Computed Tomography-Guided Percutaneous Radiofrequency Ablation of the Splanchnic Nerves as a Single Treatment for Pain Reduction in Patients with Pancreatic Cancer

The aim of this paper is to prospectively evaluate the efficacy and safety of percutaneous computed tomography (CT)-guided radiofrequency (RF) neurolysis of splanchnic nerves as a single treatment for pain reduction in patients with pancreatic cancer. Patients with pancreatic ductal adenocarcinoma suffering from abdominal pain refractory to conservative medication who underwent CT-guided neurolysis of splanchnic nerves by means of continuous radiofrequency were prospectively evaluated for pain and analgesics reduction as well as for survival. In all patients, percutaneous neurolysis was performed with a bilateral retrocrural paravertebral approach at T12 level using a 20 Gauge RF blunt curved cannula with a 1cm active tip electrode. Self-reported pain scores were assessed before and at the last follow-up using a pain inventory with numeric visual scale (NVS) units. The mean patient age was 65.4 ± 10.8 years (male-female: 19-11). The mean pain score prior to RF neurolysis of splanchnic nerves was 9.0 NVS units; this score was reduced to 2.9, 3.1, 3.6, 3.8, and 3.9 NVS units at 1 week, 1, 3, 6, and 12 months respectively (p < 0.001). Significantly reduced analgesic usage was reported in 28/30 patients. Two grade I complications were reported according to the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system. According to the results of the present study, solely performed computed tomography-guided radiofrequency neurolysis of splanchnic nerves can be considered a safe and efficacious single-session technique for pain palliation in patients with pancreatic ductal adenocarcinoma suffering from abdominal pain refractory to conservative medication. Although effective in pain reduction the technique seems to have no effect upon survival improvement.

Recording of Electrically Evoked Neural Activity and Bladder Pressure Responses in Awake Rats Chronically Implanted With a Pelvic Nerve Array

Bioelectronic medical devices are well established and widely used in the treatment of urological dysfunction. Approved targets include the sacral S3 spinal root and posterior tibial nerve, but an alternate target is the group of pelvic splanchnic nerves, as these contain sacral visceral sensory and autonomic motor pathways that coordinate storage and voiding functions of the bladder. Here, we developed a device suitable for long-term use in an awake rat model to study electrical neuromodulation of the pelvic nerve (homolog of the human pelvic splanchnic nerves). In male Sprague-Dawley rats, custom planar four-electrode arrays were implanted over the distal end of the pelvic nerve, close to the major pelvic ganglion. Electrically evoked compound action potentials (ECAPs) were reliably detected under anesthesia and in chronically implanted, awake rats up to 8 weeks post-surgery. ECAP waveforms showed three peaks, with latencies that suggested electrical stimulation activated several subpopulations of myelinated A-fiber and unmyelinated C-fiber axons. Chronic implantation of the array did not impact on voiding evoked in awake rats by continuous cystometry, where void parameters were comparable to those published in naïve rats. Electrical stimulation with chronically implanted arrays also induced two classes of bladder pressure responses detected by continuous flow cystometry in awake rats: voiding contractions and non-voiding contractions. No evidence of tissue pathology produced by chronically implanted arrays was detected by immunohistochemical visualization of markers for neuronal injury or noxious spinal cord activation. These results demonstrate a rat pelvic nerve electrode array that can be used for preclinical development of closed loop neuromodulation devices targeting the pelvic nerve as a therapy for neuro-urological dysfunction.

Sympathetic nerves control bacterial clearance

A neural reflex mediated by the splanchnic sympathetic nerves regulates systemic inflammation in negative feedback fashion, but its consequences for host responses to live infection are unknown. To test this, conscious instrumented sheep were infected intravenously with live E. coli bacteria and followed for 48 h. A month previously, animals had undergone either bilateral splanchnic nerve section or a sham operation. As established for rodents, sheep with cut splanchnic nerves mounted a stronger systemic inflammatory response: higher blood levels of tumor necrosis factor alpha and interleukin-6 but lower levels of the anti-inflammatory cytokine interleukin-10, compared with sham-operated animals. Sequential blood cultures revealed that most sham-operated sheep maintained high circulating levels of live E. coli throughout the 48-h study period, while all sheep without splanchnic nerves rapidly cleared their bacteraemia and recovered clinically. The sympathetic inflammatory reflex evidently has a profound influence on the clearance of systemic bacterial infection.

Nerve-sparing radical hysterectomy: steps to standardize surgical technique

AimThe primary objective of this review was to study and analyze techniques of nerve-sparing radical hysterectomy so as to be able to characterize and elucidate intricate steps for the dissection of each component of the pelvic autonomic nerve plexuses during nerve-sparing radical hysterectomy.MethodsThis review was based on a five-step study design that included searching for relevant publications, selecting publications by applying inclusion and exclusion criteria, quality assessment of the identified studies, data extraction, and data synthesis.ResultsThere are numerous differences in the published literature concerning nerve-sparing radical hysterectomy including variations in techniques and surgical approaches. Techniques that claim to be nerve-sparing by staying above the dissection level of the hypogastric nerves do not highlight the pelvic splanchnic nerve, do not take into account the intra-operative patient position, nor the fact that the bladder branches leave the inferior hypogastric plexus in a ventrocranial direction, and the fact that inferior hypogastric plexus will be drawn cranially with the vaginal walls (if this is not recognized and isolated earlier) above the level of hypogastric nerves by drawing the uterus cranially during the operation.ConclusionsThe optimal nerve-sparing radical hysterectomy technique has to be radical (type C1) and must describe surgical steps to highlight all three components of the pelvic autonomic nervous system (hypogastric nerves, pelvic splanchnic nerves, and the bladder branches of the inferior hypogastric plexus). Recognizing the pelvic splanchnic nerves in the caudal parametrium and the isolation of the bladder branches of the inferior hypogastic plexus requires meticulous preparation of the caudal part of the ventral parametrium.

Anti-inflammatory reflex action of splanchnic sympathetic nerves is distributed across abdominal organs

The splanchnic anti-inflammatory pathway has been proposed as the efferent arm of the inflammatory reflex. Although much evidence points to the spleen as the principal target organ where sympathetic nerves inhibit immune function, a systematic study to locate the target organ(s) of the splanchnic anti-inflammatory pathway has not yet been made. In anesthetized rats made endotoxemic with lipopolysaccharide (LPS, 60 µg/kg iv), plasma levels of tumor necrosis factor-α (TNF-α) were measured in animals with cut (SplancX) or sham-cut (Sham) splanchnic nerves. We confirm here that disengagement of the splanchnic anti-inflammatory pathway in SplancX rats (17.01 ± 0.95 ng/ml, mean ± SE) strongly enhances LPS-induced plasma TNF-α levels compared with Sham rats (3.76 ± 0.95 ng/ml). In paired experiments, the responses of SplancX and Sham animals were compared after the single or combined removal of organs innervated by the splanchnic nerves. Removal of target organ(s) where the splanchnic nerves inhibit systemic inflammation should abolish any difference in LPS-induced plasma TNF-α levels between Sham and SplancX rats. Any secondary effects of extirpating organs should apply to both groups. Surprisingly, removal of the spleen and/or the adrenal glands did not prevent the reflex splanchnic anti-inflammatory action nor did the following removals: spleen + adrenals + intestine; spleen + intestine + stomach and pancreas; or spleen + intestine + stomach and pancreas + liver. Only when spleen, adrenals, intestine, stomach, pancreas, and liver were all removed did the difference between SplancX and Sham animals disappear. We conclude that the reflex anti-inflammatory action of the splanchnic nerves is distributed widely across abdominal organs.