A simple test of shunt function. the shuntgram Technical note
RICHARD C. DEWEY, M.D., EDWARDJ. KOSNIK, M.D., AND MARTIN P. SAYERS, M.D.
Division of Neurological Surgery, The Ohio State University and Columbus Children's Hospital, Columbus, Ohio ~" The authors present an x-ray film method to ascertain the function of ventricular shunts in hydrocephalic patients. No special equipment is required. Representative x-ray films and analysis of results in 131 determinations are presented. KEY WORDS
~
shunt
9 ventricle
ANY methods of ascertaining shunt function in treated hydrocephalic patients have been presented? ,o The complexity of these determinations has limited their clinical applicability, especially in pediatric services with a parade of irritable, vomiting children. In the past 4 years at the Children's Hospital, Columbus, Ohio, we have used a simple test, the shuntgram, as a reliable adjunct in the diagnosis of shunt function.
M
Clinical Material and Methods All patients undergoing evaluation of shunt function between J a n u a r y , 1971, and December, 1973, for whom complete records were available were included in this study, for a total of 131 determinations in 91 patients. Approximately one-half of the data was obtained as a prospective study. The mean
J. Neurosurg. / Volume 44 / January, 1976
9 hydrocephalus
follow-up was 18 months. Table 1 summarizes the patient population. TABLE 1
Summary of hydrocephalic patient population Etiology* raphic defects : meningomyelocele encephalocele congenital acquired : trauma, SAH infection tumor other communicating noncommunicating
No. of Cases 45 42 3 28 18 6 5 5 2 50 ~o 50 7o
* SAH = subarachnoid hemorrhage. 121
R. C. D e w e y , E. J. K o s n i k a n d M. P. S a y e r s The technique involves meticulous surgical and injected, if no mechanical disruptions, preparation of the skin overlying the valve sleeves or kinks are seen and if the shunt empand percutaneous cannulization with a 25- ties in 3 minutes (Fig. 1). In this series of 131 gauge needle. Aspiration is attempted determinations, 49 were considered normal; followed by injection of 2 cc of Conray-60 of this group only 10 patients were reshunted dye. The first x-ray film is taken during injec- over the following 17 months, with two tion of dye. Exposure time is 1/60 sec or less; reshunted within the first week. Both patients slower times fail to "freeze" the distal with shunt revisions in the first week were catheter, which moves with each heartbeat. assessed early in the series before the reAdditional films are obtained at 3-minute in- quirements for short x-ray exposure and intervals until clearing occurs. If no clearing oc- jection during the first filming were fully apcurs after the 9-minute film, the shunt is preciated. If one considers these two patients pumped and a final film is taken. Depending as failures, the diagnostic accuracy was 96%. on the ease of aspiration and injection, the The mean intracranial pressure when clearing time, and the presence or absence of measured in this group was 80 mm CSF. leaks, kinks or mesothelial sleeves, the shunt is placed in normal, abnormal or question- The Abnormal Shunt able categories. Table 2 summarizes the The shunt was considered abnormal if results and follow-up times for each of these aspiration or injection was difficult and it categories. Times listed are related to the date failed to clear in 9 minutes, if an obvious disof implantation of the shunt being tested. connection (Fig. 2), block or sleeve was demonstrated, or if the shunt failed to clear Results after pumping (Fig. 3). Of 63 determinations in the abnormal group, 46 shunts were revised The Normal Shunt in the first week and half of these in the first We have considered the shunt normal if 48 hours. The mean intracranial pressure of cerebrospinal fluid (CSF) is easily aspirated those measured was 295 mm CSF.
Ft~. 1. The normal shuntgram. Left: One to 2 cc of CSF were aspirated from the Holter reservoir, and 2 cc of Conray dye were injected while this picture was made. There are no structural abnormalities. Right: Three minutes later there is complete clearing (arrow). 122
J. Neurosurg. / Volume 44 / January, 1976
Shunt function test: the shuntgram The Questionable Shunt All shuntgrams not fitting into the two categories found above were placed in the questionable group. This group included shunts where CSF was easily aspirated and injected and which showed no mechanical reason for block, yet required 6 minutes or longer for the contrast material to clear; and shunts which cleared in 3 minutes, yet showed kinking, mesothelial sleeve, dislocation, or difficulty in aspirating or injecting (Fig. 4). Of 19 shunts placed in this category, 10 patients required revisions over the next 14 months, seven within the first week. Five patients had simultaneous measurement of the ventricular pressure which averaged 102 mm CSF.
Comment
FIG. 2. Abnormal shuntgram. Injected Conray dye extravasates through a shunt disconnection in the neck (arrow).
Our experience is mostly with the Holter ventriculojugular shunt system, and data may only be applicable to venous or cardiac shunts. Figure 5 shows a similar determination for a functioning Pudenz ventriculojugular shunt, and Fig. 6 shows a Holter ventriculoperitoneal shunt functioning normally.
F~. 3. Abnormal shuntgram. Left: The tip of the venous catheter is at the T-3 level (large arrow). There is reflux of Conray dye through a mesothelial sleeve (small arrows). Right." Twelve minutes later, after pumping reservoir, there is no clearing (arrow).
J. Neurosurg. / Volume 44 / January, 1976
123
R. C. Dewey, E. J. Kosnik and M. P. Sayers
FIG. 4. Questionable shuntgram. Left.' Injection of Conray dye shows shunt disconnection in the neck (large arrow). The distal venous catheter looks normal (small arrows). Right: The 3-minute film shows complete clearing of the Holter reservoir (large arrow) and distal catheter (small arrows).
Fro. 5. Normal shuntgram of a Pudenz ventriculojugular shunt, with complete clearing in 3 minutes (arrow). 124
J. Neurosurg. / Volume 44 / January, 1976
Shunt function test: the shuntgram
F~6. 6. N o r m a l s h u n t g r a m of a Holter ventriculoperitoneal shunt. Three minute film (right) shows complete clearing of reservoir (large arrow) and distal catheter (small arrows).
TABLE
2
Summary ()/ the reslt/ls attd ~llow-ttp times ./or shuat procedure Abnormal
FIG. 7. S u b d u r a l or s u b a r a c h n o i d injection of Conray dye. N o t e needle passing through the reservoir. There were no sequelae of this inadvertant injection.
J. Neurosurg. / Volume 44 /January, 1976
Questionable
Normal
no. tested 63 19 49 shunt age 27 36 19 (mos) age range 1 day 91 mos l 115 mos 1 day 9 9 m o s no. reshunted* 46 l0 10 reshunted 68 36 4 1 wk~ median time 2 days 6 days 3 mos of revision? number 20 9 38 unrevised* unrevised* 32 47 78 mean follow17 14 17 up (mos) follow-up 1-33 1-26 1-33 range (mos) ventricular 295 102 80 pressure (mm CSF) number 25 5 8 measured pressure 20-600 30-160 0-270 range * These results are for the entire follow-up period. t These measurements are taken from the date of shuntgram. 125
R. C. Dewey, E. J. Kosnik and M. P. Sayers There have been no complications associated with multiple perforations of the Holter valve. No patient has subsequently developed a shunt infection. On one occasion the needle was inadvertently passed through the reservoir into the subarachnoid space of a young child (Fig. 7), but there were no sequelae. An air block causes slow emptying and the test must be repeated, usually after a 24-hour delay if an air bubble becomes trapped in the valve or catheter. There are no significant complications of percutaneous cannulization of the shunt reservoir, and in our hands the diagnostic predictability of a " n o r m a l " shuntgram is 96%. References
1. Andersson H, L~fgren J: Hydrodynamic evaluation of shunt performance in hydrocephalus. Dev Med Child Neurol Suppl 16:30-34, 1968 2. Atkinson JR, Shurtleff DB, Foltz EL: Radio telemetry for the measurement of intracranial pressure. J Ncurosurg 27:428-432, 1967 3. Davidoff LM, Chamlin M: The "fontanometer": adaptation of the Schiotz tonometer for the determination of intracranial pressure in the neonatal and early periods of infancy. Pediatrics 24:1065-1068, 1959
126
4. Forrest DM, Tsingoglou S: The false fontanelle as a practical method of long-term testing of intracranial pressure. Dev Med Child Neurol Suppl 16:17+, 1968 5. Go KG, Lakke JP, Beks JW: A harmless method for the assessment of the patency of ventriculoatrial shunts in hydrocephalus. Dev Med Child Neurol Suppl 16:100+, 1968 6. Hoppenstein R: A device for measuring intracranial pressure: Lancet 1:90-91, 1965 7. Jeppsson S: Echoencephalography V. A method for recording the intracranial pressure with the aid of echoencephalographic technique. A preliminary report. Acta Chir Scand 128:218-224, 1964 8. Matin P, Goodwin DA, DeNardo GL: Cerebrospinal fluid scanning and ventricular shunts. Radiology 94:435-438, 1970 9. Rowan JO, Robertson JS: Evaluation of surgical ventricular shunts using sodium pertechnetate (Na99TcmO4). Br J Radiol 43:831, 1970 10. Shulman K, Marmarou A: Analysis of intracranial pressure in hydrocephalus. Dev Med Child Neurol Suppl 16:11-16, 1968
Address reprint requests to: Richard C. Dewey, M.D., Box 1067, Missoula, Montana 59801.
J. Neurosurg. / Volume 44 /January, 1976
RICHARD C. DEWEY, M.D., EDWARDJ. KOSNIK, M.D., AND MARTIN P. SAYERS, M.D.
Division of Neurological Surgery, The Ohio State University and Columbus Children's Hospital, Columbus, Ohio ~" The authors present an x-ray film method to ascertain the function of ventricular shunts in hydrocephalic patients. No special equipment is required. Representative x-ray films and analysis of results in 131 determinations are presented. KEY WORDS
~
shunt
9 ventricle
ANY methods of ascertaining shunt function in treated hydrocephalic patients have been presented? ,o The complexity of these determinations has limited their clinical applicability, especially in pediatric services with a parade of irritable, vomiting children. In the past 4 years at the Children's Hospital, Columbus, Ohio, we have used a simple test, the shuntgram, as a reliable adjunct in the diagnosis of shunt function.
M
Clinical Material and Methods All patients undergoing evaluation of shunt function between J a n u a r y , 1971, and December, 1973, for whom complete records were available were included in this study, for a total of 131 determinations in 91 patients. Approximately one-half of the data was obtained as a prospective study. The mean
J. Neurosurg. / Volume 44 / January, 1976
9 hydrocephalus
follow-up was 18 months. Table 1 summarizes the patient population. TABLE 1
Summary of hydrocephalic patient population Etiology* raphic defects : meningomyelocele encephalocele congenital acquired : trauma, SAH infection tumor other communicating noncommunicating
No. of Cases 45 42 3 28 18 6 5 5 2 50 ~o 50 7o
* SAH = subarachnoid hemorrhage. 121
R. C. D e w e y , E. J. K o s n i k a n d M. P. S a y e r s The technique involves meticulous surgical and injected, if no mechanical disruptions, preparation of the skin overlying the valve sleeves or kinks are seen and if the shunt empand percutaneous cannulization with a 25- ties in 3 minutes (Fig. 1). In this series of 131 gauge needle. Aspiration is attempted determinations, 49 were considered normal; followed by injection of 2 cc of Conray-60 of this group only 10 patients were reshunted dye. The first x-ray film is taken during injec- over the following 17 months, with two tion of dye. Exposure time is 1/60 sec or less; reshunted within the first week. Both patients slower times fail to "freeze" the distal with shunt revisions in the first week were catheter, which moves with each heartbeat. assessed early in the series before the reAdditional films are obtained at 3-minute in- quirements for short x-ray exposure and intervals until clearing occurs. If no clearing oc- jection during the first filming were fully apcurs after the 9-minute film, the shunt is preciated. If one considers these two patients pumped and a final film is taken. Depending as failures, the diagnostic accuracy was 96%. on the ease of aspiration and injection, the The mean intracranial pressure when clearing time, and the presence or absence of measured in this group was 80 mm CSF. leaks, kinks or mesothelial sleeves, the shunt is placed in normal, abnormal or question- The Abnormal Shunt able categories. Table 2 summarizes the The shunt was considered abnormal if results and follow-up times for each of these aspiration or injection was difficult and it categories. Times listed are related to the date failed to clear in 9 minutes, if an obvious disof implantation of the shunt being tested. connection (Fig. 2), block or sleeve was demonstrated, or if the shunt failed to clear Results after pumping (Fig. 3). Of 63 determinations in the abnormal group, 46 shunts were revised The Normal Shunt in the first week and half of these in the first We have considered the shunt normal if 48 hours. The mean intracranial pressure of cerebrospinal fluid (CSF) is easily aspirated those measured was 295 mm CSF.
Ft~. 1. The normal shuntgram. Left: One to 2 cc of CSF were aspirated from the Holter reservoir, and 2 cc of Conray dye were injected while this picture was made. There are no structural abnormalities. Right: Three minutes later there is complete clearing (arrow). 122
J. Neurosurg. / Volume 44 / January, 1976
Shunt function test: the shuntgram The Questionable Shunt All shuntgrams not fitting into the two categories found above were placed in the questionable group. This group included shunts where CSF was easily aspirated and injected and which showed no mechanical reason for block, yet required 6 minutes or longer for the contrast material to clear; and shunts which cleared in 3 minutes, yet showed kinking, mesothelial sleeve, dislocation, or difficulty in aspirating or injecting (Fig. 4). Of 19 shunts placed in this category, 10 patients required revisions over the next 14 months, seven within the first week. Five patients had simultaneous measurement of the ventricular pressure which averaged 102 mm CSF.
Comment
FIG. 2. Abnormal shuntgram. Injected Conray dye extravasates through a shunt disconnection in the neck (arrow).
Our experience is mostly with the Holter ventriculojugular shunt system, and data may only be applicable to venous or cardiac shunts. Figure 5 shows a similar determination for a functioning Pudenz ventriculojugular shunt, and Fig. 6 shows a Holter ventriculoperitoneal shunt functioning normally.
F~. 3. Abnormal shuntgram. Left: The tip of the venous catheter is at the T-3 level (large arrow). There is reflux of Conray dye through a mesothelial sleeve (small arrows). Right." Twelve minutes later, after pumping reservoir, there is no clearing (arrow).
J. Neurosurg. / Volume 44 / January, 1976
123
R. C. Dewey, E. J. Kosnik and M. P. Sayers
FIG. 4. Questionable shuntgram. Left.' Injection of Conray dye shows shunt disconnection in the neck (large arrow). The distal venous catheter looks normal (small arrows). Right: The 3-minute film shows complete clearing of the Holter reservoir (large arrow) and distal catheter (small arrows).
Fro. 5. Normal shuntgram of a Pudenz ventriculojugular shunt, with complete clearing in 3 minutes (arrow). 124
J. Neurosurg. / Volume 44 / January, 1976
Shunt function test: the shuntgram
F~6. 6. N o r m a l s h u n t g r a m of a Holter ventriculoperitoneal shunt. Three minute film (right) shows complete clearing of reservoir (large arrow) and distal catheter (small arrows).
TABLE
2
Summary ()/ the reslt/ls attd ~llow-ttp times ./or shuat procedure Abnormal
FIG. 7. S u b d u r a l or s u b a r a c h n o i d injection of Conray dye. N o t e needle passing through the reservoir. There were no sequelae of this inadvertant injection.
J. Neurosurg. / Volume 44 /January, 1976
Questionable
Normal
no. tested 63 19 49 shunt age 27 36 19 (mos) age range 1 day 91 mos l 115 mos 1 day 9 9 m o s no. reshunted* 46 l0 10 reshunted 68 36 4 1 wk~ median time 2 days 6 days 3 mos of revision? number 20 9 38 unrevised* unrevised* 32 47 78 mean follow17 14 17 up (mos) follow-up 1-33 1-26 1-33 range (mos) ventricular 295 102 80 pressure (mm CSF) number 25 5 8 measured pressure 20-600 30-160 0-270 range * These results are for the entire follow-up period. t These measurements are taken from the date of shuntgram. 125
R. C. Dewey, E. J. Kosnik and M. P. Sayers There have been no complications associated with multiple perforations of the Holter valve. No patient has subsequently developed a shunt infection. On one occasion the needle was inadvertently passed through the reservoir into the subarachnoid space of a young child (Fig. 7), but there were no sequelae. An air block causes slow emptying and the test must be repeated, usually after a 24-hour delay if an air bubble becomes trapped in the valve or catheter. There are no significant complications of percutaneous cannulization of the shunt reservoir, and in our hands the diagnostic predictability of a " n o r m a l " shuntgram is 96%. References
1. Andersson H, L~fgren J: Hydrodynamic evaluation of shunt performance in hydrocephalus. Dev Med Child Neurol Suppl 16:30-34, 1968 2. Atkinson JR, Shurtleff DB, Foltz EL: Radio telemetry for the measurement of intracranial pressure. J Ncurosurg 27:428-432, 1967 3. Davidoff LM, Chamlin M: The "fontanometer": adaptation of the Schiotz tonometer for the determination of intracranial pressure in the neonatal and early periods of infancy. Pediatrics 24:1065-1068, 1959
126
4. Forrest DM, Tsingoglou S: The false fontanelle as a practical method of long-term testing of intracranial pressure. Dev Med Child Neurol Suppl 16:17+, 1968 5. Go KG, Lakke JP, Beks JW: A harmless method for the assessment of the patency of ventriculoatrial shunts in hydrocephalus. Dev Med Child Neurol Suppl 16:100+, 1968 6. Hoppenstein R: A device for measuring intracranial pressure: Lancet 1:90-91, 1965 7. Jeppsson S: Echoencephalography V. A method for recording the intracranial pressure with the aid of echoencephalographic technique. A preliminary report. Acta Chir Scand 128:218-224, 1964 8. Matin P, Goodwin DA, DeNardo GL: Cerebrospinal fluid scanning and ventricular shunts. Radiology 94:435-438, 1970 9. Rowan JO, Robertson JS: Evaluation of surgical ventricular shunts using sodium pertechnetate (Na99TcmO4). Br J Radiol 43:831, 1970 10. Shulman K, Marmarou A: Analysis of intracranial pressure in hydrocephalus. Dev Med Child Neurol Suppl 16:11-16, 1968
Address reprint requests to: Richard C. Dewey, M.D., Box 1067, Missoula, Montana 59801.
J. Neurosurg. / Volume 44 /January, 1976
