Chapter 22 Epineurial Suture, Split, and Graft Repair
Epineurial Suture
End-to-End Repair
• When a nerve has been transected or has a focal lesion in continuity and trimming of the proximal and distal neuroma does not result in a sizable gap, end-to-end repair without a lot of tension can sometimes be accomplished (Figure 22-1).
• After resection to healthy tissue, the gap is small enough to be closed by drawing the resultant trimmed stumps together. An epineurial end-to-end repair is the standard nerve repair.
• The important step, once repair is deemed necessary, is to trim both nerve ends to healthy fascicular structure (Figure 22-2, left). Some form of magnification aids in determining a healthy fascicular pattern (see Figure 22-2, right).
• If there is significant hemorrhage from either stump, the stump is gently grasped between the surgeon’s thumb and index finger, and saline is dripped on the stump. If patience is not rewarded, the offending vessel should be accurately cauterized with a fine bipolar forceps.
• Once this is done, it is time to suture the stumps together. On occasion, the longitudinal epineurial vessels on either stump can be used as a guide to help align the stumps. We prefer to pass the needle through the lateral epineurium. This is done at a similar site on the opposite stump and repeated on the opposite side of the nerve at 180 degrees.
• These sutures are then tied, usually simultaneously, by the surgeon and surgeon’s assistant (Figure 22-3).
• Suture line tension is minimized by mobilizing the proximal and distal stumps. In some circumstances (e.g., splitting off the origin of musculocutaneous nerve from the lateral cord), considerable relaxation is achieved. In other circumstances (e.g., ulnar and radial nerves), transposition will shorten the gap. In other sites (e.g., midarm median nerve), little can be gained.
• We use only slight joint flexion to shorten the interval between stumps. If significant joint flexion is required, we utilize grafts instead.
• After the lateral sutures are tied, sutures are placed halfway between each lateral suture and then between that suture and the lateral one and so forth until an anterior row of sutures is placed (Figure 22-4).
• The lateral sutures are reversed to invert the nerve so that the backside is exposed. This is then sutured in the same way as the anterior side of the nerve.
• We then like to roll the repair site between a moistened forefinger and thumb to straighten out the fascicular structure and align the two stumps as well as possible.
• When proximal and distal nerve stumps are of different sizes, it is especially important to use the preceding technique so that the stumps are well apposed.
• Visualization of fascicular architecture may be of value so that previously connected fascicles can be realigned fairly accurately. This can sometimes be done even though the repair is at an epineurial rather than a fascicular level.
Perineurial Suture
• A discussion of end-to-end repair raises the question of individual versus group fascicular repair. We occasionally do fascicular end-to-end repair in a split repair, when grafts are not necessary (seldom the case), but not when the whole cross section of the nerve needs repair. Much depends on the fascicular structure of the damaged nerve. If there are only a few fascicles, they should be matched as closely as is possible. If a group of fascicles are solely motor or sensory, and those groups can be reasonably defined in both proximal and distal stumps, those particular proximal and distal elements should be apposed.
