Lesser Splanchnic Nerve

nervus splanchnicus minor

The lesser splanchnic nerve is formed by preganglionic sympathetic fibres from the 10th and 11th thoracic ganglia (T10-T11). It descends with the greater splanchnic nerve on the anterolateral vertebral surface, passes through the diaphragmatic crus, and synapses primarily in the aorticorenal ganglion, with some fibres reaching the superior mesenteric ganglion. It supplies sympathetic innervation to the kidney, the proximal ureter, and parts of the midgut, and conveys visceral afferent pain signals from these organs.

Region: Chest

Clinical Relevance

Clinical Notes

The lesser splanchnic nerve carries the visceral pain afferents from the kidney and upper ureter, which is why ureteral colic from upper ureteric calculi produces flank pain radiating to the groin. Splanchnic nerve neurolysis targeting both greater and lesser splanchnic nerves provides broader upper abdominal pain relief than greater splanchnic neurolysis alone. Thoracoscopic splanchnicectomy has been used for chronic pancreatitis pain with variable outcomes.

Pathology

Common Injuries & Conditions

Renal Colic Pain Pathway

Visceral pain afferents from the kidney and proximal ureter travelling in the lesser splanchnic nerve to T10-T11 explain why ureteral colic from upper ureteral calculi produces severe flank pain radiating anteriorly to the groin, managed acutely with NSAIDs, opioids, and alpha-blockers to facilitate stone passage.