PEDIATRIC SURGEONS’ WORKSHOP
Ventriculoatrial
Shunt Utilizing
By S. Frank Redo, Armann
Ciccarelli,
Jamshid
the Azygos Vein Ghajar, and Miles Dinner
New York, New York l Long-term ventricular cerebrospinal fluid shunting prove difficult in the neonatal population, particularly those neonates who have had previous abdominal vascular procedures. This article presents a technique providing vascular access for ventriculoatrial shunting the azygos vein for patients with limited vascular access in whom ventriculoperitoneal shunting is not feasible. Copyright o 7992 by W. 8. Saunders Company
can in and of via and
INDEX WORDS: Vascular access, azygos vein; hydrocephalus; ventriculoatrial shunt; ventriculoperitoneal shunt.
NTRICULOPERITONEAL shunts have been the preferred procedure for decompression in patients with hydrocephalus. However, there are some infants who, because of previous shunt revisions, infections, abdominal operations, and many central venous line placements for long-term parenteral nutritional support, have severely limited options for placement of the distal end of cerebrospinal fluid (CSF) shunt catheters. The following case report presents an alternate method of vascular access for CSF shunting in an infant with a complex surgical history and multiple prior abdominal and vascular operations.
v”
CASE REPORT A 14-month-old boy, the product of a 27-week gestation. had postnatal problems including bronchopulmonary dysplasia, patent ductus arteriosus, and bilateral hydrocephalus. Early operative procedures included ligation of the patent ductus and bilateral ventriculoperitoneal shunts. Complications of the ventriculoperitoneal shunts included shunt infections, hernia formation, abdominal cyst and abdominal abscess formation and enterocutaneous fistula. In conjunction to these complications the patient underwent multiple revisions of the CSF shunts. Long-term parenteral nutritional support was required by way of in-dwelling central venous lines. Multiple revisions of these lines were done due to infection, thrombosis, and dislodgement. After a long and difficult hospital course exceeding 12 months. the patient had improved to the point at which he was tolerating enteral feedings and was sepsis free. At this point he required only
From the Divisions of Pediatric Surgery and Neurosurgery, Department of Surgery, and the Department of Anesthesiology, New York Hospital-Cornell Medical Center, New York, NY Date accepted: November 1, 1991. Address reprint requests to S. Frank Redo, MD, Chief; Division of Pediatric Surgery, Room N-723, New York Hospital-Cornell Medical Center, 525 E 68th St, New York, NYlOO21. Copyright 0 1992 by W.B. Saunders Company 0022-3468/9212705-0027$03.0010 642
final internalization of his ventriculoperitoneal shunt, which had been externalized following prior formation of an intraabdominal abscess. Because of the multiple problems with ventriculoperitoneal shunts already encountered in this patient, it was elected to internalize this shunt into the central venous system. Magnetic resonance imaging and ultrasound Doppler studies were performed. These documented persistent inferior vena cava thrombosis and thrombosis and occlusion of the internal and external jugular venous systems bilaterally. Therefore, options for shunt placement into the central venous system were severely restricted as would be future shunt revisions. Given the need for long-term shunt placement, a growing child, and the need to avoid distal shunt revision, it was elected to attempt internalization of the shunt into the right atrium via the azygos vein with plans to leave redundant catheter in the right hemithorax to allow future growth of the infant without the need for future shunt lengthening procedures.
Operative Procedure A right lateral thoracotomy was done through the fourth intercostal space. Multiple adhesions in the right hemithorax (the result of prior closed tube thoracostomy) were taken down and the right lung was retracted medially. The posterior pleura was incised thereby exposing the superior aspect of the azygos vein (Fig 1). Proximal and distal control of the vein was obtained and superior venous tributaries were ligated. A 30-cm length of 0.25-cm diameter silastic catheter was filled with normal saline and connected to an electrocardiograph monitor via a sterile electrical lead. This provided continuous monitoring of the catheter position. A small venotomy was made in the arch of the azygos vein and with manual compression of the superior vena cava above the azygos-superior vena cava junction, the catheter was directed into the right atrium. Final positioning was confirmed by P wave inversion on the monitoring electrocardiogram indicating suprasinoatrial node placement. To accommodate the future growth of the infant and to avoid the need for catheter lengthening procedures, a 30-cm coil of redundant catheter was placed into the right hemithorax. Intraoperative chest radiographs document the location of the catheter tip and demonstrate the redundant catheter in the right hemithorax (Fig 2). The posterior aspect of the fifth rib was then notched superiorly to allow the catheter to exit from the hemithorax without being compressed between the fourth and fifth ribs. A 10F chest tube was then placed through a separate incision and the thoracotomy was closed in a standard fashion. The shunt valve was then exposed on the posterior parietal area, the existing distal catheter was removed, and the new distal catheter was advanced through a subcutaneous tunnel from the thoracotomy incision and connected to the shunt valve outlet. Perioperatively and postoperatively the patient did well. He was discharged from the hospital on postoperative day 11 without further incident. Fourteen months have elapsed from the time of this shunt placement. The patient has continued to do well without recurrence of shunt infection or need for additional shunt revision or lengthening. Journalof Pediafric Surgery, Vol 27, No 5 (May), 1992: pp 642-644
VENTRICULOATRIAL
SHUNT USING AZYGOS VEIN
A
Fig 1.
Limited right thoracotomy
and exposure of the azygos vein.
DISCUSSION
The preferred site of distal catheter placement has been the peritoneum, which provides a sterile site with a high capacity for absorption of CSF. The multiple types of distal catheter complications in ventriculoperitoneal shunts are well documented.1,2 In this patient these complications included catheter infection, hernia formation, cyst formation, and abscess/ fistula formation. The multiple abdominal procedures, infections, and poor outcome of prior ventriculoperitoneal shunts precluded the final internalization of this patient’s shunt into the peritoneum or intraabdominal organs. The ventriculoatrial system of CSF shunting is well tolerated and effective, although not without potential significant associated complications. Pulmonary embolus, venous thrombosis, atria1 perforation, arrhythmias, and endocarditis have al1 been reported.3 Therefore, preference is given to ventriculoperitoneal shunting and the ventriculoatrial shunt remains one of second choice at this institution for the adult population. In the pediatric population, the ventriculoatrial shunt is often a more difficult type of shunt to place. Additionally there is another set of problems; those related to the somatic growth of the child. Growth and subsequent traction on the catheter can
643
act to displace the catheter superiorly, out of the right atrium and into the superior vena cava or more distal venous system. The incidence of shunt failure secondary to distal obstruction increases as the shunt tip comes to lie at increasing distances above the right atrium. The risks of complete venous occlusion and thrombosis likewise increase. Traction secondary to growth may also cause more proximal shunt failure with separation of the shunt catheter at the level of the shunt valve. In addition to causing shunt failure, this has the potential for causing the more serious complication of free catheter embolization into the heart. Consequently, we generally do not recommend the routine use of ventriculoatrial shunts in the pediatric population. We reserve the use of pediatric ventriculoatrial shunts for cases in which the standard ventriculoperitoneal shunt is not feasible. The two main problems with instituting ventriculoatrial shunting in this patient were the relative inaccessibility of the deep venous system and the need to accommodate future growth of the infant. Placement of the distal catheter into the right atrium via the azygos vein as described provided a solution to the problem of access and placement of redundant catheter into the right hemithorax provides additional catheter length to compensate for the future growth of the patient. Review of the literature documents an approach by Milhorat and McClenathan in which direct ventriculocardiac shunting was performed with redundant catheter left coiled in a Silastic pouch in the thoracic
Fig 2. Chest radiograph documenting the position of the distal catheter in the right atrium and showing the redundant catheter coiled in the right hemithorax.
644
REDO ET AL
cavity.4 However, this approach required violation of the pericardium and the myocardium itself. In summary, a technique is presented for ventriculoatrial shunt placement via the azygos vein for patients with limited venous access and in whom future lengthening procedures would be problematic.
In addition to allowing the long-term placement of ventriculoatrial shunts, the described procedure may also find use as a method of securing long-term vascular access in those pediatric patients requiring prolonged parenteral nutrition or other long-term parenteral therapy.
REFERENCES 1. Davidson RI: Peritoneal bypass in the treatment of hydrocephalus: Historical review and abdominal complications. J Neural Neurosurg Psychiatry 396406451976 2. Agha FP, Amendda MA, Shirazi KK, et al: Abdominal complications of venticulo-peritoneal shunts with emphasis on the role of imaging methods. Surg Gynecol Obstet 156:473-478,1983
3. McLaurin RL: Ventricular shunts: Complications and results, in McLaurin RL (ed): Pediatric Neurosurgery (ed 2). Philadelphia, PA, Saunders, 1989, pp 219-229 4. Milhorat TH, McClenathan JE: Direct cardiac shunt for hydrocephalus of infancy and childhood. J Neurosurg 42:605-608, 1975
Ventriculoatrial
Shunt Utilizing
By S. Frank Redo, Armann
Ciccarelli,
Jamshid
the Azygos Vein Ghajar, and Miles Dinner
New York, New York l Long-term ventricular cerebrospinal fluid shunting prove difficult in the neonatal population, particularly those neonates who have had previous abdominal vascular procedures. This article presents a technique providing vascular access for ventriculoatrial shunting the azygos vein for patients with limited vascular access in whom ventriculoperitoneal shunting is not feasible. Copyright o 7992 by W. 8. Saunders Company
can in and of via and
INDEX WORDS: Vascular access, azygos vein; hydrocephalus; ventriculoatrial shunt; ventriculoperitoneal shunt.
NTRICULOPERITONEAL shunts have been the preferred procedure for decompression in patients with hydrocephalus. However, there are some infants who, because of previous shunt revisions, infections, abdominal operations, and many central venous line placements for long-term parenteral nutritional support, have severely limited options for placement of the distal end of cerebrospinal fluid (CSF) shunt catheters. The following case report presents an alternate method of vascular access for CSF shunting in an infant with a complex surgical history and multiple prior abdominal and vascular operations.
v”
CASE REPORT A 14-month-old boy, the product of a 27-week gestation. had postnatal problems including bronchopulmonary dysplasia, patent ductus arteriosus, and bilateral hydrocephalus. Early operative procedures included ligation of the patent ductus and bilateral ventriculoperitoneal shunts. Complications of the ventriculoperitoneal shunts included shunt infections, hernia formation, abdominal cyst and abdominal abscess formation and enterocutaneous fistula. In conjunction to these complications the patient underwent multiple revisions of the CSF shunts. Long-term parenteral nutritional support was required by way of in-dwelling central venous lines. Multiple revisions of these lines were done due to infection, thrombosis, and dislodgement. After a long and difficult hospital course exceeding 12 months. the patient had improved to the point at which he was tolerating enteral feedings and was sepsis free. At this point he required only
From the Divisions of Pediatric Surgery and Neurosurgery, Department of Surgery, and the Department of Anesthesiology, New York Hospital-Cornell Medical Center, New York, NY Date accepted: November 1, 1991. Address reprint requests to S. Frank Redo, MD, Chief; Division of Pediatric Surgery, Room N-723, New York Hospital-Cornell Medical Center, 525 E 68th St, New York, NYlOO21. Copyright 0 1992 by W.B. Saunders Company 0022-3468/9212705-0027$03.0010 642
final internalization of his ventriculoperitoneal shunt, which had been externalized following prior formation of an intraabdominal abscess. Because of the multiple problems with ventriculoperitoneal shunts already encountered in this patient, it was elected to internalize this shunt into the central venous system. Magnetic resonance imaging and ultrasound Doppler studies were performed. These documented persistent inferior vena cava thrombosis and thrombosis and occlusion of the internal and external jugular venous systems bilaterally. Therefore, options for shunt placement into the central venous system were severely restricted as would be future shunt revisions. Given the need for long-term shunt placement, a growing child, and the need to avoid distal shunt revision, it was elected to attempt internalization of the shunt into the right atrium via the azygos vein with plans to leave redundant catheter in the right hemithorax to allow future growth of the infant without the need for future shunt lengthening procedures.
Operative Procedure A right lateral thoracotomy was done through the fourth intercostal space. Multiple adhesions in the right hemithorax (the result of prior closed tube thoracostomy) were taken down and the right lung was retracted medially. The posterior pleura was incised thereby exposing the superior aspect of the azygos vein (Fig 1). Proximal and distal control of the vein was obtained and superior venous tributaries were ligated. A 30-cm length of 0.25-cm diameter silastic catheter was filled with normal saline and connected to an electrocardiograph monitor via a sterile electrical lead. This provided continuous monitoring of the catheter position. A small venotomy was made in the arch of the azygos vein and with manual compression of the superior vena cava above the azygos-superior vena cava junction, the catheter was directed into the right atrium. Final positioning was confirmed by P wave inversion on the monitoring electrocardiogram indicating suprasinoatrial node placement. To accommodate the future growth of the infant and to avoid the need for catheter lengthening procedures, a 30-cm coil of redundant catheter was placed into the right hemithorax. Intraoperative chest radiographs document the location of the catheter tip and demonstrate the redundant catheter in the right hemithorax (Fig 2). The posterior aspect of the fifth rib was then notched superiorly to allow the catheter to exit from the hemithorax without being compressed between the fourth and fifth ribs. A 10F chest tube was then placed through a separate incision and the thoracotomy was closed in a standard fashion. The shunt valve was then exposed on the posterior parietal area, the existing distal catheter was removed, and the new distal catheter was advanced through a subcutaneous tunnel from the thoracotomy incision and connected to the shunt valve outlet. Perioperatively and postoperatively the patient did well. He was discharged from the hospital on postoperative day 11 without further incident. Fourteen months have elapsed from the time of this shunt placement. The patient has continued to do well without recurrence of shunt infection or need for additional shunt revision or lengthening. Journalof Pediafric Surgery, Vol 27, No 5 (May), 1992: pp 642-644
VENTRICULOATRIAL
SHUNT USING AZYGOS VEIN
A
Fig 1.
Limited right thoracotomy
and exposure of the azygos vein.
DISCUSSION
The preferred site of distal catheter placement has been the peritoneum, which provides a sterile site with a high capacity for absorption of CSF. The multiple types of distal catheter complications in ventriculoperitoneal shunts are well documented.1,2 In this patient these complications included catheter infection, hernia formation, cyst formation, and abscess/ fistula formation. The multiple abdominal procedures, infections, and poor outcome of prior ventriculoperitoneal shunts precluded the final internalization of this patient’s shunt into the peritoneum or intraabdominal organs. The ventriculoatrial system of CSF shunting is well tolerated and effective, although not without potential significant associated complications. Pulmonary embolus, venous thrombosis, atria1 perforation, arrhythmias, and endocarditis have al1 been reported.3 Therefore, preference is given to ventriculoperitoneal shunting and the ventriculoatrial shunt remains one of second choice at this institution for the adult population. In the pediatric population, the ventriculoatrial shunt is often a more difficult type of shunt to place. Additionally there is another set of problems; those related to the somatic growth of the child. Growth and subsequent traction on the catheter can
643
act to displace the catheter superiorly, out of the right atrium and into the superior vena cava or more distal venous system. The incidence of shunt failure secondary to distal obstruction increases as the shunt tip comes to lie at increasing distances above the right atrium. The risks of complete venous occlusion and thrombosis likewise increase. Traction secondary to growth may also cause more proximal shunt failure with separation of the shunt catheter at the level of the shunt valve. In addition to causing shunt failure, this has the potential for causing the more serious complication of free catheter embolization into the heart. Consequently, we generally do not recommend the routine use of ventriculoatrial shunts in the pediatric population. We reserve the use of pediatric ventriculoatrial shunts for cases in which the standard ventriculoperitoneal shunt is not feasible. The two main problems with instituting ventriculoatrial shunting in this patient were the relative inaccessibility of the deep venous system and the need to accommodate future growth of the infant. Placement of the distal catheter into the right atrium via the azygos vein as described provided a solution to the problem of access and placement of redundant catheter into the right hemithorax provides additional catheter length to compensate for the future growth of the patient. Review of the literature documents an approach by Milhorat and McClenathan in which direct ventriculocardiac shunting was performed with redundant catheter left coiled in a Silastic pouch in the thoracic
Fig 2. Chest radiograph documenting the position of the distal catheter in the right atrium and showing the redundant catheter coiled in the right hemithorax.
644
REDO ET AL
cavity.4 However, this approach required violation of the pericardium and the myocardium itself. In summary, a technique is presented for ventriculoatrial shunt placement via the azygos vein for patients with limited venous access and in whom future lengthening procedures would be problematic.
In addition to allowing the long-term placement of ventriculoatrial shunts, the described procedure may also find use as a method of securing long-term vascular access in those pediatric patients requiring prolonged parenteral nutrition or other long-term parenteral therapy.
REFERENCES 1. Davidson RI: Peritoneal bypass in the treatment of hydrocephalus: Historical review and abdominal complications. J Neural Neurosurg Psychiatry 396406451976 2. Agha FP, Amendda MA, Shirazi KK, et al: Abdominal complications of venticulo-peritoneal shunts with emphasis on the role of imaging methods. Surg Gynecol Obstet 156:473-478,1983
3. McLaurin RL: Ventricular shunts: Complications and results, in McLaurin RL (ed): Pediatric Neurosurgery (ed 2). Philadelphia, PA, Saunders, 1989, pp 219-229 4. Milhorat TH, McClenathan JE: Direct cardiac shunt for hydrocephalus of infancy and childhood. J Neurosurg 42:605-608, 1975
