvement, was extubated the next day, and maintained an arterial oxygen saturation of 80% in room air.
255 How to Do It: Dajee, Benson, and Laks: Pulmonary Artery Banding
A
B
C D Fig 1. Technique of pulmonary artery banding: (A) The right-angle clamp is passed around the aorta, and the silk braid is pulled through. ( B ) The clamp is passed through the transverse sinus, and the silk braid is grasped behind the aorta. (C) The clamp is withdrawn, and the braid is brought around the pulmonary artery. (D)The braid is passed through the polyethylene catheter, tension is applied so that the premarked Ethibond sutures oppose one another, and hemoclips are placed to maintain tension.
256 The Annals of Thoracic Surgery Vol 37 No 3 March 1984
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A B C Fig 2 . Changes in radial (RA)and distal main pulmonary artery (PA) pressures intraoperatively (A) prior to and (B, C ) during reduction in pulmonary artery diameter.
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Patient 2 A 3.4 kg male infant was born at term to a 31-year-old woman (gravida 3, para 2) by a repeat cesarean section. Apgar score was 8 at one minute and 7 at five minutes because of duskiness and bradycardia related to amniotic fluid aspiration. Persistent cyanosis after intubation resulted in cardiac evaluation; the clinical and echocardiographic diagnoses of truncus arteriosus, interrupted aortic arch, and patent ductus arteriosus were confirmed at cardiac catheterization. Complete repair was considered inadvisable, and repair of the interrupted aortic arch and bilateral PA bandings were performed as initial palliation at 48 hours of age. A left thoracotomy incision was made in the third intercostal space. The pericardium was opened, and a large patent ductus arteriosus was isolated, as were the truncus and both PAS, which arose posteriorly. A type B arch interruption distal to the left carotid of 3 to 4 cm was identified, and the descending aorta was dissected out. The patient was heparinized and sidebiting clamps were applied, allowing a 6 mm Gore-Tex graft to be anastomosed between the left carotid and the descending aorta just distal to the left subclavian artery. The patent ductus arteriosus was then ligated with 2-0 silk braid. On 5-0 silk braid, 5-0 Ethibond sutures were placed 9 mm apart. The PAS were dissected free, and the premeasured and marked 5-0 silk braids were passed around each branch. The PAS then were snared with a polyethylene catheter until the Ethibond sutures approximated one another, and a hemoclip was applied to the silk braids as they emerged from the catheter. By varying the tension on the silk braids with the hemoclips, the oxygen saturation was adjusted to 90% while the patient breathed 100% oxygen. Forty-five minutes after the child had arrived in the intensive care unit, the blood oxygen tension fell from 32 to 13mm Hg (Fig 3). A chest roentgenogram did not suggest a compromising pneumothorax, and the chest was reopened at the bedside. The tension of the braids was readjusted by placing hemoclips above the previous clips and removing the lower clips, enlarging the diameter of the bands until the saturation was 85% (arterial oxygen tension H PO^], 49
Fig 3. Representative systemic arterial oxygen tension (A) prior to banding; (B)immediately afrer banding; (C, D)in the operating r w m (or);and (E) in the intensive care unit (icu), where oxygen tension fell and (F) was restabilized by bedside band adjustment.
mm Hg) on 100%oxygen. The chest was reclosed. The child was extubated on the sixth postoperative day with a Po2 of 46 mm Hg and oxygen saturation of 86% in room air. The patient was discharged on the fifteenth hospital day. In this patient, it was possible to band both PAS from the right chest. By placing traction on the aorta and truncus anteriorly, the right PA could be snared from behind the truncus. Each PA was then banded as described.
Comment In 1952, Muller and Dammann [l] described the concept of constriction of the PA to palliate congenital malformations with unrestricted left-to-right shunts. Initial experience has shown the effectiveness of this form of therapy [6]. However, with the improved mortality figures for primary repair, especially for isolated ventricular septa1 defects (41 and even more complex lesions (31, the cumulative mortality of a two-staged procedure and the complications of PA banding have induced many centers to abandon this procedure. Nevertheless, PA banding remains a valuable tool, allowing palliative intervention for those complex lesions not amenable to primary repair in infancy (71. Survival data from several series vary from 5 to 26%, with complex lesions showing a mortality in excess of 50%after banding in the first four months (3, 41. The postoperative course vanes from uneventful to extremely difficult, often requiring prolonged intubation because of excessive pulmonary blood flow. The most difficult and yet most critical aspect of the procedure is the appropriate adjustment of the band. Pressure measurements alone [8] have not proved effective in evaluating the adequacy of the band. Levitsky and associates [9] have advocated reducing arterial saturation to between 87 and 92% in 100% oxygen. Trusler and Mustard [5] relate the circumference of the band to the patient's
257 How to Do It: Dajee, Benson, and Laks: Pulmonary Artery Banding
weight. Despite these aids, application of pulmonary artery bands is still imprecise and penoperative mortality remains substantial. The technique described here has the advantage of allowing an initial estimation of the reduction in PA diameter and facilitates rapid adjustments in the constriction of the pulmonary artery in the operating room. Moreover, the position of the snare permits adjustment without need for dissecting the pulmonary trunk and removing and reapplying the band. Furthermore, as exemplified by Patient 2, bedside adjustment may allow lifesaving alterations in pulmonary blood flow. The long-term results of this procedure are not known. At present we use the snare in those patients for whom we plan a definitive repair within one or two years. The band could be left in the subcutaneous space for further adjustment without a thoracotomy.
References 1. Muller WH Jr, Dammann JF Jr: Treatment of certain congenital malformations by creation of pulmonic stenosis to reduce pulmonary hypertension and excessive pulmonary blood Bow: preliminary report. Surg Gynecol Obstet 95:215, 1952
2. Griepp E, French JW, Shumway N, Baum D Is pulmonary artery banding for ventricular septal defects obsolete?Circulation 49Suppl214, 1974 3. Stewart S, Hams P, Manning J: Pulmonary artery banding: an analysis of current risks, results, and indications. J Thorac Cardiovasc Surg 80:431, 1980 4. Kirklin JW, Appelbaum A, Bargeron LM Jr: Primary repair versus banding for ventricular septal defect in infancy. In Kidd BSL, Rowe RD (eds):The Child with Congenital Heart Disease after Surgery. Mt. Kisco, NY, Futura, 1976, pp 3-9 5. Trusler GA, Mustard WT:A method of banding the pulmonary artery for large isolated ventricular septal defects with and without transposition of the great arteries. Ann Thorac Surg 13:351, 1972 6. Girod DA, Hurwitz RA, King H, Jolly W: Recent results of two-stage surgical treatment of large ventricular septal defect. Circulation 49:Suppl 2:9, 1974 7. Doty BD Pulmonary artery banding. In Glenn WWL, Baue AE, Geha AS, et a1 (eds): Thoracic and Cardiovascular Surgery. Fourth edition. New York, Appleton-CenturyCrofts, 1983, pp 681-687 8. Utley J R Hemodynamic observations during and after pulmonary artery banding. Ann Thorac Surg 15493, 1973 9. Levitsky S, DuBrow IW, Hastreiter AR: Pulmonary artery banding in infants: a physiological intraoperative method of determining the effectivenessof the procedure. Ann Thorac Surg 17492, 1974
An Improved Method of Pulmonary Artery Banding Himmet Dajee, M.D., Lee Benson, M.D., F.R.C.P.(C), and Hillel Laks, M.D. ABSTRACT Banding of the pulmonary artery is a difficult procedure that often requires band readjustment. A new technique for placing and adjusting pulmonary artery bands using an adjustable snare is presented, together with cases illustrating its application. Banding of the pulmonary arteries has proved to be a useful palliative procedure in children with congenital cardiac lesions associated with excessive pulmonary blood flow and pulmonary hypertension secondary to a nonrestrictive ventricular septal defect [l]. At present, there is considerable opinion that banding for an isolated ventricular defect is obsolete [2]. Certain complex congenital cardiac malformations, however, such as univentricular heart, truncus arteriosus type II/III, and multiple muscular septal defects, do not lend themselves to primary repair in early infancy [3]. In these circumstances, banding of the pulmonary artery (PA) may provide effective palliation. Initial mortality often results from either an inadequate band or profound reduction in pulmonary flow and resultant hypoxemia [4]. Various approaches have been applied to calculate the appropriate band diameter [5], but once the band has been placed, it is difficult to readjust it. Presented here is a new technique for applying PA bands that allows for rapid and easy adjustment both in the operating room and at the bedside.
Technique The PA is exposed through a left anterior thoracotomy. In female patients a submammary incision is used, while in male patients the incision is made above the nipple over the second interspace. The pericardium is opened longitudinally anterior to the phrenic nerve. A 5-0 silk braid is marked with the estimated circumference of the band using the formula proposed by Trusler and Mustard (51 and also judging from its appearance on the angiogram. For normally related great vessels, the length of the band in millimeters is 20 plus the weight in kilograms. For transposition of the great arteries, the band length in millimeters is 24 plus the weight in kilograms. Two 5-0 Ethibond sutures are used to mark the appropriate distance on the silk braid. The aorta is dissected away from the main PA, keeping close to the aorta at the base of the main PA to avoid obstruction to the rigtt PA by the band. A right-angle clamp is passed
From the Departments of Cardiovascular Surgery and Pediatric Cardiology, UCLA Medical Center, Los Angeles, CA. Accepted for publication May 24, 1983. Address reprint requests to Dr. Laks, Division of Cardiothoradc Surgery, UCLA Medical Center, Los Angeles, CA 90024.
254
around the aorta, and the silk braid is pulled through. The right-angle clamp is then passed around the aorta and the PA through the transverse sinus, and the silk braid is brought around the PA (Fig 1).The ends of the silk braid are passed through a 2 cm length of polyethylene tubing (Pharmaseal8F infant suction catheter), and the PA is constricted using the snare approximating the previously placed markers on the silk braid. The distal PA and systemic arterial pressures are monitored continuously. A suitable band is usually indicated by a 15 mm Hg rise in the systemic arterial pressure, a fall in the distal PA pressure to about half the systemic pressure, a reduction in PA diameter by about 50%, and the presence of a prominent thrill over the PA. If bradycardia occurs, the band is released. After a period of stabilization, an arterial oxygen saturation value is obtained. On 100% oxygen, a saturation of about 87% is considered appropriate. The snare then is fixed, using medium hemoclips on the silk braid flush with the polyethylene tube and on the polyethylene itself. The band is sutured to the PA to avoid distal migration, the snare is placed within the pericardium or in the subcutaneous space, and the edges are approximated with interrupted sutures. Case Reports Patient I A male infant weighed 3.8 kg at birth following a fullterm pregnancy and normal delivery. Cardiac evaluation was obtained at 2 days of age for persistent cyanosis. Catheterization documented a double-outlet right ventricle with dextro(D)-malposition of the great arteries, subpulmonary ventricular septal defect, patent ductus arteriosus, and mitral valve override. Over a threemonth period, congestive heart failure increased despite anticongestive medications. Since complete repair was not deemed advisable at this age, palliative PA banding and ductal ligation were performed. Through a left anterior thoracotomy in the second intercostal space, the pericardium was opened, the ductus was ligated with 2-0 silk braid, and the posterior main pulmonary trunk was isolated. Number 5-0 Ethibond sutures were placed 26 mm apart on a 5-0 silk braid. Figure 2 illustrates intraoperative pressure changes comparing the radial and distal main PA. Initially the PA pressure was 60 mm Hg and the radial pressure was 40 mm Hg; with a reduction in luminal diameter the PA pressure fell to 22 mm Hg and systemic pressure increased to 82 mm H g (Fig 2B, C). At 100% oxygen intake, arterial saturation was 94%at first, then fell to 80% with band snaring. The child showed immediate clinical improvement, was extubated the next day, and maintained an arterial oxygen saturation of 80% in room air.
255 How to Do It: Dajee, Benson, and Laks: Pulmonary Artery Banding
A
B
C D Fig 1. Technique of pulmonary artery banding: (A) The right-angle clamp is passed around the aorta, and the silk braid is pulled through. ( B ) The clamp is passed through the transverse sinus, and the silk braid is grasped behind the aorta. (C) The clamp is withdrawn, and the braid is brought around the pulmonary artery. (D)The braid is passed through the polyethylene catheter, tension is applied so that the premarked Ethibond sutures oppose one another, and hemoclips are placed to maintain tension.
256 The Annals of Thoracic Surgery Vol 37 No 3 March 1984
..-
A B C Fig 2 . Changes in radial (RA)and distal main pulmonary artery (PA) pressures intraoperatively (A) prior to and (B, C ) during reduction in pulmonary artery diameter.
\
I
I
\
I
t
time
Patient 2 A 3.4 kg male infant was born at term to a 31-year-old woman (gravida 3, para 2) by a repeat cesarean section. Apgar score was 8 at one minute and 7 at five minutes because of duskiness and bradycardia related to amniotic fluid aspiration. Persistent cyanosis after intubation resulted in cardiac evaluation; the clinical and echocardiographic diagnoses of truncus arteriosus, interrupted aortic arch, and patent ductus arteriosus were confirmed at cardiac catheterization. Complete repair was considered inadvisable, and repair of the interrupted aortic arch and bilateral PA bandings were performed as initial palliation at 48 hours of age. A left thoracotomy incision was made in the third intercostal space. The pericardium was opened, and a large patent ductus arteriosus was isolated, as were the truncus and both PAS, which arose posteriorly. A type B arch interruption distal to the left carotid of 3 to 4 cm was identified, and the descending aorta was dissected out. The patient was heparinized and sidebiting clamps were applied, allowing a 6 mm Gore-Tex graft to be anastomosed between the left carotid and the descending aorta just distal to the left subclavian artery. The patent ductus arteriosus was then ligated with 2-0 silk braid. On 5-0 silk braid, 5-0 Ethibond sutures were placed 9 mm apart. The PAS were dissected free, and the premeasured and marked 5-0 silk braids were passed around each branch. The PAS then were snared with a polyethylene catheter until the Ethibond sutures approximated one another, and a hemoclip was applied to the silk braids as they emerged from the catheter. By varying the tension on the silk braids with the hemoclips, the oxygen saturation was adjusted to 90% while the patient breathed 100% oxygen. Forty-five minutes after the child had arrived in the intensive care unit, the blood oxygen tension fell from 32 to 13mm Hg (Fig 3). A chest roentgenogram did not suggest a compromising pneumothorax, and the chest was reopened at the bedside. The tension of the braids was readjusted by placing hemoclips above the previous clips and removing the lower clips, enlarging the diameter of the bands until the saturation was 85% (arterial oxygen tension H PO^], 49
Fig 3. Representative systemic arterial oxygen tension (A) prior to banding; (B)immediately afrer banding; (C, D)in the operating r w m (or);and (E) in the intensive care unit (icu), where oxygen tension fell and (F) was restabilized by bedside band adjustment.
mm Hg) on 100%oxygen. The chest was reclosed. The child was extubated on the sixth postoperative day with a Po2 of 46 mm Hg and oxygen saturation of 86% in room air. The patient was discharged on the fifteenth hospital day. In this patient, it was possible to band both PAS from the right chest. By placing traction on the aorta and truncus anteriorly, the right PA could be snared from behind the truncus. Each PA was then banded as described.
Comment In 1952, Muller and Dammann [l] described the concept of constriction of the PA to palliate congenital malformations with unrestricted left-to-right shunts. Initial experience has shown the effectiveness of this form of therapy [6]. However, with the improved mortality figures for primary repair, especially for isolated ventricular septa1 defects (41 and even more complex lesions (31, the cumulative mortality of a two-staged procedure and the complications of PA banding have induced many centers to abandon this procedure. Nevertheless, PA banding remains a valuable tool, allowing palliative intervention for those complex lesions not amenable to primary repair in infancy (71. Survival data from several series vary from 5 to 26%, with complex lesions showing a mortality in excess of 50%after banding in the first four months (3, 41. The postoperative course vanes from uneventful to extremely difficult, often requiring prolonged intubation because of excessive pulmonary blood flow. The most difficult and yet most critical aspect of the procedure is the appropriate adjustment of the band. Pressure measurements alone [8] have not proved effective in evaluating the adequacy of the band. Levitsky and associates [9] have advocated reducing arterial saturation to between 87 and 92% in 100% oxygen. Trusler and Mustard [5] relate the circumference of the band to the patient's
257 How to Do It: Dajee, Benson, and Laks: Pulmonary Artery Banding
weight. Despite these aids, application of pulmonary artery bands is still imprecise and penoperative mortality remains substantial. The technique described here has the advantage of allowing an initial estimation of the reduction in PA diameter and facilitates rapid adjustments in the constriction of the pulmonary artery in the operating room. Moreover, the position of the snare permits adjustment without need for dissecting the pulmonary trunk and removing and reapplying the band. Furthermore, as exemplified by Patient 2, bedside adjustment may allow lifesaving alterations in pulmonary blood flow. The long-term results of this procedure are not known. At present we use the snare in those patients for whom we plan a definitive repair within one or two years. The band could be left in the subcutaneous space for further adjustment without a thoracotomy.
References 1. Muller WH Jr, Dammann JF Jr: Treatment of certain congenital malformations by creation of pulmonic stenosis to reduce pulmonary hypertension and excessive pulmonary blood Bow: preliminary report. Surg Gynecol Obstet 95:215, 1952
2. Griepp E, French JW, Shumway N, Baum D Is pulmonary artery banding for ventricular septal defects obsolete?Circulation 49Suppl214, 1974 3. Stewart S, Hams P, Manning J: Pulmonary artery banding: an analysis of current risks, results, and indications. J Thorac Cardiovasc Surg 80:431, 1980 4. Kirklin JW, Appelbaum A, Bargeron LM Jr: Primary repair versus banding for ventricular septal defect in infancy. In Kidd BSL, Rowe RD (eds):The Child with Congenital Heart Disease after Surgery. Mt. Kisco, NY, Futura, 1976, pp 3-9 5. Trusler GA, Mustard WT:A method of banding the pulmonary artery for large isolated ventricular septal defects with and without transposition of the great arteries. Ann Thorac Surg 13:351, 1972 6. Girod DA, Hurwitz RA, King H, Jolly W: Recent results of two-stage surgical treatment of large ventricular septal defect. Circulation 49:Suppl 2:9, 1974 7. Doty BD Pulmonary artery banding. In Glenn WWL, Baue AE, Geha AS, et a1 (eds): Thoracic and Cardiovascular Surgery. Fourth edition. New York, Appleton-CenturyCrofts, 1983, pp 681-687 8. Utley J R Hemodynamic observations during and after pulmonary artery banding. Ann Thorac Surg 15493, 1973 9. Levitsky S, DuBrow IW, Hastreiter AR: Pulmonary artery banding in infants: a physiological intraoperative method of determining the effectivenessof the procedure. Ann Thorac Surg 17492, 1974