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Sacral Neuromodulation in Children With Dysfunctional Elimination Syndrome: Description of Incisionless First Stage and Second Stage Without Fluoroscopy
Surgical Techniques in Urology Sacral Neuromodulation in Children With Dysfunctional Elimination Syndrome: Description of Incisionless First Stage and Second Stage Without Fluoroscopy Shawn M. McGee, Jonathan C. Routh, Candace F. Granberg, Timothy J. Roth, Pam Hollatz, David R. Vandersteen, and Yuri Reinberg OBJECTIVES
METHODS
RESULTS
CONCLUSIONS
To detail a percutaneous technique of sacral nerve neuromodulation (SN) that eliminates the first-stage incisions and the need for second-stage fluoroscopy. Our group has previously described the results of SN in children with medically refractory dysfunctional elimination syndrome. The drawbacks to SN include the use of fluoroscopy and the need to reopen recent skin incisions during the second stage. This results in increased radiation exposure, poor cosmesis, and possible wound infection. The incisionless first stage consisted of percutaneously tunneling the temporary external appliance to the contralateral axillary line at the buttock after localization of the S3 nerve root and placement of a quadripolar tined lead under fluoroscopic guidance. A subcutaneous bolus of methylene blue marked the lead connector site, obviating the need for later fluoroscopic localization to place the implantable pulse generator at the second stage. A total of 27 children with refractory dysfunctional elimination syndrome underwent SN using the InterStim device. Of the 27 patients, 19 underwent our modified technique. The operative time for our modified tunneling and placement technique was ⱕ2 minutes. The mean hospital stay was 0.6 day, with no patient requiring postoperative intravenous narcotics. At a mean follow-up of 35.9 months, no wound infections had occurred in the incisionless cohort compared with 1 postoperative wound infection requiring device explantation in the conventional lead placement group. The incisionless technique of SN device implantation is technically simple, quick to perform, and results in decreased radiation exposure, excellent pain control, and improved cosmesis without compromising the outcomes. UROLOGY 73: 641– 644, 2009. © 2009 Elsevier Inc.
S
acral nerve neuromodulation (SN) with the InterStim device (Medtronic, Minneapolis, MN) has been successfully applied to children with medically refractory dysfunction elimination syndrome (DES).1,2 DES is a constellation of chronic urinary symptoms that can be especially frustrating to the child, parents, and medical caregivers owing to the frequent evaluations and numerous medical therapies. Despite the initial success seen with the InterStim in the pediatric population, SN is currently reserved for children with DES who do not respond to conventional therapy such as medications and behavior modification. SN is an established Food and Drug Administrationapproved treatment for chronic urge incontinence, uriFrom the Department of Urology, Mayo Medical School and Mayo Clinic, Rochester, Minnesota; and Division of Urology, Children’s Hospital of Minnesota, Minneapolis, Minnesota Reprint requests: Shawn M. McGee, M.D., Department of Urology, Mayo Clinic, 200 First Street Southwest, Rochester MN 55905. E-mail: [email protected] Submitted: September 10, 2008, accepted (with revisions): October 27, 2008
© 2009 Elsevier Inc. All Rights Reserved
nary urgency, frequency, and nonobstructive urinary retention in adults.3 Previously, 12%-25% of women with dysfunctional elimination symptoms had admitted to DES-type symptoms as children.4 These chronic underlying lower urinary tract symptoms beginning in childhood have some investigators surmising that more aggressive diagnosis and treatment of DES in children might avert progressive dysfunctional elimination symptoms into adolescence. As such, small cohorts of children with debilitating and refractory DES have undergone SN in an attempt to alleviate their current symptoms and possibly future lower urinary tract dysfunction. As with all therapies and surgical procedures applied to patients, attempts have been made to use minimally invasive techniques to improve cosmesis and decrease pain and subsequent hospitalization time. This is especially true in the pediatric population. In addition, pediatric caregivers have strived to lessen children’s exposure to radiation to avert the increased risk of delayed development and possible malignancy. We report a modifica0090-4295/09/$34.00 doi:10.1016/j.urology.2008.10.067
641
tion to the 2-stage InterStim device implantation that eliminates the large surgical incisions and fluoroscopic exposure in children.
MATERIAL AND METHODS Patients With institutional review board approval, we evaluated 27 patients, including 18 girls and 9 boys with a mean age of 10.1 years (range 6-17) after SN with the InterStim (Medtronic) implantable device from December 2002 to March 2007. The children in the study had had no neurologic abnormalities and had previously been diagnosed with DES. The children were considered for SN only if they had remained symptomatic after 6 months of maximal medical management, including behavioral modification, timed voiding and defecation, biofeedback, and multiple pharmacologic therapies. The decision to proceed with SN was made by the individual patient and caregiver on a case by case basis.
Conventional 2-Stage Implanted Pulse Generator Placement The 2 stages of the procedure were performed at a single institution by 1 of 2 surgeons (Y.E.R. or D.R.V.). Prophylactic intravenous antibiotics were given to all patients before both stages. During the conventional first stage of SN implantation, percutaneous transforaminal access to the third sacral spinal nerve (S3) was achieved, and, once an appropriate neurologic response was elicited, a quadripolar tined lead was implanted. Before developing the incisionless first-stage technique, the extender leads of the temporary external neurostimulator device were subcutaneously tunneled laterally from the sacrum to one side of the patient and then to the contralateral side, after creating an incision, as previously described by Janknegt et al.5 The external neurostimulator device was then left in the patient for 2-6 weeks as a trial period. The second stage of the SN implantation was performed on patients who demonstrated a ⱖ50% improvement in voiding dysfunction during the trial period. During the conventional second stage, fluoroscopy was again used to locate the subcutaneous extender leads and connector before making an incision in the same location at which the previous gluteal incision was made in the first stage of the SN implantation. The implanted pulse generator (IPG) was then placed into a pocket created under the previous gluteal incision. All incisions were then closed with subcutaneous suturing.
Modified 2-Stage IPG Placement: Incisionless First Stage The incisionless first stage of SN implantation was performed at a single institution by the same surgeons who performed conventional IPG placement. Prophylactic intravenous antibiotics were given to all patients before both stages. During the incisionless first stage, percutaneous transforaminal access to the third sacral spinal nerve (S3) was achieved with fluoroscopy, as done with the conventional first stage. Once the appropriate neurologic response was elicited, a quadripolar tined lead was implanted. Unlike in the conventional technique, the extender leads of the temporary external neurostimulator device were subcutaneously tunneled laterally to the axillary line of the patient with a commercially available 14F ureteral access sheath applied 642
Figure 1. Temporary external lead exits child laterally at axillary line of patient after dilation of tract with commercially available 14F ureteral access sheath. Methylene tattoo marks connection to external lead (square along lead).
through the percutaneous site at which the quadripolar tined lead exited the skin (Fig. 1 and Video). The ureteral access sheath exited the patient’s skin laterally at the level of the gluteal cleft through a small stab wound (Fig. 1 and Video). The quadripolar tined lead and temporary external lead were then advanced through the ureteral access sheath laterally to the axillary line of the patient. After placing the quadripolar tined lead and temporary external lead through the subcutaneous tract, the eventual site of the permanent IPG was marked with methylene blue as a temporary tattoo at the site of the connector between the quadripolar tined lead and the temporary external lead on the patient’s gluteal region (Fig. 2 and Video). This step obviated the surgeon’s need to use fluoroscopy during the second stage when the permanent IPG was placed. The percutaneous site and lateral stab wound were closed with dermal bonding adhesive.
Modified 2-Stage IPG Placement: Second-Stage Without Fluoroscopy During the second stage of the IPG placement, fluoroscopy was not used throughout the procedure, secondary to the previously created methylene blue tattoo at the location of the eventual incision for IPG placement. At this point, the patient underwent a novel 4-5-cm incision over the location of the methylene blue tattoo to place the permanent IPG (Fig. 2). The incision was then closed with subcutaneous suturing.
Statistical Analysis The clinical features of interest were compared between the children undergoing our modified 2-stage procedure and those who underwent the conventional 2-stage procedure using the 2 or Fischer’s exact test, as appropriate. All tests were 2-sided, with P ⬍ .05 considered statistically significant. UROLOGY 73 (3), 2009
Figure 2. Final location of implanted pulse generator using our modified technique. Table 1. Clinical features
COMMENT
Variable
Total
Patients (n) Sex Female Male Age (y) Average Range Average interval between stages (d) Infection after placement (n)
27
9
18
19 8
7 2
12 6
Conventional
Incisionless
10.1 6-17 25.5
7 7-14 25.9
10 6-17 25.4
1 (3.7)
1 (11)
0
Data in parentheses are percentages.
RESULTS The average follow-up was 35.9 months (range 5-57) for all children undergoing IPG placement. Children undergoing conventional 2-stage IPG placement had an average follow-up of 31.8 months (range 8-48) compared with 38 months (range 5-57) for the children undergoing the modified 2-stage IPG placement. The total number of patients undergoing IPG placement was 27, with 19 (70%) undergoing our modified 2-stage procedure. Two of the patients failed to exhibit a minimal 50% improvement in symptoms after the first stage and therefore did not undergo IPG placement. The remaining 25 patients (93%) had a successful trial of SN and eventual IPG placement. Table 1 details the clinical information, including the number, age, and sex of the patients. The 2 groups were similar in terms of similar operative time for first-stage lead tunneling (⬍2 minutes), postopUROLOGY 73 (3), 2009
erative pain control (no intravenous narcotics), hospital stay (average 0.6 day), and interval between the first and second stage (approximately 25 days; Table 1; all P ⬎ .9). Differences were seen between the times of total radiation exposure in the second stage of the procedures (no fluoroscopy in the modified second stage), total first-stage incisions (none vs 2-3 in the modified vs conventional procedures, respectively), and incidence of postoperative infections (1 infection in the conventional 2-stage procedure; P ⫽ .333; Table 1). The 1 patient undergoing conventional 2-stage IPG placement who developed an infection at the site of implantation required device removal 4 months after IPG placement when a subcutaneous fluid collection was identified overlying the device. The fluid was aspirated, and bacterial culture was positive for coagulase-negative Staphylococcus. The IPG and lead were removed without difficulty. Although the long-term results of SN in children with medical refractory DES was outside the scope of this report and was recently reported for most children in our cohort,2 no obvious differences were found in the postoperative symptoms of the patients undergoing the modified or conventional procedure.
SN with the InterStim device in the pediatric population was shown in a multi-institutional report to have early success in children with DES.1 Recently, Roth et al.2 reported a rate of improvement or resolution of specific DES symptoms (ie, urinary incontinence, enuresis, urgency, frequency, retention, and/or constipation) of 25%-89% in the long-term follow-up of children undergoing SN with the InterStim device. This group of patients underwent SN after multiple medical therapies had failed, including different anticholinergic-based medications and behavioral therapy. SN placement in our patients was reserved for children with DES refractory to medical therapy for 2 reasons. First, the pediatric patient’s lower urinary tract symptoms might, in part, be a result of nerve immaturity, as alluded to by the 17% of adult women with “normal” lower urinary tract function reporting DES as children. Therefore, our group has encouraged children and their parents to allow a tincture of time using medical management to determine whether the patient improves. Second, we reserve a surgical procedure, with all its inherent risks to the child and monetary costs to the family, for patients still having symptoms despite maximal medical therapy. For those patients eventually undergoing SN, we have continually attempted to modify our procedure to better the child’s postoperative course without changing the outcomes. Our modifications to the well-known 2-stage SN implantation of the InterStim device have decreased the intraoperative radiation exposure and surgical incisions 643
while continuing to demonstrate tolerable postoperative pain, allowing our patients to be discharged the same day. The reduction in radiation exposure to the child by simply using a temporary methylene blue tattoo is reliable without its fading by the time of the second stage. The application of the ureteral sheath provides the surgeon with a longer and increased caliber dilator to allow for easier subcutaneous manipulation between 2 points with 1 stab wound, instead of 2 larger incisions. Although the cosmesis is obviously improved with a decreased number of skin disruptions, the comparison of the conventional and modified procedures found a decreased number of postoperative infections after the modified 2-stage SN implantation. Of the 8 patients in the conventional 2-stage SN implantation cohort, 1 (11%) required IPG explantation because of a postoperative infection involving the IPG implantation site (Table 1). Of the 19 patients who underwent our modified 2-stage SN implantation, none have had evidence of a postoperative infection. Although this represents only 1 of 27 total patients (4%) and was not a statistically significant difference (P ⫽ .333), this finding might allude to the ability of our modified procedure to decrease the incidence of postoperative infections. Larger series that use our modified 2-stage SN implantation are required to confirm whether our modification results in a decreased postoperative infection rate.
viously demonstrated by the authors,1 the implantation of a sacral neurostimulator can be effective in treating these children. The drawbacks of implanting this device include exposure to ionizing radiation, the presence of multiple incisions, and the risk of infection. In the present study, the authors make yet another contribution as they describe their experience implementing innovative modifications of the standard technique aimed at overcoming these shortcomings. Although they cannot eliminate the need for fluoroscopy in the first stage of the procedure, the need for subsequent fluoroscopy is obviated by the clever use of methylene blue at the site of the connector between the quadripolar tined lead and temporary external lead. They improve the cosmesis by limiting the number of incisions to the incision in the second stage of the procedure by using a ureteral access sheath for tunneling the wires in the first stage. This advance eliminates 1 incision for those in whom the device will remain and avoids any incision in those children in whom the device is ultimately not implanted. The risk of infection cannot be determined at this point. The authors should be congratulated for making strides in this arena and advancing the cause of both minimally invasive procedures and the treatment of the child with difficult dysfunctional elimination syndrome. Lane S. Palmer, M.D., Division of Pediatric Urology, Schneider Children’s Hospital, Lake Success, New York
Reference
CONCLUSIONS Our modified 2-stage SN device implantation procedure is technically simple and quick to perform and results in decreased radiation exposure, excellent pain control, and improved cosmesis, without compromising the outcomes. Larger series using the modified 2-stage SN implantation technique are required to confirm whether our modification has a decreased postoperative infection rate. References 1. Humphreys MR, Vandersteen DR, Slezak JM, et al. Preliminary results of sacral neuromodulation in 23 children. J Urol. 2006;176: 2227-2231. 2. Roth TJ, Vandersteen DR, Hollatz P, et al. Sacral neuromodulation in children with dysfunctional elimination syndrome: a single center experience in twenty children. J Urol. 2008;180:306-311. 3. Daneshgari F, Moy ML. Current indications for neuromodulation. Urol Clin North Am. 2005;32:37-40. 4. Bower WF, Yip SK, Yeung CK. Dysfunctional elimination symptoms in childhood and adulthood. J Urol. 2005;174:1623-1628. 5. Janknegt RA, Weil EHJ, Eerdmans PHA. Improving neuromodulation technique for refractory voiding dysfunctions: two-stage implant. Urology. 1997;49:358-362.
Video Clips cited in this article can be found on the internet at: http://www.goldjournal.net
EDITORIAL COMMENT The treatment of children with refractory dysfunctional elimination syndrome can be quite frustrating. Fortunately, as pre644
1. Roth TJ, Vandersteen DR, Hollatz P, et al. Sacral neuromodulation in children with dysfunctional elimination syndrome: a single center experience in twenty children. J Urol. 2008;180:306-311.
doi:10.1016/j.urology.2008.11.036 UROLOGY 73: 644, 2009. © 2009 Elsevier Inc.
REPLY Our experience now includes 41 children with dysfunctional elimination syndrome (DES) treated with sacral nerve stimulation, and we have seen no wound infections when using our modified procedure. Although this treatment modality has demonstrated its efficiency in treating very severe cases of DES (65%-90% improvement or resolution of urinary urgency, frequency, and incontinence) (unpublished data: Chavin GS, Rangel L, Hollatz P, et al. Sacral neuromodulation in children with dysfunctional elimination syndrome: a single center experience in forty-one children), we still advocate the use of sacral nerve stimulation in children in whom other medical treatments have previously not been successful as we gain longer term outcomes. Shawn M. McGee, M.D., Department of Urology, Mayo Medical School and Mayo Clinic, Rochester, Minnesota David R. Vandersteen, M.D., and Yuri Reinberg, M.D., Division of Urology, Children’s Hospital of Minnesota, Minneapolis, Minnesota doi:10.1016/j.urology.2008.12.002 UROLOGY 73: 644, 2009. © 2009 Elsevier Inc.
UROLOGY 73 (3), 2009
METHODS
RESULTS
CONCLUSIONS
To detail a percutaneous technique of sacral nerve neuromodulation (SN) that eliminates the first-stage incisions and the need for second-stage fluoroscopy. Our group has previously described the results of SN in children with medically refractory dysfunctional elimination syndrome. The drawbacks to SN include the use of fluoroscopy and the need to reopen recent skin incisions during the second stage. This results in increased radiation exposure, poor cosmesis, and possible wound infection. The incisionless first stage consisted of percutaneously tunneling the temporary external appliance to the contralateral axillary line at the buttock after localization of the S3 nerve root and placement of a quadripolar tined lead under fluoroscopic guidance. A subcutaneous bolus of methylene blue marked the lead connector site, obviating the need for later fluoroscopic localization to place the implantable pulse generator at the second stage. A total of 27 children with refractory dysfunctional elimination syndrome underwent SN using the InterStim device. Of the 27 patients, 19 underwent our modified technique. The operative time for our modified tunneling and placement technique was ⱕ2 minutes. The mean hospital stay was 0.6 day, with no patient requiring postoperative intravenous narcotics. At a mean follow-up of 35.9 months, no wound infections had occurred in the incisionless cohort compared with 1 postoperative wound infection requiring device explantation in the conventional lead placement group. The incisionless technique of SN device implantation is technically simple, quick to perform, and results in decreased radiation exposure, excellent pain control, and improved cosmesis without compromising the outcomes. UROLOGY 73: 641– 644, 2009. © 2009 Elsevier Inc.
S
acral nerve neuromodulation (SN) with the InterStim device (Medtronic, Minneapolis, MN) has been successfully applied to children with medically refractory dysfunction elimination syndrome (DES).1,2 DES is a constellation of chronic urinary symptoms that can be especially frustrating to the child, parents, and medical caregivers owing to the frequent evaluations and numerous medical therapies. Despite the initial success seen with the InterStim in the pediatric population, SN is currently reserved for children with DES who do not respond to conventional therapy such as medications and behavior modification. SN is an established Food and Drug Administrationapproved treatment for chronic urge incontinence, uriFrom the Department of Urology, Mayo Medical School and Mayo Clinic, Rochester, Minnesota; and Division of Urology, Children’s Hospital of Minnesota, Minneapolis, Minnesota Reprint requests: Shawn M. McGee, M.D., Department of Urology, Mayo Clinic, 200 First Street Southwest, Rochester MN 55905. E-mail: [email protected] Submitted: September 10, 2008, accepted (with revisions): October 27, 2008
© 2009 Elsevier Inc. All Rights Reserved
nary urgency, frequency, and nonobstructive urinary retention in adults.3 Previously, 12%-25% of women with dysfunctional elimination symptoms had admitted to DES-type symptoms as children.4 These chronic underlying lower urinary tract symptoms beginning in childhood have some investigators surmising that more aggressive diagnosis and treatment of DES in children might avert progressive dysfunctional elimination symptoms into adolescence. As such, small cohorts of children with debilitating and refractory DES have undergone SN in an attempt to alleviate their current symptoms and possibly future lower urinary tract dysfunction. As with all therapies and surgical procedures applied to patients, attempts have been made to use minimally invasive techniques to improve cosmesis and decrease pain and subsequent hospitalization time. This is especially true in the pediatric population. In addition, pediatric caregivers have strived to lessen children’s exposure to radiation to avert the increased risk of delayed development and possible malignancy. We report a modifica0090-4295/09/$34.00 doi:10.1016/j.urology.2008.10.067
641
tion to the 2-stage InterStim device implantation that eliminates the large surgical incisions and fluoroscopic exposure in children.
MATERIAL AND METHODS Patients With institutional review board approval, we evaluated 27 patients, including 18 girls and 9 boys with a mean age of 10.1 years (range 6-17) after SN with the InterStim (Medtronic) implantable device from December 2002 to March 2007. The children in the study had had no neurologic abnormalities and had previously been diagnosed with DES. The children were considered for SN only if they had remained symptomatic after 6 months of maximal medical management, including behavioral modification, timed voiding and defecation, biofeedback, and multiple pharmacologic therapies. The decision to proceed with SN was made by the individual patient and caregiver on a case by case basis.
Conventional 2-Stage Implanted Pulse Generator Placement The 2 stages of the procedure were performed at a single institution by 1 of 2 surgeons (Y.E.R. or D.R.V.). Prophylactic intravenous antibiotics were given to all patients before both stages. During the conventional first stage of SN implantation, percutaneous transforaminal access to the third sacral spinal nerve (S3) was achieved, and, once an appropriate neurologic response was elicited, a quadripolar tined lead was implanted. Before developing the incisionless first-stage technique, the extender leads of the temporary external neurostimulator device were subcutaneously tunneled laterally from the sacrum to one side of the patient and then to the contralateral side, after creating an incision, as previously described by Janknegt et al.5 The external neurostimulator device was then left in the patient for 2-6 weeks as a trial period. The second stage of the SN implantation was performed on patients who demonstrated a ⱖ50% improvement in voiding dysfunction during the trial period. During the conventional second stage, fluoroscopy was again used to locate the subcutaneous extender leads and connector before making an incision in the same location at which the previous gluteal incision was made in the first stage of the SN implantation. The implanted pulse generator (IPG) was then placed into a pocket created under the previous gluteal incision. All incisions were then closed with subcutaneous suturing.
Modified 2-Stage IPG Placement: Incisionless First Stage The incisionless first stage of SN implantation was performed at a single institution by the same surgeons who performed conventional IPG placement. Prophylactic intravenous antibiotics were given to all patients before both stages. During the incisionless first stage, percutaneous transforaminal access to the third sacral spinal nerve (S3) was achieved with fluoroscopy, as done with the conventional first stage. Once the appropriate neurologic response was elicited, a quadripolar tined lead was implanted. Unlike in the conventional technique, the extender leads of the temporary external neurostimulator device were subcutaneously tunneled laterally to the axillary line of the patient with a commercially available 14F ureteral access sheath applied 642
Figure 1. Temporary external lead exits child laterally at axillary line of patient after dilation of tract with commercially available 14F ureteral access sheath. Methylene tattoo marks connection to external lead (square along lead).
through the percutaneous site at which the quadripolar tined lead exited the skin (Fig. 1 and Video). The ureteral access sheath exited the patient’s skin laterally at the level of the gluteal cleft through a small stab wound (Fig. 1 and Video). The quadripolar tined lead and temporary external lead were then advanced through the ureteral access sheath laterally to the axillary line of the patient. After placing the quadripolar tined lead and temporary external lead through the subcutaneous tract, the eventual site of the permanent IPG was marked with methylene blue as a temporary tattoo at the site of the connector between the quadripolar tined lead and the temporary external lead on the patient’s gluteal region (Fig. 2 and Video). This step obviated the surgeon’s need to use fluoroscopy during the second stage when the permanent IPG was placed. The percutaneous site and lateral stab wound were closed with dermal bonding adhesive.
Modified 2-Stage IPG Placement: Second-Stage Without Fluoroscopy During the second stage of the IPG placement, fluoroscopy was not used throughout the procedure, secondary to the previously created methylene blue tattoo at the location of the eventual incision for IPG placement. At this point, the patient underwent a novel 4-5-cm incision over the location of the methylene blue tattoo to place the permanent IPG (Fig. 2). The incision was then closed with subcutaneous suturing.
Statistical Analysis The clinical features of interest were compared between the children undergoing our modified 2-stage procedure and those who underwent the conventional 2-stage procedure using the 2 or Fischer’s exact test, as appropriate. All tests were 2-sided, with P ⬍ .05 considered statistically significant. UROLOGY 73 (3), 2009
Figure 2. Final location of implanted pulse generator using our modified technique. Table 1. Clinical features
COMMENT
Variable
Total
Patients (n) Sex Female Male Age (y) Average Range Average interval between stages (d) Infection after placement (n)
27
9
18
19 8
7 2
12 6
Conventional
Incisionless
10.1 6-17 25.5
7 7-14 25.9
10 6-17 25.4
1 (3.7)
1 (11)
0
Data in parentheses are percentages.
RESULTS The average follow-up was 35.9 months (range 5-57) for all children undergoing IPG placement. Children undergoing conventional 2-stage IPG placement had an average follow-up of 31.8 months (range 8-48) compared with 38 months (range 5-57) for the children undergoing the modified 2-stage IPG placement. The total number of patients undergoing IPG placement was 27, with 19 (70%) undergoing our modified 2-stage procedure. Two of the patients failed to exhibit a minimal 50% improvement in symptoms after the first stage and therefore did not undergo IPG placement. The remaining 25 patients (93%) had a successful trial of SN and eventual IPG placement. Table 1 details the clinical information, including the number, age, and sex of the patients. The 2 groups were similar in terms of similar operative time for first-stage lead tunneling (⬍2 minutes), postopUROLOGY 73 (3), 2009
erative pain control (no intravenous narcotics), hospital stay (average 0.6 day), and interval between the first and second stage (approximately 25 days; Table 1; all P ⬎ .9). Differences were seen between the times of total radiation exposure in the second stage of the procedures (no fluoroscopy in the modified second stage), total first-stage incisions (none vs 2-3 in the modified vs conventional procedures, respectively), and incidence of postoperative infections (1 infection in the conventional 2-stage procedure; P ⫽ .333; Table 1). The 1 patient undergoing conventional 2-stage IPG placement who developed an infection at the site of implantation required device removal 4 months after IPG placement when a subcutaneous fluid collection was identified overlying the device. The fluid was aspirated, and bacterial culture was positive for coagulase-negative Staphylococcus. The IPG and lead were removed without difficulty. Although the long-term results of SN in children with medical refractory DES was outside the scope of this report and was recently reported for most children in our cohort,2 no obvious differences were found in the postoperative symptoms of the patients undergoing the modified or conventional procedure.
SN with the InterStim device in the pediatric population was shown in a multi-institutional report to have early success in children with DES.1 Recently, Roth et al.2 reported a rate of improvement or resolution of specific DES symptoms (ie, urinary incontinence, enuresis, urgency, frequency, retention, and/or constipation) of 25%-89% in the long-term follow-up of children undergoing SN with the InterStim device. This group of patients underwent SN after multiple medical therapies had failed, including different anticholinergic-based medications and behavioral therapy. SN placement in our patients was reserved for children with DES refractory to medical therapy for 2 reasons. First, the pediatric patient’s lower urinary tract symptoms might, in part, be a result of nerve immaturity, as alluded to by the 17% of adult women with “normal” lower urinary tract function reporting DES as children. Therefore, our group has encouraged children and their parents to allow a tincture of time using medical management to determine whether the patient improves. Second, we reserve a surgical procedure, with all its inherent risks to the child and monetary costs to the family, for patients still having symptoms despite maximal medical therapy. For those patients eventually undergoing SN, we have continually attempted to modify our procedure to better the child’s postoperative course without changing the outcomes. Our modifications to the well-known 2-stage SN implantation of the InterStim device have decreased the intraoperative radiation exposure and surgical incisions 643
while continuing to demonstrate tolerable postoperative pain, allowing our patients to be discharged the same day. The reduction in radiation exposure to the child by simply using a temporary methylene blue tattoo is reliable without its fading by the time of the second stage. The application of the ureteral sheath provides the surgeon with a longer and increased caliber dilator to allow for easier subcutaneous manipulation between 2 points with 1 stab wound, instead of 2 larger incisions. Although the cosmesis is obviously improved with a decreased number of skin disruptions, the comparison of the conventional and modified procedures found a decreased number of postoperative infections after the modified 2-stage SN implantation. Of the 8 patients in the conventional 2-stage SN implantation cohort, 1 (11%) required IPG explantation because of a postoperative infection involving the IPG implantation site (Table 1). Of the 19 patients who underwent our modified 2-stage SN implantation, none have had evidence of a postoperative infection. Although this represents only 1 of 27 total patients (4%) and was not a statistically significant difference (P ⫽ .333), this finding might allude to the ability of our modified procedure to decrease the incidence of postoperative infections. Larger series that use our modified 2-stage SN implantation are required to confirm whether our modification results in a decreased postoperative infection rate.
viously demonstrated by the authors,1 the implantation of a sacral neurostimulator can be effective in treating these children. The drawbacks of implanting this device include exposure to ionizing radiation, the presence of multiple incisions, and the risk of infection. In the present study, the authors make yet another contribution as they describe their experience implementing innovative modifications of the standard technique aimed at overcoming these shortcomings. Although they cannot eliminate the need for fluoroscopy in the first stage of the procedure, the need for subsequent fluoroscopy is obviated by the clever use of methylene blue at the site of the connector between the quadripolar tined lead and temporary external lead. They improve the cosmesis by limiting the number of incisions to the incision in the second stage of the procedure by using a ureteral access sheath for tunneling the wires in the first stage. This advance eliminates 1 incision for those in whom the device will remain and avoids any incision in those children in whom the device is ultimately not implanted. The risk of infection cannot be determined at this point. The authors should be congratulated for making strides in this arena and advancing the cause of both minimally invasive procedures and the treatment of the child with difficult dysfunctional elimination syndrome. Lane S. Palmer, M.D., Division of Pediatric Urology, Schneider Children’s Hospital, Lake Success, New York
Reference
CONCLUSIONS Our modified 2-stage SN device implantation procedure is technically simple and quick to perform and results in decreased radiation exposure, excellent pain control, and improved cosmesis, without compromising the outcomes. Larger series using the modified 2-stage SN implantation technique are required to confirm whether our modification has a decreased postoperative infection rate. References 1. Humphreys MR, Vandersteen DR, Slezak JM, et al. Preliminary results of sacral neuromodulation in 23 children. J Urol. 2006;176: 2227-2231. 2. Roth TJ, Vandersteen DR, Hollatz P, et al. Sacral neuromodulation in children with dysfunctional elimination syndrome: a single center experience in twenty children. J Urol. 2008;180:306-311. 3. Daneshgari F, Moy ML. Current indications for neuromodulation. Urol Clin North Am. 2005;32:37-40. 4. Bower WF, Yip SK, Yeung CK. Dysfunctional elimination symptoms in childhood and adulthood. J Urol. 2005;174:1623-1628. 5. Janknegt RA, Weil EHJ, Eerdmans PHA. Improving neuromodulation technique for refractory voiding dysfunctions: two-stage implant. Urology. 1997;49:358-362.
Video Clips cited in this article can be found on the internet at: http://www.goldjournal.net
EDITORIAL COMMENT The treatment of children with refractory dysfunctional elimination syndrome can be quite frustrating. Fortunately, as pre644
1. Roth TJ, Vandersteen DR, Hollatz P, et al. Sacral neuromodulation in children with dysfunctional elimination syndrome: a single center experience in twenty children. J Urol. 2008;180:306-311.
doi:10.1016/j.urology.2008.11.036 UROLOGY 73: 644, 2009. © 2009 Elsevier Inc.
REPLY Our experience now includes 41 children with dysfunctional elimination syndrome (DES) treated with sacral nerve stimulation, and we have seen no wound infections when using our modified procedure. Although this treatment modality has demonstrated its efficiency in treating very severe cases of DES (65%-90% improvement or resolution of urinary urgency, frequency, and incontinence) (unpublished data: Chavin GS, Rangel L, Hollatz P, et al. Sacral neuromodulation in children with dysfunctional elimination syndrome: a single center experience in forty-one children), we still advocate the use of sacral nerve stimulation in children in whom other medical treatments have previously not been successful as we gain longer term outcomes. Shawn M. McGee, M.D., Department of Urology, Mayo Medical School and Mayo Clinic, Rochester, Minnesota David R. Vandersteen, M.D., and Yuri Reinberg, M.D., Division of Urology, Children’s Hospital of Minnesota, Minneapolis, Minnesota doi:10.1016/j.urology.2008.12.002 UROLOGY 73: 644, 2009. © 2009 Elsevier Inc.
UROLOGY 73 (3), 2009