Another cause of surgical needle holder damage to surgical sutures

The Journal of Emergency Medicine, Vol 14, No 2, pp 201-204, 1996 Copyright 0 1996 Elsevier Science Inc. Printed in the USA. All rights reserved 0736-4679/96 $15.00 + .OO ELSEVIER

SSDI 0736-4679(95)02106-X

Selected Topics: Wound Care

ANOTHER Christine

C. Annunziata,

CAUSE

BA,*

OF SURGICAL TO SURGICAL

NEEDLE HOLDER SUTURES

DAMAGE

John G. Thacker, wm,t Julia A. Woods, BA,* and Richard F. Edlich, MD*

*Department of Plastic Surgery, University of Virginia School of Medicine, Charlottesville, Virginia tDepartment of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia Reprint Address: Richard F. Edlich, MD, PHD, Department of Plastic Surgery, Box 332, University of Virginia Medical Center, Charlottesville, VA 22908

0 Abstract-The sharp edges of the box lock of the needle holder can inadvertently damage the suture during instrument ties. Compression of a monofilament nylon suture between the sharp edges of the box lock of a surgical needle holder damages the suture, reducing its breaking strength. This adverse effect has been eliminated by one manufacturer whose needle holder box lock has rounded edges and sufficient space to permit passage of the suture. 0 Keywords-needle chamfer

the use of needle holder jaws with teeth to perform instrument ties. Instrument tying techniques are now constructed using only smooth needle holder jaws. Recent clinical experiences of some surgeons indicate that clamping sutures with some smooth needle holder jaws apparently damage the suture, thereby reducing its strength (2). Abidin et al. (2) confirmed that some smooth needle holder jaws tested by our laboratory did indeed damage sutures. This structural damage is due to the sharp outer edges of the smooth needle holder jaws whose edges have a 90-degree angular configuration. Mechanical filing of these sharp edges converts them into a smooth rounded configuration that does not damage sutures. Quality control measures have been devised that can be easily implemented by needle holder manufacturers, insuring that their smooth jaw surfaces are atraumatic to sutures. Emergency physicians have contacted our laboratory and indicated that the sharp edges of the box lock of the needle holder also can damage the suture and thereby reduce its breaking strength (Figure 1) . The box lock of the needle holder is the junction where the female member and the male member are secured forming the pivoting feature. A needle holder has been designed by one manufacturer (V. Mueller Division, Baxter Healthcare Corp., Deerfield, IL) whose box lock has rounded edges to prevent damage to sutures.

holder; nylon suture; box lock;

INTRODUCTION During the instrument tie technique, our group of investigators have demonstrated that the surgical needle holder can damage surgical sutures ( 1). Stamp et al. (1) first demonstrated that needle holder jaws with teeth produce distinct structural changes in monofilament sutures (5-0,6-O) that cause a marked reduction in their breaking strength. While needle holder jaws with teeth do not elicit injury to 6-O braided nylon sutures, they do cause a moderate degree of injury to 5-O braided nylon sutures. Clamping either monofilament or braided sutures by smooth needle holder jaws without teeth is atraumatic and does not alter the mechanical strength of sutures. These observations have caused emergency physicians and surgeons to abandon Wound Care is coordinated by Richard F. Edlich, ville, Virginia RECEIVED: ACCEPTED:

31 May 1995; FINAL 8 September 1995

SUBMISSION

RECEIVED:

MD, PhD,

of the University of Virginia Medical Center, Charlottes-

25 August 1995; 201

202

C. C. Annunziata et al.

Needle Holder

Female

Figure 1. Anatomy of a needle holder. edge of the ends of the box lock.

The chamfer

is the

The purpose of this report is to determine the effect of suture compression in the needle holder box lock or jaws on the mechanical strength of a surgical suture.

MATERIALS

The needle holders used in this study measured 12.5 cm in length and had smooth tungsten carbide jaw inserts. The jaws of these needle holders have rounded edges. The designs of the box locks of these needle holders are distinctly different. The box lock of the needle holder manufactured by V. Mueller Division is designed so that there is a space (Bevel Ease@) between the opposing ends of the box locks at the jaws and handles, allowing a suture to pass through easily (Figure 2). In addition, the chamfer of the needle holder has rounded edges. In contrast, the needle holder produced by Walter Lorenz, Inc. (Jacksonville, FL) has a box lock configuration whose opposing edges intimately contact each other when the needle holder jaws are closed, securely grasping a suture between these surfaces (Figure 2). In addition, the edges of the chamfer are sharp.

AND METHODS

Anatomy of a Needle Holder

Suture Breaking Strength

The needle holder is an instrument designed to hold a curved surgical needle (Figure 1). It consists of two first class levers (female member and male member) that rotate on a common fulcrum. The portions of the levers that grasp the needle are distal to the fulcrum and are called the jaws. The remaining portion of the lever, that portion which is held by the physician, is called the handle. On the end of the handle portion of each shank is a ringlet through which a finger tip can be placed. Once the jaws have gripped the needle, the physician can engage a locking mechanism to secure the needle in the needle holder jaws. The locking mechanism consists of individual ratchets with three engaging teeth that are attached to each handle next to the ringlets. Once the ratchets are engaged, the needle holder will grasp the needle without the physician applying further force to the ringlets because the handles are bent to engage the ratchets, thereby producing a spring force to disengage the ratchet. The box lock is the junction where the female member and the male member are secured, forming the pivoting feature. The box lock is located at the site of the fulcrum of the needle holder. Its surfaces are flat, allowing the lever arms to rotate. The chamfer is the edge of the ends of the box lock, being the end edge of the box lock at the jaw and the end edge of the box lock at the handle near the fulcrum. When the needle holder jaws are closed, there should be a space between the opposing chamfer edges so that a suture can slide through easily. In addition, the edges of the chamfer must be rounded to prevent injury to the suture.

The purpose of this study was to determine if compression of a suture by either the needle holder box lock or jaws could damage the suture. In the first part of the study, a 5-O monofilament nylon suture (Ethicon, Inc., Somerville, NJ) was positioned at the end of the needle holder box lock adjacent to its jaws (Figure 2).

Figure 2. Top, 12.5 cm needle holder with smooth jaws. Top insert: rounded edge box-lock has sufficknt SpaGs to pemnit passage of sutt&re. Bottom imrert: sharp edge box-lo& that compresses surgical suture.

203

Needle Holder Damage to Surgical Sutures

A force was then applied to the ringlets of each needle holder that was sufficient to engage the first opposing interlocking teeth of its ratchet mechanism for 15 seconds. This clamping of the suture in the needle holder box lock was repeated on 10 separate suture samples. The breaking strengths of the clamped sutures were measured by the tensile tester (Instron, Inc., Canton, MA) (1). In the next part of the study, the 5-O nylon suture was positioned at two separate sites between the faces of the smooth needle holder jaws. One site was positioned 2 mm from the ends of the needle holder jaws, while the other site was located 4 mm from the ends of the needle holder jaws. After positioning each suture, the first opposing teeth of the ratchet mechanism were interlocked for 15 seconds, compressing the suture between the needle holder jaws. This compression of the surgical suture was repeated using 10 separate suture samples for each site. Ten 5-O monofilament nylon sutures were not subjected to compression and served as the controls. The breaking strength of the suture samples were then measured. The breaking strength measurements are reported as the mean and standard deviation. The statistical analysis of the data was determined by the Student’s r-test.

I1 8.9 I

0

Control

.3

8.7 * .2

I r 2mm

4mm

Figure 4. When the sutures were positioned at diierent sites of the rounded edge smooth needle holder jaws, compression of the suture did not alter its breaking strength.

fected by closure of the box lock and exhibited a breaking strength comparable to that of the control sutures (Figure 3). In contrast, compression of the 5 -0 suture within the needle holder box lock produced by Walter Lorenz, Inc. significantly damaged the suture. The breaking strength of the sutures compressed within the box lock of the Walter Lorenz needle holder was 78% less than the breaking strength of the control sutures (p < .05).

RESULTS When the 5-O nylon suture was positioned adjacent to the rounded edges of the box lock manufactured by V. Mueller Division, the 5-O nylon suture was not af-

The rounded edges of both smooth needle holder jaws did not damage the sutures positioned 2 mm and 4 mm distal to the end of the needle holder jaws (Figure 4). The breaking strength of the compressed sutures between the needle holder jaws did not differ significantly from that of the control sutures.

DISCUSSION

Control

Straight Rounded Edge Edge Boxlock

Figure 3. After compression of the 5-O monofilament nylon sutures by the straight edges of the needle holder box lock, the breaking strength of the sutures was significantly less than that of the controls. Contact with the rounded edge of the box lock did not alter the breaking strength of the suture.

During the last decade, emergency physicians have frequently used continuous suture closure techniques for skin lacerations. This increased usage of continuous suture techniques has resulted from the availability of narrow diameter monofilament synthetic sutures that pass easily through tissue ( 3 ) . In addition, the obvious advantage of superior operative speed is another beneficial aspect of continuous closure technique over that of the interrupted suture techniques. However, there are certain recognized limitations of the continuous suture technique that should be recognized. A single defect in the continuous suture may lead to disruption of the entire continuous suture closure, whereas a comparable single defect in one inter-

C. C. Annunziata et al.

204

rupted suture loop will usually have no significant clinical impact. Although suture manufacturers exercise great care in manufacturing sutures with a uniform and reliable breaking strength, there is a possibility that physical damage to the suture can occur from the time the suture is removed from its package until it is manipulated and tied by the emergency physician. Such inadvertent damage to the suture may not be recognized before the wound is closed, only to result in disruption of the continuous suture and wound during the early postoperative period. A potential source of damage to the synthetic monofilament suture exists when the suture is clamped between the needle holder jaws during instrument tie techniques. The damaging effects of needle holder jaws with teeth have caused emergency physicians and surgeons to abandon their use during instrument tie techniques ( 1 ) . In addition, the manufacturers of needle holders are now producing smooth needle holder jaws with rounded edges that are not damaging to surgical sutures. This investigation presents another important cause of needle holder damage to surgical sutures. Surgical sutures may be inadvertently grasped by the box lock of the needle holder. Compression of the suture by the sharp edges of the box lock will dramatically reduce its breaking strength. This adverse effect of the needle holder can be corrected by the manufacturer by designing its rounded edge box lock to have sufficient space for passage of the suture.

CONCLUSION The purpose of this study was to determine if compression of the suture by either the box lock of the needle holder or the smooth needle holder jaws could damage the suture. The needle holders used in this study were 12.5cm-long needle holders with smooth tungsten carbide inserts with rounded edges. One needle holder had a box lock with sharp edges that compressed the suture. The other needle holder had a box lock with rounded edges and sufficient space to permit passage of the suture. Suture damage was measured by recording the breaking strength of 5-0 monofilament nylon sutures using a tensile tester. The needle holder whose box lock had straight edges that compressed the suture markedly reduced the suture breaking strength. In contrast, the rounded edge box lock of the needle holder that did not compress the suture did not alter suture breaking strength. In addition, clamping the suture between the rounded edges of the smooth needle holder jaws did not affect the suture breaking strength. On the basis of this study, it is recommended that emergency physicians use needle holders with box locks that have rounded edges and sufficient space to permit passage of the suture. research is supported by a grant from the Texaco Foundation, White Plains. The authors did not receive financial support from either the V. Mueller Division or Walter Lorenz Company.

Acknowledgment-This

REFERENCES 1. Stamp CV, McGregor W, Rodeheaver GT, Thacker JG, Towler MA, Edlich RF. Surgical needle damage to sutures. Am Surg. 1988; 54:300-6. 2. Abidin

MR,

Towler

MA,

Thacker

JG, Nochimson

GD,

McGregor W, Edlich RF. New atraumatic rounded-edge surgical needle holder jaws. Am J Surg. 1989; 157:241. 3. Pham S, Rodeheaver GT, Dang MC, Foresman PA, Hwang JC, Edlich RF. Ease of continuous dermal suture removal. 3 Emerg Med. 1990; 8:539-43.