Objective To observe the effect of acupuncture stimulation of the sacral segment on the excitability of the cerebral cortex and the activity of the urinary bladder and the involvement of the cholinergic neurons in the...Objective To observe the effect of acupuncture stimulation of the sacral segment on the excitability of the cerebral cortex and the activity of the urinary bladder and the involvement of the cholinergic neurons in the laterodorsal tegmental (LDT) nucleus of the brainstem in acupuncture-induced electroencephalogram (EEG) changes. Methods A total of 109 SD rats were used in the present study. Under anesthesia (urethane), a pair of stainless steel electrodes was separately implanted into the frontal and parietal bony sutures to record EEG. Glass microelectrodes were used to record extracellular discharges of single neuron of the LDT nucleus in the brainstem. Urinary bladder pressure was recorded through a catheter inserted in the bladder and the contraction was induced by infusion of normal saline. A filiform acupuncture needle was inserted into the sacral segment Ecorresponding to Zhongliao (中髎BL 33)] and rotated manually for 1 min. Results In 27 rats whose bladder was full of normal saline, acupuncture stimulation of the sacral region suppressed the contraction activity of the bladder, the fast EEG with lower amplitude and higher frequency tuned into slow EEG with higher amplitude and lower frequency in 6 cases (22.2%). The inhibitory effect occurred from 45 s to 12 min after acupuncture manipulation. In 82 rats whose bladder was empty, acupuncture stimulation caused the fast EEG to turn into slow EEG in 71 cases (86.6%). Simultaneously, LDT cholinergic neurons reduced their firing rates from (2.9±1.5) Hz to (1.2±0.6) Hz (n = 12, P〈0.05), and the reduction of LDT neuronal discharge was earlier in time than the change of EEG. Conclusion Acupuncture stimulation of the sacral region can lower the excitability of the cerebral cortex and suppress bladder activity, which is closely associated with its resultant inhibitory effect on the electrical activity of LDT cholinergic neurons.展开更多
U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently c...U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or (and) sacral decompression. EQ-5d score was applied to evaluate the patients' quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years (range: 15-55 years) at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months (range: 9-47 months) and mean full weight-bearing time was 9.9 weeks (range: 8-14 weeks). Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle (mean 27.87°, and range: 8°-90°) of the sacrum was smaller than that pre-operation (mean 35.67; range: 15-90) with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score (VAS) was reduced from preoperative 7.07 (range: 5-9) to postoperetive 1.93 (range: 1-3). All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.展开更多
The sacral nerve anterior root consists of parasympathetic nerves(dominating urinary bladder detrusor)and somatic motor nerves(dominating urethral sphincter),and electrical stimulation to the sacral nerve anterior...The sacral nerve anterior root consists of parasympathetic nerves(dominating urinary bladder detrusor)and somatic motor nerves(dominating urethral sphincter),and electrical stimulation to the sacral nerve anterior root induces simultaneous contraction of the bladder detrusor and urethral sphincter.Accordingly,urethral pressure exceeds intravesical pressure,resulting in little or no urination,kidney damage,and trembling of lower limbs due to high intravesical pressure.In the present study,sacral nerve posterior roots were transected in a spastic bladder rabbit model,followed by three-pole electrode and long-pulse electrical stimulation to the sacral anterior root.Intravesical and urethral pressures were simultaneously measured to verify the feasibility of anode inhibition to the sacral anterior root following induced detrusor contraction.As stimulus intensity increased,somatic motor nerves were increasingly inhibited; with a stimulus pulse width of 300 μs and stimulus current of 1.05 mA,urethral pressure was zero and average intravesical pressure was 3.84 kPa.In addition,detrusor contraction was displayed,and lower extremity trembling was significantly reduced.Three-pole electrode and long-pulse electrical stimulation to the sacral nerve anterior root induced detrusor contraction and inhibited low extremity trembling under electrical stimulation.展开更多
Sacral fractures following posterior lumbosacral fusion are an uncommon complication. Only a few case series and case reports have been published so far. This article presents a case of totally displaced sacral fractu...Sacral fractures following posterior lumbosacral fusion are an uncommon complication. Only a few case series and case reports have been published so far. This article presents a case of totally displaced sacral fracture following posterior L4-S1 fusion in a 65-yearold patient with a 15-year history of corticosteroid use who underwent open reduction and internal fixation using iliac screws. The patient was followed for 2 years. A thorough review of the literature was conducted using the Medline database between 1994 and 2014. Immediately after the revision surgery, the patient's pain in the buttock and left leg resolved significantly. The patient was followed for 2 years. The weakness in the left lower extremity improved gradually from 3/5 to 5/5. In conclusion, the incidence of postoperative sacral fractures could have been underestimated, because most of these fractures are not visible on a plain radiograph. Computed tomography has been proved to be able to detect most such fractures and should probably be performed routinely when patients complain of renewed buttock pain within 3 mo after lumbosacral fusion. The majority of the patients responded well to conservative treatments, and extending the fusion construct to the iliac wings using iliac screws may be needed when there is concurrent fracture displacement, sagittal imbalance, neurologic symptoms, or painful nonunion.展开更多
The role of sphincteroplasty in the treatment of patients with fecal incontinence due to anal sphincter defects has been questioned because the success rate declines in the long-term.A new emerging treatment for fecal...The role of sphincteroplasty in the treatment of patients with fecal incontinence due to anal sphincter defects has been questioned because the success rate declines in the long-term.A new emerging treatment for fecal incontinence,sacral nerve stimulation,has been shown to be effective in these patients.However,the success rate of sphincteroplasty may depend of several patient-related and surgical-related factors and the outcome from sphincteroplasty has been evaluated differently(with qualitative data) from that after sacral nerve stimulation(quantitative data using scoring systems and quality of life).Furthermore,the data available so far on the longterm success rate after sacral nerve modulation do not differ substantially from those after sphincteroplasty.The actual data do not support the replacement of sphincteroplasty with sacral nerve stimulation in patients with fecal incontinence secondary to sphincter defects.展开更多
To analyze the anatomy of sacral venous plexus flow, the causes of injuries and the methods for controlling presacral hemorrhage during surgery for rectal cancer.METHODSA review of the databases MEDLINE<sup>...To analyze the anatomy of sacral venous plexus flow, the causes of injuries and the methods for controlling presacral hemorrhage during surgery for rectal cancer.METHODSA review of the databases MEDLINE<sup>®</sup> and Embase™ was conducted, and relevant scientific articles published between January 1960 and June 2016 were examined. The anatomy of the sacrum and its venous plexus, as well as the factors that influence bleeding, the causes of this complication, and its surgical management were defined.RESULTSThis is a review of 58 published articles on presacral venous plexus injury during the mobilization of the rectum and on techniques used to treat presacral venous bleeding. Due to the lack of cases published in the literature, there is no consensus on which is the best technique to use if there is presacral bleeding during mobilization in surgery for rectal cancer. This review may provide a tool to help surgeons make decisions regarding how to resolve this serious complication.CONCLUSIONA series of alternative treatments are described; however, a conventional systematic review in which optimal treatment is identified could not be performed because few cases were analyzed in most publications.展开更多
AIM:To investigate the nature and severity of AE related to sacral neurostimulation(SNS).METHODS:Based on Pubmed and Embase searches,we identified published trials and case series of SNS for fecal incontinence(FI)and ...AIM:To investigate the nature and severity of AE related to sacral neurostimulation(SNS).METHODS:Based on Pubmed and Embase searches,we identified published trials and case series of SNS for fecal incontinence(FI)and extracted data on adverse events,requiring an active intervention.Those problems were operationally defined as infection,device removal explant or need for lead and/or generator replacement.In addition,we analyzed the Manufacturer and User Device Experience registry of the Federal Drug Administration for the months of August-October of2015.Events were included if the report specifically mentioned gastrointestinal(GI),bowel and FI as indication and if the narrative did not focus on bladder symptoms.The classification,reporter,the date of the recorded complaint,time between initial implant and report,the type of AE,steps taken and outcome were extracted from the report.In cases of device removal or replacement,we looked for confirmatory comments by healthcare providers or the manufacturer.RESULTS:Published studies reported adverse events and reoperation rates for 1954 patients,followed for 27(1-117)mo.Reoperation rates were 18.6%(14.2-23.9)with device explants accounting for 10.0%(7.8-12.7)of secondary surgeries;rates of device replacement or explant or pocket site and electrode revisions increased with longer follow up.During the period examined,the FDA received 1684 reports of AE related to SNS with FI or GI listed as indication.A total of 652 reports met the inclusion criteria,with 52.7%specifically listing FI.Lack or loss of benefit(48.9%),pain or dysesthesia(27.8%)and complication at the generator implantation site(8.7%)were most commonly listed.Complaints led to secondary surgeries in 29.7%of the AE.Reoperations were performed to explant(38.2%)or replace(46.5%)the device or a lead,or revise the generator pocket(14.6%).Conservative management changes mostly involved changes in stimulation parameters(44.5%),which successfully addressed concerns in 35.2%of cases that included information about treatment results.CONCLUSION:With reoperation rates around 20%,physicians need to fully disclose the high likelihood ofcomplications and secondary interventions and exhaust non-invasive treatments,including transcutaneous stimulation paradigms.展开更多
Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode b...Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root re- mains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9_10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimu- lation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation.展开更多
AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord...AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries. METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots. RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1(11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1(14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device. CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.展开更多
文摘Objective To observe the effect of acupuncture stimulation of the sacral segment on the excitability of the cerebral cortex and the activity of the urinary bladder and the involvement of the cholinergic neurons in the laterodorsal tegmental (LDT) nucleus of the brainstem in acupuncture-induced electroencephalogram (EEG) changes. Methods A total of 109 SD rats were used in the present study. Under anesthesia (urethane), a pair of stainless steel electrodes was separately implanted into the frontal and parietal bony sutures to record EEG. Glass microelectrodes were used to record extracellular discharges of single neuron of the LDT nucleus in the brainstem. Urinary bladder pressure was recorded through a catheter inserted in the bladder and the contraction was induced by infusion of normal saline. A filiform acupuncture needle was inserted into the sacral segment Ecorresponding to Zhongliao (中髎BL 33)] and rotated manually for 1 min. Results In 27 rats whose bladder was full of normal saline, acupuncture stimulation of the sacral region suppressed the contraction activity of the bladder, the fast EEG with lower amplitude and higher frequency tuned into slow EEG with higher amplitude and lower frequency in 6 cases (22.2%). The inhibitory effect occurred from 45 s to 12 min after acupuncture manipulation. In 82 rats whose bladder was empty, acupuncture stimulation caused the fast EEG to turn into slow EEG in 71 cases (86.6%). Simultaneously, LDT cholinergic neurons reduced their firing rates from (2.9±1.5) Hz to (1.2±0.6) Hz (n = 12, P〈0.05), and the reduction of LDT neuronal discharge was earlier in time than the change of EEG. Conclusion Acupuncture stimulation of the sacral region can lower the excitability of the cerebral cortex and suppress bladder activity, which is closely associated with its resultant inhibitory effect on the electrical activity of LDT cholinergic neurons.
文摘U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or (and) sacral decompression. EQ-5d score was applied to evaluate the patients' quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years (range: 15-55 years) at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months (range: 9-47 months) and mean full weight-bearing time was 9.9 weeks (range: 8-14 weeks). Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle (mean 27.87°, and range: 8°-90°) of the sacrum was smaller than that pre-operation (mean 35.67; range: 15-90) with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score (VAS) was reduced from preoperative 7.07 (range: 5-9) to postoperetive 1.93 (range: 1-3). All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.
基金a grant for International Cooperation Project by Jilin Provincial Science and Technology Commission,No.20100735
文摘The sacral nerve anterior root consists of parasympathetic nerves(dominating urinary bladder detrusor)and somatic motor nerves(dominating urethral sphincter),and electrical stimulation to the sacral nerve anterior root induces simultaneous contraction of the bladder detrusor and urethral sphincter.Accordingly,urethral pressure exceeds intravesical pressure,resulting in little or no urination,kidney damage,and trembling of lower limbs due to high intravesical pressure.In the present study,sacral nerve posterior roots were transected in a spastic bladder rabbit model,followed by three-pole electrode and long-pulse electrical stimulation to the sacral anterior root.Intravesical and urethral pressures were simultaneously measured to verify the feasibility of anode inhibition to the sacral anterior root following induced detrusor contraction.As stimulus intensity increased,somatic motor nerves were increasingly inhibited; with a stimulus pulse width of 300 μs and stimulus current of 1.05 mA,urethral pressure was zero and average intravesical pressure was 3.84 kPa.In addition,detrusor contraction was displayed,and lower extremity trembling was significantly reduced.Three-pole electrode and long-pulse electrical stimulation to the sacral nerve anterior root induced detrusor contraction and inhibited low extremity trembling under electrical stimulation.
文摘Sacral fractures following posterior lumbosacral fusion are an uncommon complication. Only a few case series and case reports have been published so far. This article presents a case of totally displaced sacral fracture following posterior L4-S1 fusion in a 65-yearold patient with a 15-year history of corticosteroid use who underwent open reduction and internal fixation using iliac screws. The patient was followed for 2 years. A thorough review of the literature was conducted using the Medline database between 1994 and 2014. Immediately after the revision surgery, the patient's pain in the buttock and left leg resolved significantly. The patient was followed for 2 years. The weakness in the left lower extremity improved gradually from 3/5 to 5/5. In conclusion, the incidence of postoperative sacral fractures could have been underestimated, because most of these fractures are not visible on a plain radiograph. Computed tomography has been proved to be able to detect most such fractures and should probably be performed routinely when patients complain of renewed buttock pain within 3 mo after lumbosacral fusion. The majority of the patients responded well to conservative treatments, and extending the fusion construct to the iliac wings using iliac screws may be needed when there is concurrent fracture displacement, sagittal imbalance, neurologic symptoms, or painful nonunion.
文摘The role of sphincteroplasty in the treatment of patients with fecal incontinence due to anal sphincter defects has been questioned because the success rate declines in the long-term.A new emerging treatment for fecal incontinence,sacral nerve stimulation,has been shown to be effective in these patients.However,the success rate of sphincteroplasty may depend of several patient-related and surgical-related factors and the outcome from sphincteroplasty has been evaluated differently(with qualitative data) from that after sacral nerve stimulation(quantitative data using scoring systems and quality of life).Furthermore,the data available so far on the longterm success rate after sacral nerve modulation do not differ substantially from those after sphincteroplasty.The actual data do not support the replacement of sphincteroplasty with sacral nerve stimulation in patients with fecal incontinence secondary to sphincter defects.
文摘To analyze the anatomy of sacral venous plexus flow, the causes of injuries and the methods for controlling presacral hemorrhage during surgery for rectal cancer.METHODSA review of the databases MEDLINE<sup>®</sup> and Embase™ was conducted, and relevant scientific articles published between January 1960 and June 2016 were examined. The anatomy of the sacrum and its venous plexus, as well as the factors that influence bleeding, the causes of this complication, and its surgical management were defined.RESULTSThis is a review of 58 published articles on presacral venous plexus injury during the mobilization of the rectum and on techniques used to treat presacral venous bleeding. Due to the lack of cases published in the literature, there is no consensus on which is the best technique to use if there is presacral bleeding during mobilization in surgery for rectal cancer. This review may provide a tool to help surgeons make decisions regarding how to resolve this serious complication.CONCLUSIONA series of alternative treatments are described; however, a conventional systematic review in which optimal treatment is identified could not be performed because few cases were analyzed in most publications.
文摘AIM:To investigate the nature and severity of AE related to sacral neurostimulation(SNS).METHODS:Based on Pubmed and Embase searches,we identified published trials and case series of SNS for fecal incontinence(FI)and extracted data on adverse events,requiring an active intervention.Those problems were operationally defined as infection,device removal explant or need for lead and/or generator replacement.In addition,we analyzed the Manufacturer and User Device Experience registry of the Federal Drug Administration for the months of August-October of2015.Events were included if the report specifically mentioned gastrointestinal(GI),bowel and FI as indication and if the narrative did not focus on bladder symptoms.The classification,reporter,the date of the recorded complaint,time between initial implant and report,the type of AE,steps taken and outcome were extracted from the report.In cases of device removal or replacement,we looked for confirmatory comments by healthcare providers or the manufacturer.RESULTS:Published studies reported adverse events and reoperation rates for 1954 patients,followed for 27(1-117)mo.Reoperation rates were 18.6%(14.2-23.9)with device explants accounting for 10.0%(7.8-12.7)of secondary surgeries;rates of device replacement or explant or pocket site and electrode revisions increased with longer follow up.During the period examined,the FDA received 1684 reports of AE related to SNS with FI or GI listed as indication.A total of 652 reports met the inclusion criteria,with 52.7%specifically listing FI.Lack or loss of benefit(48.9%),pain or dysesthesia(27.8%)and complication at the generator implantation site(8.7%)were most commonly listed.Complaints led to secondary surgeries in 29.7%of the AE.Reoperations were performed to explant(38.2%)or replace(46.5%)the device or a lead,or revise the generator pocket(14.6%).Conservative management changes mostly involved changes in stimulation parameters(44.5%),which successfully addressed concerns in 35.2%of cases that included information about treatment results.CONCLUSION:With reoperation rates around 20%,physicians need to fully disclose the high likelihood ofcomplications and secondary interventions and exhaust non-invasive treatments,including transcutaneous stimulation paradigms.
基金supported by the International Cooperation Projects of Jilin Province Science and Technology Commission,No.20100735
文摘Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root re- mains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9_10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimu- lation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation.
基金Supported by the National Science Fundation of China, No. 30440058
文摘AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries. METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots. RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1(11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1(14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device. CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.