ABSTRACT
In visceral pelvic pain secondary to (radical) hysterectomy or excisional surgery of the parametria, the pain occurred from lesions of the IHP, which can be considered as “pelvic phantom pain” and may be due to the development of neuromas of the IHP comparable with phantom stump pain following lower extremity amputation. However, in order to try to surgically find pelvic neuromas in the IHP even by laparoscopy is utopic; destruction of this plexus is not an option as it is involved in the important pelvic visceral reflexes (16), and blockade of all afferent pathways is also very difficult as there are five major autonomic pathways that can transmit nociceptive information (17). Information may also not necessarily follow just one pathway, and high stimuli may result in the activation of neighboring unmyelinated fibers originating from a different site so that a blockade of just one particular pathway is most unlikely to provide complete pain relief. Thus, the aim of the blockade is to try to block the most possible amount of pathways involved in pain transmission. As the IHP is composed of three different functional levels as we have previously demonstrated (7), the kind of injured afferent sympathetic fibers and consequently the site of the blockade of afferent pathways could depend on the level of the lesion on the plexus: in lesions of the first segment (upper third)—as in simple hysterectomy-the injury will affect the majority of the afferent fibers passing through both inferior hypogastric nerves and thereafter the SHP. In lesions affecting the second segment of the IHP, injuries of the sympathetic fibers contained in the first segment will be associated with lesions of the sympathetic fibers joining the sympathetic trunks, so that pain is generally associated with a sensation of fullness of the rectum or the bladder. A lesion of the lower third of the IHP, as in a radical hysterectomy or deep anterior rectum resection, will affect the pelvic splanchnic nerves. These nerves are branches from the anterior rami of the sacral nerve roots S2, S3, and S4/5 and contain the pelvic parasympathetic nerves so that their bilateral destruction induces systematic atonia of the bladder and of the rectum (18,19). Thus, in patients with suspected elective lesions of the first and/or the second segments of the plexus as in a simple hysterectomy, plastic or resection of the sacrouterine ligaments, we electively blocked the SHP: different surgical (20) and chemical (21) blockades of the SHP have been reported in literature, but all these techniques are destructive and irreversible. We opted for a more expensive but reversible and nondestructive method, the LION procedure for neuromodulation to the SHP. This laparoscopic technique does not require extensive dissection, and the entire plexus can be covered with just one multiple-channel electrode.
