Interstim For Bowel Control

Interstim therapy is highly recommended for patients with bowel and bladder urgency or frequency, who are not responsive or tolerant to anticholinergic therapy, have neurogenic disorders or the muscles at the perineal region are dysfunctional.
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Interstim For Bowel Control

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Interstim therapy is highly recommended for patients with bowel and bladder urgency or frequency, who are not responsive or tolerant to anticholinergic therapy, have neurogenic disorders or the muscles at the perineal region are dysfunctional.
It uses electrical stimulation from an impulse generator that sends the pulses to the sacral roots at the S3 foramen that are then transmitted to the brain which sends back signals to officiate bowel control. The nerve roots from the S3 foramen are shown to innervate the genital and anal sphincters. The temporary stimulation of this center results in perineal muscles contraction together with plantarflexion of the patient’s great toe.
This system modulates the sacral neural system to improve the signal transmission from the brain to muscles of bowel function to restore the function to as close as normal.

It uses electrical stimulation from an impulse generator that sends the pulses to the sacral
roots at the S3 foramen that are then transmitted to the brain which sends back signals to
officiate bowel control. The nerve roots from the S3 foramen are shown to innervate the
genital and anal sphincters. The temporary stimulation of this center results in perineal
muscles contraction together with plantarflexion of the patient’s great toe.

This system modulates the sacral neural system to improve the signal transmission from the brain to muscles of bowel function to restore the function to as close as normal.

Indications/why its done

Mainly indicated to help improve the patient’s quality of life because it is a safe, very effective and has good efficacy levels for long term purposes.

How is this procedure done?

The procedure is done in two stages;
  • test phase
  • the implantation or removal phase.
Before the procedure, patient evaluation is carried out to ensure that he is an appropriate candidate. The patient is counseled about the reasons he has to go through the procedure, its importance, and safety. Take the patient through the procedure; explain that it is simple and less invasive. Prophylactic antibiotics are administered before the procedure is carried out.
  • Test phase(office)
The test phase can be carried out in the office or theatre depending on patient apprehension to needles. In the office, the patient is made to lay prone without clothing including socks or stocking. The backside is sterilely readied for the procedure, draped to isolate the surgical site. Lidocaine with epinephrine, which is the most preferred local anesthetic, is given. A 20 G foramen needle is used to locate the S3 foramen with the help of fluoroscopy. It is inserted into the foramen and the depth of the foramen is determined. Temporary stimulation is applied to ascertain its position, the patient will perceive perineal muscle contraction and you will be able to see the big toe plantarflex. A unipolar lead is inserted through the needle after which the needle is carefully removed not to displace the lead. The lead is secured with sterile strips and dressing at the back and is attached to an external stimulator. The patient is put on antibiotics and is shown how to use the external stimulator for about 5-8 days before review. On review, >50% bowel movement improvement, the patient heads to implantation phase. <50% bowel movement improvement or if the test phase procedure failed, the procedure is redone in theatre..
  • Test phase ii (theatre)
In theatre, the patient is either put on a regional or general anesthesia. Long-acting muscle relaxants are however contraindicated as they impair the pelvic muscle motor response. Theatre procedure is indicated for the severely apprehensive patients and those patients whose office test phase failed or have a <50% bowel movement improvement. The preprocedure activities are similar to the office-based one. The foramen needle is inserted at the S3 foramen, a quadripolar lead is inserted through the needle and temporary stimulation is 56 | P a g e done at the four polar ends at positions 0,1,2,3 for response. The needle is carefully removed not to displace the lead. The lead is then tucked into the subcutaneous fat deep into the right buttock, the site where the pulse generator implant is to be implanted in the implantation phase. A temporary external stimulator is connected to the lead via an alternative exit site, different from the entry site to prevent superficial infection, if any, from spreading to the lead. Antibiotics are given for a period of two weeks prior review. On review, the lead is either removed or implantation of the permanent pulse implant generator is done.
  • Implantation phase
The implantation phase is done in theatre under general anesthesia. The length of the procedure is determined by the type of test phase that was carried out. It will take a shorter time if the test phase was done in theatre and longer if it was done as an office procedure. If it was an office procedure, the temporary external stimulator is removed, a quadripolar lead is inserted, tucked into the subcutaneous fat into the right buttock where the permanent pulse implant generator is inserted, the generator is tested before the closure of the incision.

Risks

  • Wound site infection which is a common occurrence.
  • Pain at the site which is due to infection or nerve impingement, lead migration or generator dysfunction.

Outcomes

Many reports show good recovery with the administration of antibiotics to minimize the chance of getting an infection. Good bowel movements have been recorded years after the procedure date; however, few failure rates have been registered. This, therefore, proves that Interstim therapy is a highly effective mode of treatment for chronic bowel or bladder disorders