Acute & Chronic Anal Pain
Dr Cristaldi explains acute and chronic anal pain
How do we assess and treat anal pain?
Before proceeding to any treatment in patient with acute and chronic anal pain is crucial to achieve the correct diagnosis and understand the true underlying reason which is responsible for this condition. How to reestablish the right diagnosis? The first step is obtaining complete past medical and surgical history and to establish what are the trigger and predisposing factors that may have initiated the pain cycle. Some of the most important factors are
- Acute constipation with excessive straining during defecation
- History of chronic constipation with repeated excessive straining
- History of single or multiples anal surgeries
- History of single level multiple vaginal deliveries
- History of pelvic or sacral trauma
It is also extremely important to objectively assess impact and the relevance that pain and associated symptoms may have on the patient quality of life. For this purpose, we request the patient during or before the consultation to fill validated questionnaires which may help us to understand the patients specific circumstances.
Physical examination including internal and the sternal assessment of the anal area is performed as initial step to understand and rule out the presence of any associated conditions that may be responsible for the patient’s symptoms. External examination would also include sensory blunt stimulations (Q-tip test) of the perianal and perineal area to map the pain territory distribution. Internal examination is performed whenever possible to establish is the compression of specific anatomical area triggers the onset of pain.
Further step is to perform certain diagnostic tests which may varies according to specific symptoms and clinical presentations. Those tests are
- Anorectal manometry which assess pressure profiles of the anal sphincter muscles during rest and during the most common working activities such as squeezing and straining. This test is always associated to sensory and compliance tests of the rectum and anal canal that are utilized to understand if the dynamic of rectal emptying occurs normally or there are instead certain dysfunctions which plays a significant role in the onset of anal pain.
- Anorectal superficial electromyography which assess sphincter muscle activity during resting and working phases and simultaneously recording the activity of certain accessory muscles which may interfere negatively during certain physiological functions such as bowel motion. This test is also very important to understand the control and command that the patient has on anal and pelvic muscle.
- Needle electromyography. This test is occasionally performed by our Consultant neurologist to assess if certain conditions such as post-traumatic denervation or paradoxical contraction of certain anal/pelvic muscle which may predispose to certain specific dysfunctions that interfere with normal rectal emptying during defecation leading to chronic excessive straining and ultimately to regional pain
- Pudendal Nerve Latency Test
How do we treat anal pain?
Depending of the final diagnosis certain specific treatment are available to relieve the patient from pain and the most common are
- Pudendal Nerve anesthetic block under neurophysiological guidance is an office procedure done under local anesthesia where a special needle connected to a special neuro-stimulating device allows the precise localization of the pudendal nerve followed by the injection of local anesthetic agent that blocks the sensitive component of the nerve and therefore relief pain. This block as it temporary is also called test block but the duration and effect may be variable and in some patient its effect may be long-lasting. In the vast majority of patients, the effect only last for few days and then returns the usual levels. Despite that, a successful test block even for just few hours is a strong predictor of success another procedure we use to block the nerve for a longer period called Pulsed Radiofrequency.
- Pulsed radiofrequency is similar to the previous procedure as pudendal nerve is always reached via percutaneous injection under local anesthesia using the same neuro-stimulating device. When the nerve is reached a controlled thermal energy delivered by pulsed radiofrequency is applied to the nerve achieving a gentle heating the nerve, which can reduce the pain signals and help control chronic pain. The effect is long lasting usually from 4 to 24 months.
- Medical treatment is also utilized in addition or as substitute of nerve block in case of milder symptoms or contraindication to the above described procedure. Different medication effective on chronic pain may be used according to the doctor indications