Keep your cool to reduce post haemorrhoidectomy pain

Abstract

Haemorrhoids are anal cushions which play a crucial role in normal rectal emptying and continence.¹ Haemorrhoidal disease develops due to deterioration of the supporting collagen and fibroelastic tissue of these anal cushions which leads to abnormal downward displacement and vascular dilatation. Symptomatic haemorrhoids affect millions world-wide and are considered one of the most common medical conditions in the general population.^{2, 3}

Third and fourth degree haemorrhoids are effectively treated with open haemorrhoidectomy, which is not an appealing proposition to many patients due to the inevitability of post-operative pain. Continual refreshment of literature provides evidence-based recommendations for pain management to guide surgeons and anaesthetists. Intraoperatively, pain reduction strategies include the use of pudendal nerve blocks, and cautery rather than suture ligation of the vascular pedicle. Open Haemorrhoidectomy with (more expensive) devices such as Ligasure or Harmonic scalpel have an evidence-base which supports shorter operative time, lower blood-loss, less post-operative pain and similar long term results compared to conventional electrocautery.^4-6 Post-operative pain management strategies include laxatives, oral metronidazole and topical glyceryl trinitrate.⁷

One must wonder why device choice would contribute to post-operative pain level. A sensible possibility is the role of unintended adjacent thermal tissue damage. Conventional diathermy utilizes electrical energy through the tissue to generate heat that causes protein denaturation and tissue desiccation. Ligasure uses bipolar radiofrequency energy to achieve precise tissue coagulation, by continuously monitoring tissue impedance and delivering controlled energy, causing collagen and elastin fibres to denature and fuse. The Harmonic scalpel uses ultrasonic vibrations at 55500 Hz to cut and coagulate tissue simultaneously by converting electrical energy into mechanical vibrations, which cause protein denaturation in tissues.⁸ A study which utilized light microscopy and morphometric imaging analysis nicely compared lateral thermal damage to the peritoneum between monopolar diathermy, Ligasure and Harmonic scalpel. Mean lateral thermal damage values were 216, 144, and 90 μm respectively, suggesting that Ligasure and Harmonic cause roughly half as much potential damage to surrounding tissue compared to diathermy.⁹

If a surgeon's gloved finger is placed underneath thin tissue during open abdominal surgery to guide the diathermy, it is quickly withdrawn after a few seconds when the heat elicits enough pain. A patient's highly sensitive anorectal mucosa and sphincters during haemorrhoidectomy do not have this luxury to withdrawn, and therefore must suffer inadvertent ‘superficial burn’ trauma, which is likely to play some role in post-operative pain. Superficial burns require up to 10 days to heal, the usual time it takes for post haemorrhoidectomy pain to largely subside.¹⁰ Thus, a simple manoeuvre to reduce this pain (regardless of which device is used) is intermittent cooling of anal tissue with a few millilitres of saline flush throughout the surgical procedure, analogous to ‘first aid’ to prevent thermal injury. This is cheap, does not affect operative time and has no conceivable risks. Anecdotally patients report less pain post operatively and thus seems effective. Further benefits would be reduced post-operative opioid use and earlier return to function for patients.

Tissue cooling during haemorrhoidectomy is a rational, low-risk high-reward proposition, yet is not widespread and has never been evaluated in the literature as a means to reduce post-operative pain. It provides a simple avenue for surgeons to trial in their own practice. Of course, it requires cohort studies or randomized controlled trials to provide higher quality evidence rather than anecdotal suggestion.

Mina Sarofim: Conceptualization; investigation; writing – review and editing.