# Assessment of Upper Limb Nerves in Coronary Artery Disease Patients Undergoing Coronary Artery Bypass Graft

## TL;DR

This study examines how coronary artery bypass surgery affects upper limb nerves, finding changes in nerve function that may be due to surgical trauma.

## Contribution

The study introduces a novel approach to assess post-CABG neurological complications using pre- and post-surgery nerve conduction studies.

## Key findings

- Median nerve latency increased from 3.01 to 3.60 milliseconds post-surgery.
- Median nerve amplitude decreased from 16.49 to 12.30 microvolts after surgery.
- Ulnar nerve showed similar changes in latency, amplitude, and conduction velocity.

## Abstract

Background

Many patients experience pain in their upper limbs following surgical procedures involving median sternotomy, particularly those undergoing coronary artery bypass grafting (CABG). This type of pain, commonly reported by CABG patients, is often overlooked in hospital settings. Our study aims to address this issue by utilizing electrodiagnostic studies to understand this postoperative discomfort better.

Objectives

Cardiovascular procedures are standard and are trending toward endovascular interventions. Through this study, we aim to assess the occurrence of neurological issues in the upper limbs after CABG by comparing patients' preoperative and postoperative electrophysiological studies of the upper limb nerves.

Materials and methods

A prospective study was performed on 32 coronary artery disease (CAD) patients undergoing CABG to determine the effects of surgery on the upper limb nerves (median and ulnar nerves). We performed nerve conduction studies (NCS) and analyzed different parameters of both median and ulnar nerves pre and post-surgery.

Results

A change was noted in different NCS parameters of the median and ulnar nerves when we compared the pre and post-surgical values. The mean latency of the median nerve sensory increased from a minimum of 3.01 milliseconds at the preoperative level to a maximum of 3.60 milliseconds when assessed two weeks post-surgery. The mean amplitude decreased from 16.49 microvolts to a minimum of 12.30 microvolts when assessed two weeks post-surgery. The mean velocity decreased from 55.83 m/s at the preoperative value to a minimum of 45.03 m/s at the two weeks post-surgery assessment. The ulnar nerve also underwent similar changes.

Conclusion

The observed changes in latency, amplitude, and velocity might be attributed to various factors, including surgical trauma, inflammation, or alterations in the physiological state post-surgery. The sternotomy technique and the position and extent of opening the sternal retractor determine the prevalence of complications by causing injury to the medial and lateral cords of the brachial plexus after CABG. Careful preoperative and postoperative assessments of patients may aid in preventing, minimizing, and treating these often undiagnosed complications.