Iatrogenic nerve injuries: prevalence, diagnosis and treatment

Abstract

Background: Iatrogenic nerve injuries can result from direct surgical trauma, mechanical stress on a nerve due to faulty positioning during anesthesia, the injection of neurotoxic substances into a nerve, and other mechanisms. Treating physicians should know the risk factors and the procedure to be followed when an iatrogenic nerve injury arises.

Method: This review is based on pertinent articles retrieved by a selective search in PubMed and on the authors' own data from the years 1990-2012.

Results: In large-scale studies, 25% of sciatic nerve lesions that required treatment were iatrogenic, as were 60% of femoral nerve lesions and 94% of accessory nerve lesions. Osteosyntheses, osteotomies, arthrodeses, lymph node biopsies in the posterior triangle of the neck, carpal tunnel operations, and procedures on the wrist and knee were common settings for iatrogenic nerve injury. 340 patients underwent surgery for iatrogenic nerve injuries over a 23-year period in the District Hospital of Günzburg (Neurosurgical Department of the University of Ulm). In a study published by the authors in 2001, 17.4% of the traumatic nerve lesions treated were iatrogenic. 94% of iatrogenic nerve injuries occurred during surgical procedures.

Conclusion: A thorough knowledge of the anatomy of the vulnerable nerves and of variants in their course can lessen the risk of iatrogenic nerve injury. When such injuries arise, early diagnosis and planning of further management are the main determinants of outcome. If adequate nerve regeneration does not occur, surgical revision should optimally be performed 3 to 4 months after the injury, and 6 months afterward at the latest. On the other hand, if postoperative high resolution ultrasound reveals either complete transection of the nerve or a neuroma in continuity, surgery should be performed without any further delay. If the surgeon becomes aware of a nerve transection during the initial procedure, then either immediate end-to-end suturing or early secondary management after three weeks is indicated.

Figure 1

Algorithmic approach to iatrogenic peripheral nerve damage (modified from Antoniadis G, Pedro M, König R: Iatrogene Nervenläsionen-chirurgische Therapieoptionen. Neurologisch: Fachmagazin für Neurologie 2/13, 24-26)

Figure 2

The sciatic nerve was severed during total hip replacement for hip dysplasia 3 months previously. The nerve injury was not recognized and the patient was treated conservatively for several months. a) After MRI examination revealed that the nerve was completely separated, the patient was referred to our clinic. b) The operation revealed a completely severed sciatic nerve in the upper third of the thigh. c) After the neuroma was resected, d) nerve grafting using 12 sural nerve grafts from both calves was performed

Figure 3

The accessory nerve was damaged during a lymph node resection in the posterior triangle of the neck. a) The trapezius muscle remained paralyzed; surgical exploration revealed a completely severed nerve. b) An autologous sural nerve graft was used to bridge the defect.

Figure 4

The median nerve was damaged during an endoscopic carpal tunnel operation eight months previously in another hospital. A severed nerve was identified during exploratory surgery. a) Both nerve stumps were connected by a bridge of scar tissue. b) After resection of the neuroma, the median nerve was repaired with sural nerve grafts.