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Int J Surg Case Rep
Int J Surg Case Rep
International Journal of Surgery Case Reports
2210-2612
Elsevier

S2210-2612(24)01000-9
10.1016/j.ijscr.2024.110219
110219
Case Report
Fever associated with machine activation after sacral neuromodulation: Case report
Zhao Jialei
Chen Gang gangchen@hospital.cqmu.edu.cn
⁎
Department of Urology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
⁎ Corresponding author. gangchen@hospital.cqmu.edu.cn
03 9 2024
10 2024
03 9 2024
123 11021929 6 2024
20 8 2024
25 8 2024
© 2024 The Authors. Published by Elsevier Ltd on behalf of IJS Publishing Group Limited.
2024

https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction and importance

Sacral neuromodulation (SNM) is commonly used in the treatment of refractory overactive bladder (OAB), non-obstructive urinary retention (NOR) and fecal incontinence. Here, we report an atypical symptomatic case to enrich the limited international case series.

Case presentation

We report a case of a male patient with cauda equina nerve injury left over from a traumatic injury and dysfunction of urinary and fecal functions who, after undergoing phase I sacral nerve stimulator placement, developed fever when the machine was switched on, and the symptoms resolved when it was switched off.

Clinical discussion

Sacral neuromodulation (SNM) is commonly used in the treatment of refractory overactive bladder (OAB), non-obstructive urinary retention (NOR) and fecal incontinence. The patient did not develop a non-infectious fever after the injury, only after the SNM device was installed and activated, and the temperature returned to normal after shutdown. We hypothesize that on top of the patient's pre-existing nerve damage and disorders, the activation of the SNM somehow stimulated the relevant sites, causing the patient to develop a neurogenic fever.

Conclusion

We concluded that in this case, it is reasonable to consider that the patient's fever was closely related to the placement of the sacral nerve stimulator.

Highlights

• Patient develops fever during device startup.

• Patient had a cauda equina injury.

• The mechanism of action of Sacral neuromodulation is still unclear.

• The fever may have been caused by irritation of the injured nerve when Sacral neuromodulation was turned on.

Keywords

Sacral neuromodulation
Fever
Complications
Case
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pmc1 Introduction

Sacral neuromodulation (SNM) is a widely accepted treatment for a wide range of lower urinary tract dysfunctions. The mechanism of SNM is not fully understood, and is primarily based on mild electrical stimulation of the sacral nerves to modulate bladder and pelvic floor reflexes. Refractory overactive bladder (OAB), non-obstructive urinary retention (NOR) and fecal incontinence are indications for SNM. The most common adverse events include implant site pain, paresthesia, altered sensation of irritation, and infection. Unexplained postoperative fever is a problem, and we report a case of device-related fever after sacral neuromodulation. The work has been reported in line with the SCARE criteria [1].

2 Presentation of the case

A 57-year-old Asian male with splenic rupture, lumbar spine fracture and multiple rib fractures due to a fall from a height of 10 m 8 months ago underwent splenectomy, internal fixation of rib fracture and internal fixation of lumbar spine fracture in a local hospital, after which he presented with dysfunction of bladder and bowel and reduced muscle strength of the lower limbs, and was considered to have cauda equina injury (Fig. 1). Afterwards, he was catheterised.Fig. 1 Preoperative digital radiography of the chest: a. crown plane b. sagittal plane.

Fig. 1

He was hospitalized in the rehabilitation unit 4 months ago for 3 months. During his hospitalization, the rehabilitation physician used tamsulosin (0.2 mg qd), solifenacin (5 mg qd), finasteride (5 mg qd) to improve lower urinary tract symptoms, methylcobalamin (0.5 mg tid) for nerve nutrition, wrist and ankle needling and sacrococcygeal electro-acupuncture for rehabilitation, and bladder function training. During this treatment period recurrent bilateral pain around the buttocks and mild-moderate pain in the sacrococcygeal area were considered to be neurologic complex regional pain, and the analgesic drug pregabalin (75 mg q12h) was used to control the symptoms. The medication did not work for the patient, who was discharged from the hospital and discontinued the medication and remained on a catheter for urinary catheterisation. At baseline, he reported complete absence of bowel and urinary urges, grade 4 muscle strength in hip flexors, knee extensors, ankle dorsiflexors, bunion extensors, and ankle-toe dorsiflexors of both lower extremities, and bilateral hyporeflexia of the ankle reflexes and knee reflexes. The patient underwent a preoperative pelvic CT plain, and the CT allowed visualization of a small diverticulum in the anterior wall of the bladder, measuring approximately 11 × 6 mm, with no significant abnormalities seen in the rest of the structures. The patient underwent staged SNS implantation (Medtronic®) with a needle placed into the right S3 hole with parameters set at 14 Hz, 210 μsec (Fig. 2). This stage of the procedure was performed in the operating theatre under aseptic conditions; the patient received povidone‑iodine solution to disinfect the skin, vancomycin injection to flush the wound. Postoperatively, by intravenous drip, a single dose of cefazoxime sodium at 2 g was used.Fig. 2 Postoperative pelvic digital radiography: a. sagittal plane b. crown plane.

Fig. 2

The patient developed recurrent fever after 1 days of surgery, and it was strange that if the machine was switched on, the patient developed a localized fever which then became generalized, and if the machine was switched off, no fever developed. The first fever was measured at a maximum temperature of 38.0 °C, and blood was immediately drawn for the patient, with a white blood cell count of 5.62 ∗ 109/L, a neutrophil percentage of 42.9 %, a lymphocyte percentage of 43.2 %, a calcitoninogen of 0.05, an ultrasensitive C-reactive protein of 8.71 mg/L, and a C-reactive protein of <10 mg/L. The second time the machine was turned on the patient again became febrile with a maximum temperature of 39.2 °C. White blood cell count 7.39 ∗ 109/L, neutrophil percentage 76.4 %, lymphocyte percentage 16.5 %, calcitonin 0.09, ultrasensitive C-reactive protein >10 mg/L, C-reactive protein 19.7 mg/L, the third time to turn on the machine and fever again measured a maximum body temperature of 39.2 °C, white blood cell count 7.83 ∗ 109/L, the neutrophil percentage of 24.7 %, the percentage of lymphocytes 24.7 %, lymphocyte percentage 57.1 %, calcitoninogen 0.12, ultrasensitive C-reactive protein >10 mg/L, C-reactive protein 20.9 mg/L, and several bacterial cultures during the period showed no bacterial growth (Table 1). Considering that the period of observing the effects coincided with the active spread of influenza virus, he was tested for influenza virus nucleic acid, and the results were negative. The patient did not develop rash, superficial lymph node enlargement, abdominal pain, dyspnoea or any other symptoms except fever, and his wounds remained clean and tidy.Table 1 Examination of the patient during fever.

Table 1	Body temperature (°C)	White cell count (109/L)	Neutrophil percentage (%)	Lymphocyte percentage (%)	Calcitonin	Ultrasensitive C-reactive protein (mg/L)	C-reactive protein (mg/L)	
First open	38	5.62	42.9	43.2	0.05	8.71	<10	
Second open	39.2	7.39	76.4	16.5	0.09	>10	19.7	
Third open	39.2	7.83	24.7	57.1	0.12	>10	20.7	

We removed his device after 14 days of observation due to the patient's development of fever associated with machine activation, which occurs when the machine is activated and improves on its own when the machine is switched off, and failure to find an effective way to control it. The patient's symptoms did not improve during this period. His symptoms of urinary and fecal dysfunction and lower limb hypokinesia remained unchanged in our subsequent follow up visits, and intermittent clean catheterisation was still being used to alleviate the symptoms, with no better solution found for the time being.

3 Discussion

SNM is a common treatment for neurogenic bladder, overactive bladder syndrome, neurogenic rectum, and other related conditions. SNM injection has FDA approval for use in OAB patients. In a study of 37 women after sacral nerve stimulator placement, the incidence of infection was 13.5% [2].In a prospective multicentre clinical study of 120 people with fecal incontinence, the most prevalent adverse events included implant site pain (28 %), paresthesia (15 %), altered sensation of irritation (12 %) and infection (10 %) [3]. Serious complications such as nerve injury are rare. A systematic review reported that nerve injuries associated with spinal cord stimulation (SCS) were mainly due to epidural haematoma or abscess caused by needle puncture, percutaneous lead placement, or during surgery for placement of paddle leads, haematoma or abscess. SNM have not reported complications related to neurological damage [4].In a 20-year review of the literature, Cameron estimated the risk of epidural haematoma to be 0.3 % and the risk of paralysis to be 0.03 %. Angela et al. reported a case of neurological sequelae due to post-SNS infection in a woman with severe fecal incontinence due to Crohn's disease who underwent SNS implantation and developed a wound infection, which required the device to be completely removed. A few days later, she developed leg pain and weakness. 6 months later, she developed persistent neurological deficits [5].

We present the case of a male patient with traumatic residual cauda equina injury and urinary and fecal dysfunction who developed fever associated with machine activation after undergoing stage I sacral nerve stimulator placement, manifested by a maximum axillary temperature of 39.2 °C. Repeated examinations did not observe any signs of infection and the patient developed fever only when activating the sacral nerve stimulator device. Cauda equina syndrome (CES) is a potentially devastating spinal condition associated with substantial morbidity, and often leads to litigation [6].The patient presented with bilateral pain around the buttocks and mild to moderate pain in the sacrococcygeal area during his stay in the rehabilitation unit, and was considered by the rehabilitation physician to have Complex Regional Pain Syndrome (CRPS). The exact underlying cause of the disease remains uncertain and various theories of pathogenesis have been proposed, including autonomic dysfunction, neurogenic inflammation, and altered neuroplasticity in the central nervous system [7]. Combined with the patient's history and symptoms, we can conclude that the patient has significant neurological damage.

Fever is a challenge for both clinicians and patients [8]. CNS circuits process heat afferent inputs from the skin and body core to control the activity of thermoeffectorial effectors that maintain body temperature across a variety of environmental and physiological challenges [9].In a systematic review of neurogenic fever after traumatic spinal cord injury, the prevalence of all-cause (known and unknown) fever after spinal cord injury ranged from 22.5 % to 71.7 %, with a mean incidence of 50.6 % and a median incidence of 50.0 %. The incidence of fever of unknown origin (neurogenic fever) ranged from 2.6 % to 27.8 %, with a mean incidence of 8.0 % and a median incidence of 4.7 %. Cervical and thoracic spine injuries were more frequently associated with fever than lumbar spine injuries. In addition, complete injuries have a higher incidence of fever than incomplete injuries. The pathogenesis of neurogenic fever after acute spinal cord injury is unclear [10]. Patients with neurogenic fever have higher body temperatures than those with non-neurogenic fever [11]. Temperature instability following brain injury likely involves hypothalamic injury, pathologic changes in cerebral blood flow, metabolic derangement, and a neurogenic inflammatory response.

The target nerve tissue for SNM is the third sacral nerve (S3). This nerve is part of the cauda equina and originates from the spinal cord cones that ends above L2. Human anatomical studies have shown that the axons of the sacral nerve are composed of both myelinated and unmyelinated ones. At lower spinal cord levels, such as S3, B fibres (preganglionic autonomic) are more dominant than A fibres, and smaller diameter A fibres, such as Aγ (sensory) and Aδ (pain, pressure, and stretch), are more dominant than larger diameter motor Aα fibres [12]. That is, the site of action of the SNM is a mixed nerve, and all of that site is theoretically affected when the device is switched on.

The patient did not develop a non-infectious fever after the injury, only after the SNM device was installed and activated, and the temperature returned to normal after it was switched off. We hypothesize that based on the patient's pre-existing nerve damage and disorders, the activation of the SNM somehow stimulated the relevant sites, causing the patient to develop a neurogenic fever. Unfortunately, for a variety of reasons, we were unable to specify what kind of nerve damage was present. However, it is still reasonable to speculate based on the available evidence, and it is reasonable to consider that the patient's fever was closely related to the sacral nerve stimulator placement, and we hope that this will contribute to the perioperative management of SNM in the future.

4 Conclusion

Non-infectious fever during SNM is a rare event. More case reports and investigations are needed in the future to identify the cause of the fever and its management.

Ethical approval

This case report doesn't require ethical approval based on the Chongqing Medical University ethics committee's guidelines. Ethical approval for this study was not required since we only reported 1 patient and we already got patient permission to perform the procedure. The patients/participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article. No animal studies are presented in this manuscript. No potentially identifiable human images or data is presented in this study.

Funding

The authors declare that this study received funding from the Senior Medical Talents Program of Chongqing for Young and Middle-aged Science supported by Chongqing Health Commission (2022GDRC014 ).

Author contribution

Jialei Zhao: Writing: review & editing, Formal analysis. Gang Chen: Resources, Contributed to revisions. All authors read and approved the final manuscript.

Guarantor

Gang Chen accepts full responsibility for the work and/or the conduct of the study, has access to the data, and controlled the decision to publish. Gang Chen becomes the guarantor for this work.

Research registration number

Does not need any registration.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

The original contributions presented in the study are included in the article/supplementary material; further inquiries can be directed to the corresponding author/s.
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