2. Neurosurgery 31; 1136-1137, 1992
Christian Raftopoulos Arlette Vandesteene Brussels, Belgium REFERENCES: (1-4) 1.
Brandt RL, Foley WJ, Fink GH, Regan WJ:
3.
4.
Spinal Cord Astrocytomas: Results of Therapy To the Editor: In their article on spinal cord astrocytomas (1), Sandler and colleagues concluded that they were unable, in this small series, to demonstrate a relationship between the magnitude of resection and outcome. The two outcomes the authors chose to consider were survival and time to recurrence. To acquire a sufficient number of patients, the authors reached back to 1975, a time when intraoperative ultrasonography was not routinely used in the management of these lesions. The choice of outcomes is, I think, inappropriate in the consideration of these relatively benign lesions. Of greater concern is functional outcome, which is not addressed. I was one of a number of pediatric neurosurgeons who went to New York University to observe Dr. Epstein's technique for the radical resection of these tumors. I was greatly encouraged by the ability, using intraoperative ultrasound, to delineate the boundaries of these intramedullary lesions (although a complete resection is probably achieved only infrequently). Based on that experience, I, too, began treating these children aggressively. I was pleased by the relief of pain, the improvement in function, and the ability to delay the initiation of radiation therapy and to follow the children with magnetic resonance imaging. Such a delay is particularly important when one considers the long-term effect of radiation on the growing spine. This, of course, was not achieved in every child, but it is these functional outcomes that should be considered. We must move away from the all too easily measured and reported outcomes of survival and recurrence and try to define outcomes that are more meaningful in terms of patient satisfaction. This is particularly true in such conditions as benign astrocytoma, where the numbers needed to demonstrate a significant effect are far beyond the experience of any neurosurgeon. Joan Venes Annapolis, Maryland
Downloaded from https://academic.oup.com/neurosurgery/article-abstract/31/6/1136/2752159 by East Carolina University user on 19 August 2019
Ventriculoatrial Shunt Distal Catheter Placement Using Transesophageal Echocardiography: Technical Note To the Editor: We read with interest the article by McGrail et al., (2) who report that transesophageal echocardiography can accurately localize the distal end of a ventriculoatrial shunt to the cavoatrial junction; whereas other methods like chest x-ray and intravenous recording can be inaccurate. For them, catheter placement under electrocardiogram control is sometimes "difficult," and intraoperative x-ray is useless if the catheter radiopacity is not strong enough to allow its detection. We think that even if transesophageal echocardiography appears to be an accurate method to distally place the shunt, this procedure has two practical limitations: 1) it required a neuroanesthesiologist well trained to perform this technique; and 2) the material is expensive and may be difficult to obtain for this particular purpose. In our experience with adults, when catheterizing the right facial vein, no more than 23 cm of tubing is required to reach the junction of the superior vena cava and right atrium. If such a length of tubing is associated with the largest-amplitude, downwarddeflecting P wave (just before the biphasic state), the catheter placement can be considered as correct (3). If it is difficult to thread the catheter into the superior vena cava or, exceptionally, if it is impossible to analyze the intravascular electrocardiogram, we take a spring wire guide from a central venous catheterization set and introduce it into the distal shunt catheter. This is done to avoid introducing the wire guide into the heart and to avoid damaging structures (1). This very simple procedure helps to guide the catheter into the superior vena cava and to strongly increase the catheter's radiopacity so that its detection by chest x-ray is no longer a problem. As cardiac chambers do not have a constant projection on bony structures, the exact location of the catheter tip must be checked by intravenous electrocardiogram. If electrocardiographic patterns obtained during intravascular recordings are not convincing, which rarely happens, external two-dimensional echocardiography can be easily performed before the closure of the operative field (4). All this seems to us easier to perform than transesophageal echocardiography and is equally precise.
Mechanism of perforation of the heart with production of hydropericardium by a venous catheter and its prevention. A J Surg 119:311316, 1970. McGrail KM, Muzzi DA, Losasso TJ, Meyer FB: Ventriculoatrial shunt distal catheter placement using transesophageal echocardiography: Technical note. Neurosurgery 30:747-749, 1992. Shapiro HM, Drummond JC: Neurosurgical anesthesia and intracranial hypertension, in Miller RD (ed): Anesthesia. New York, Churchill Livingstone Inc., 1990, ed 3, vol 2, pp 1737-1784. Soyeur D, Born J, Lenelle J, Stevenaert A: Two- dimensional echocardiographic localization of intracardiac cerebrospinal fluid shunt catheters. Neurosurgery 14:2-7, 1984.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
Neurosurgery 1992-98 December 1992, Volume 31, Number 6 1136 Correspondence Departments: Correspondence
Christian Raftopoulos Arlette Vandesteene Brussels, Belgium REFERENCES: (1-4) 1.
Brandt RL, Foley WJ, Fink GH, Regan WJ:
3.
4.
Spinal Cord Astrocytomas: Results of Therapy To the Editor: In their article on spinal cord astrocytomas (1), Sandler and colleagues concluded that they were unable, in this small series, to demonstrate a relationship between the magnitude of resection and outcome. The two outcomes the authors chose to consider were survival and time to recurrence. To acquire a sufficient number of patients, the authors reached back to 1975, a time when intraoperative ultrasonography was not routinely used in the management of these lesions. The choice of outcomes is, I think, inappropriate in the consideration of these relatively benign lesions. Of greater concern is functional outcome, which is not addressed. I was one of a number of pediatric neurosurgeons who went to New York University to observe Dr. Epstein's technique for the radical resection of these tumors. I was greatly encouraged by the ability, using intraoperative ultrasound, to delineate the boundaries of these intramedullary lesions (although a complete resection is probably achieved only infrequently). Based on that experience, I, too, began treating these children aggressively. I was pleased by the relief of pain, the improvement in function, and the ability to delay the initiation of radiation therapy and to follow the children with magnetic resonance imaging. Such a delay is particularly important when one considers the long-term effect of radiation on the growing spine. This, of course, was not achieved in every child, but it is these functional outcomes that should be considered. We must move away from the all too easily measured and reported outcomes of survival and recurrence and try to define outcomes that are more meaningful in terms of patient satisfaction. This is particularly true in such conditions as benign astrocytoma, where the numbers needed to demonstrate a significant effect are far beyond the experience of any neurosurgeon. Joan Venes Annapolis, Maryland
Downloaded from https://academic.oup.com/neurosurgery/article-abstract/31/6/1136/2752159 by East Carolina University user on 19 August 2019
Ventriculoatrial Shunt Distal Catheter Placement Using Transesophageal Echocardiography: Technical Note To the Editor: We read with interest the article by McGrail et al., (2) who report that transesophageal echocardiography can accurately localize the distal end of a ventriculoatrial shunt to the cavoatrial junction; whereas other methods like chest x-ray and intravenous recording can be inaccurate. For them, catheter placement under electrocardiogram control is sometimes "difficult," and intraoperative x-ray is useless if the catheter radiopacity is not strong enough to allow its detection. We think that even if transesophageal echocardiography appears to be an accurate method to distally place the shunt, this procedure has two practical limitations: 1) it required a neuroanesthesiologist well trained to perform this technique; and 2) the material is expensive and may be difficult to obtain for this particular purpose. In our experience with adults, when catheterizing the right facial vein, no more than 23 cm of tubing is required to reach the junction of the superior vena cava and right atrium. If such a length of tubing is associated with the largest-amplitude, downwarddeflecting P wave (just before the biphasic state), the catheter placement can be considered as correct (3). If it is difficult to thread the catheter into the superior vena cava or, exceptionally, if it is impossible to analyze the intravascular electrocardiogram, we take a spring wire guide from a central venous catheterization set and introduce it into the distal shunt catheter. This is done to avoid introducing the wire guide into the heart and to avoid damaging structures (1). This very simple procedure helps to guide the catheter into the superior vena cava and to strongly increase the catheter's radiopacity so that its detection by chest x-ray is no longer a problem. As cardiac chambers do not have a constant projection on bony structures, the exact location of the catheter tip must be checked by intravenous electrocardiogram. If electrocardiographic patterns obtained during intravascular recordings are not convincing, which rarely happens, external two-dimensional echocardiography can be easily performed before the closure of the operative field (4). All this seems to us easier to perform than transesophageal echocardiography and is equally precise.
Mechanism of perforation of the heart with production of hydropericardium by a venous catheter and its prevention. A J Surg 119:311316, 1970. McGrail KM, Muzzi DA, Losasso TJ, Meyer FB: Ventriculoatrial shunt distal catheter placement using transesophageal echocardiography: Technical note. Neurosurgery 30:747-749, 1992. Shapiro HM, Drummond JC: Neurosurgical anesthesia and intracranial hypertension, in Miller RD (ed): Anesthesia. New York, Churchill Livingstone Inc., 1990, ed 3, vol 2, pp 1737-1784. Soyeur D, Born J, Lenelle J, Stevenaert A: Two- dimensional echocardiographic localization of intracardiac cerebrospinal fluid shunt catheters. Neurosurgery 14:2-7, 1984.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
Neurosurgery 1992-98 December 1992, Volume 31, Number 6 1136 Correspondence Departments: Correspondence
