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At least 19 recordsLinked to original sources
PubMed2001

Thoracic splanchnic nerves: implications for splanchnic denervation.

Splanchnic neurectomy is of value in the management of chronic abdominal pain. It is postulated that the inconsistent results of splanchnicectomies may be due to anatomical variations in the pattern of splanchnic nerves. The advent of minimally invasive and video-assisted surgery has rekindled interest in the frequency of variations of the splanchnic nerves. The aims of this study were to investigate the incidence, origin and pattern of the splanchnic nerves in order to establish a predictable pattern of splanchnic neural anatomy that may be of surgical relevance. Six adult and 14 fetal cadavers were dissected (n = 38). The origin of the splanchnic nerve was bilaterally asymmetrical in all cases. The greater splanchnic nerve (GSN) was always present, whereas the lesser splanchnic nerve (LSN) and least splanchnic nerve (ISN) were inconsistent (LSN, 35 of 38 sides (92%); LSN, 21 of 38 sides (55%). The splanchnic nerves were observed most frequently over the following ranges: GSN, T6-9: 28 of 38 sides (73%); LSN, when present, T10-11: (10 of 35 sides (29%); and ISN, T11-12: 3 of 21 sides (14%). The number of ganglionic roots of the GSN varied between 3 and 10 (widest T4-11; narrowest, T5-7). Intermediate splanchnic ganglia, when present, were observed only on the GSN main trunk with an incidence of 6 of 10 sides (60%) in the adult and 11 of 28 sides (39%) in the fetus. The higher incidence of the origin of GSN above T5 has clinical implications, given the widely discussed technique of undertaking splanchnicectomy from the T5 ganglion distally. This approach overlooks important nerve contributions and thereby may compromise clinical outcome. In the light of these variations, a reappraisal of current surgical techniques used in thoracoscopic splanchnicectomy is warranted.

Abdominal Pain↗
PubMed2006

Differentiated hemodynamic changes controlled by splanchnic nerve.

The splanchnic (SPL) nerve is a postganglionic sympathetic nerve involved in the tonic regulation of the cardiovascular system. Electrical stimulation of this nerve produces mesenteric vasoconstriction and it has been assumed that vasodilatory responses are dependent on inhibition of the vasoconstrictor tone. Several different central stimuli have been shown to dilate the hindquarter vascular bed and constrict the mesenteric vascular bed. To determine whether vasodilatory and vasoconstrictor effects in different vascular beds are elicited by activation of different sympathetic nerves, we investigated the hemodynamic changes in hindquarter, mesenteric and renal vascular beds evoked by electrical stimulation of the SPL nerve. Stimulation of the intact or sectioned SPL nerve in chloralose-anesthetized, artificially ventilated rats evoked increases in the hindquarter vascular conductance and simultaneously decreased the mesenteric and renal vascular conductance. Intravenous (i.v.) administration of L-NAME prior to stimulation of the proximal end of the sectioned SPL nerve abolished the increase in hindquarter conductance, suggesting the involvement of nitric oxide in this response. In assessing the hemodynamic effects of tonic activity on the SPL nerves, no significant changes were observed after unilateral section of the SPL nerve, but bilateral section of the SPL nerves decreased hindquarter conductance and did not significantly change the mesenteric conductance simultaneously. No consistent response was observed in the renal vascular bed after unilateral and subsequent contralateral section of the SPL nerves. These findings demonstrate that electrical stimulation of the SPL nerve produces mesenteric vasoconstriction and simultaneous hindquarter vasodilatation, which is mediated by nitric oxide. Moreover, the present data suggest that SPL nerves may provide a tonic vasodilatory tone in the hindquarter vascular bed and simultaneously a vasoconstrictor tone in another, undetermined vascular bed.

Analysis of Variance↗
PubMed2000

Unmyelinated nerve fibre analysis of the human lesser splanchnic nerve.

The aim of the present study is to analyse unmyelinated nerve fibres of the human lesser splanchnic nerve in relation to the ageing process. With the help of an image-analyser, we examined 30 human lesser splanchnic nerves. The analysis was conducted with the use of a new staining method that makes it possible to discriminate various structures of the nervous tissue. Our report provides for the first time information on the ageing process of the human lesser splanchnic nerve fibres. The results indicate that a decrease in transverse area and perimeter of unmyelinated axons is one of the important changes occurring in the human lesser splanchnic nerve during the ageing process.

Adult↗
PubMed1997

Myelinated nerve fibre analysis of the human small splanchnic nerve.

The aim of the present study is to analyse nerve fibres of the human small splanchnic nerve in relation to the ageing process. The analysis was conducted with the use of a new staining method that makes it possible to discriminate various structures of the nervous tissue. An image-analysing digitiser, a microscope with a drawing tube and a personal computer for storing data and performing statistical analyses were employed in this study. We examined 30 human small splanchnic nerves which were taken from cadaver specimens (20 males and 10 females) aged from 44 to 96 years. Our report may provide a first information concerning the ageing process of the human small splanchnic nerve. The results indicate that a decrease in transverse area and perimeter of myelinated axons in one of the important changes occurring in the human small splanchnic nerve with the ageing process.

Adult↗
PubMed1980

The effects of adrenergic antagonists on the serotonin levels of feline enterochromaffin cells after splanchnic nerve stimulation.

Cut splanchnic nerves were stimulated electrically at the preganglionic level in efferent direction in anesthetized cats with the adrenals ligated bilaterally. A significant decrease of the intracellular serotonin (5-HT) levels in populations (n = 20) of individual enterochromaffin cells (EC) in the mucosa from three different levels of the small intestine (distal duodenum, mid-jejunum and terminal ileum) was obtained. The intracellular 5-HT levels before and after stimulation were studied cytofluorimetrically in biopsies treated according to the Falck-Hillarp technique. One group of cats was pretreated with propranolol prior to stimulation. This prevented the decrease in fluorescence intensity effectively. Two other groups of cats were pretreated with phenoxybenzamine or phentolamine. These drugs also blocked the expected decrease in fluorescence intensity in 7 of 8 cats. In some biopsies there was an increased fluorescence intensity after nerve stimulation in cats given propranolol or phentolamine even though the drugs themselves had no intrinsic effects on the fluorescence intensity in control animals. It is concluded that efferent electrical stimulation of the splanchnic nerves can cause a release of 5-HT from gut EC by an adrenergic mechanism.

Animals↗
PubMed1999

Myelinated nerve fiber analysis of the human greater splanchnic nerve.

The purpose of the present study is to analyze the human greater splanchnic nerve in relation to aging. We adopted a new staining method which makes it possible to discriminate various structures of the nervous tissue. We examined 25 human greater splanchnic nerves from cadavers for anatomy dissection. We measured the number, area and perimeter of axons. The results reveal that: (1) there is no correlation between age and the number of axons; (2) the mean area and perimeter of axons increase with age, but not the total area and perimeter. We compared these results with those for the lesser splanchnic nerve. These morphological changes in the greater splanchnic nerve may indicate a kind of compensation through axon hypertrophy for hypofunctions in abdominal organ control.

Adult↗
PubMed1981

[Electrical responses recorded in the subdiaphragmatic branches of the vagus nerve upon stimulation of a splanchnic nerve].

Electrical responses of the vagus different branches to a single stimulus applied to the left major splanchnic nerve studied inq--chloralose--treated cats (70 mg/kg). Reflex responses in efferent fibers revealed different conduction velocities: 21.8; 4,5; 1.7 and 0.39 m/sec. The responses persisted after transection of both vagal cervical trunks, spinal cord at the 1st thoracic segment, and after i. v. administration of ganglioblocking agents hexonium or benzohexonium (1--2 mg/kg). The responses disappeared on increase in the stimulation rate to 20/sec and were facilitated after a preliminary series of stimuli. The data obtained suggest that the reflex arch is relayed on the cerebrospinal level and that at least three kinds of preganglionic sympathetic efferent fibers carry reflex firing.

Animals↗
PubMedDate not supplied

Adrenal vein catecholamines and neuropeptides during splanchnic nerve stimulation in cats.

Splanchnic nerve stimulation in bursts at low (5 Hz) and high (50 Hz) frequency (30 V, 1 msec; train duration 1 sec; train rate 0.5/second) was employed in 10 cats under halothane anesthesia, during 10-minute periods, while blood samples were concurrently collected from the adrenal vein and femoral artery for the measurement of norepinephrine (NE), epinephrine (EPI), dopamine (DA), Met-enkephalin (ME), neuropeptide Y (NPY), peptide YY (PYY) and neurotensin (NT). In Group I (n = 5), splanchnic nerve stimulation was initially applied at 5 Hz followed after 20 min by a 50 Hz stimulus, while in Group II (n = 5) the stimulation sequence was reversed. Adrenal vein and femoral artery plasma levels of catecholamines and neuropeptides were not significantly affected by the stimulation sequence, while a significant decrease in blood pressure response was observed in Group II during the 5 Hz stimulation as compared to Group I, indicating desensitization. Splanchnic nerve stimulation at 5 Hz caused a preferential increase in adrenal vein NE (9-fold) versus EPI (7-fold) levels as compared to baseline, while 50 Hz stimulation led to further comparable increases in NE (5-fold) and EPI (6-fold) levels. Significant increases in adrenal vein DA and neuropeptide levels were only observed during 50 Hz stimulation, with DA showing a 5-fold, ME a 2.6-fold and NPY a 3-fold increase as compared to 5 Hz stimulation, and NT a 3.6-fold increase as compared to baseline. Present findings indicate different dynamics in the movement of catecholamines and neuropeptides from the adrenal.

Adrenal Glands↗
PubMed1997

[Computerized tomography-guided neurolytic block of the splanchnic nerve].

CT-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. CT yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholization, 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and died 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celiac anatomy and complicate the percutaneous block of the celiac plexus.

Abdominal Neoplasms↗
PubMed2005

Percutaneous splanchnic nerve radiofrequency ablation for chronic abdominal pain.

BACKGROUND: Splanchnic nerve block is a useful alternative to coeliac plexus block in the management of patients with chronic upper abdominal pain. The predictable relationship of the splanchnic nerves to other structures allows for accurate needle placement and hence a low risk of iatrogenic damage. Radiofrequency ablation (RFA) uses a high frequency alternating current to heat tissues leading to thermal coagulation. It produces predictable and accurate lesions and hence is useful alternative to more conventional phenol and alcohol neurolytic methods. METHODS: The present study examined a series of 10 patients undergoing percutaneous RFA splanchnic nerve blockade for chronic pancreatitis. Pain levels, anxiety, quality of life, daily activity, mood and interpersonal relationships were all assessed pre- and postprocedure, using a visual analogue score. Median follow-up was 18 months (range: 12-24 months). Statistical analysis was undertaken using non-parametric Wilcoxon matched pair analysis, statistical significance was set at the 95% confidence intervals. RESULTS: Splanchnic nerve RFA not only led to a decrease in pain scores, opiate analgesia use and acute admissions for pain; but it also resulted in improvement of other parameters associated with long-term debilitating chronic pain, such as anxiety levels, daily activity, overall mood and general perception of health. There were no major complications. All changes observed were statistically significant. CONCLUSION: Although preliminary data regarding RFA ablation of splanchnic nerves are encouraging, further trials are also needed comparing percutaneous splanchnic nerve ablation with opioid analgesia and coeliac plexus blockade.

Abdominal Pain↗
PubMed1982

Greater splanchnic nerve activity in the rat.

The greater splanchnic nerve trunks in the rat, unlike in other experimental animals, do not join celiac plexus directly. These nerve trunks join small ganglia, the cardiac ganglia, on either side. The cardiac ganglia are located about 1 cm rostro-lateral to unpaired celiac ganglion. The greater splanchnic nerve activity immediately proximal to celiac ganglion is predominantly post-ganglionic in the rat. On the other hand, the activity of the greater splanchnic nerve proximal to the celiac ganglion is predominantly preganglionic in other experimental animals, (e.g., cat), In the rat, preganglionic sympathetic nerve activity is predominant in the segment of the greater splanchnic nerve proximal to the cardiac ganglion.

Animals↗
PubMed1993

Regulation of the bladder neck closure by lumbar splanchnic nerves at ejaculation in the dog.

To clarify the role of canine thoracolumbar splanchnic nerves for bladder neck closure during ejaculation, these nerves of adult male mongrel dogs were exposed under anesthesia using ketamine hydrochloride and pentobarbital, and electrical stimulation and anatomical dissection studies were performed. Bladder neck closure by the stimulation of each sympathetic nerve was monitored with a 10 Fr silicon catheter equipped with pressure-sensitive rubber balloon placed at the bladder neck. The dissection study revealed that canine thoracolumbar splanchnic nerves consisted of two nerve groups: one branching from the sympathetic trunks at thoracic and L1 ganglia, reaching caudal mesenteric plexus (CMP) through the anterior wall of the aorta, the other branching from the sympathetic trunks at level L2-L5 ganglia, reaching CMP through the posterior side of the bilateral spermatic arteries. The former were designated intermesenteric splanchnic nerves, the latter lumbar splanchnic nerves. No bladder neck closure was observed by electrical stimulation of the distal end of severed intermesenteric splanchnic nerves or of the sympathetic trunks at the lumbopelvic level among 10 dogs examined. At least one lumbar splanchnic nerve generated the closure in all 10 dogs and generally, a few lumbar splanchnic nerves, generated the closure. The results indicate that bladder neck closure during ejaculation is generated by lumbar splanchnic nerves regardless of their branching levels from lumbar sympathetic ganglia, but not by either intermesenteric splanchnic nerves or pelvic sympathetic trunks.

Animals↗