Closure Tension Research Articles

Stretching Skin

The efficacy of intraoperative expansion in reducing the tension of wound closure was tested in young pigs. The young piglet as a model for studying human skin was characterized by finding a close similarity between the modulus of elasticity of young piglet skin and human abdominoplasty and mammaplasty skin (range 12.8 to 23.7 N/mm2 for piglet skin, 14.3 to 19 N/mm2 for human skin). The tension required to close a standardized wound was determined before undermining, after undermining, and finally after intraoperative expansion. These measurements were performed in 10 young pigs with an average weight of 11.5 kg. Undermining the wound edges resulted in a significant decrease in the force required to close the wounds (p less than 0.0001). Intraoperative expansion did not significantly decrease the tension. Previous work showing the importance of site and direction of pull on the tension for wound closure was confirmed in this study. Analysis of variance demonstrated that the tension required to close a standard wound is greater high on the pig's back than near the belly and near the shoulder as opposed to the hip for midflank wounds (p less than 0.0001). Increasing the extent of undermining from 62 to 136 cm2 significantly decreased the tension for wound closure (p less than 0.05). Further undermining did not result in a significant decrease in wound closure tension. In this model, intraoperative expansion offers no advantage over simple undermining. We suggest that the benefit reported by clinicians using intraoperative expansion may derive from an increase in the extent of undermining required to place expanders under the wound margins.

Re: V-Y Advancement Flaps for Tumor Excision Defects of the Eyelids

Resection of cutaneous malignancies of the medial canthus and lower lid create challenging wound closure problems. The V-Y flap closure technique achieves wound closure using adjacent tissue while minimizing closure tension. Twenty-three patients underwent resection of basal cell carcinomas in these two anatomical regions. In 22 patients a single V-Y flap was used to close the defect. In 1 patient two flaps were used. There were 2 patients with transient ectropion. No tissue loss or other complications occurred.

V-Y advancement flaps for tumor excision defects of the eyelids.

Resection of cutaneous malignancies of the medial canthus and lower lid create challenging wound closure problems. The V-Y flap closure technique achieves wound closure using adjacent tissue while minimizing closure tension. Twenty-three patients underwent resection of basal cell carcinomas in these two anatomical regions. In 22 patients a single V-Y flap was used to close the defect. In 1 patient two flaps were used. There were 2 patients with transient ectropion. No tissue loss or other complications occurred.

Chemosurgical Report: Indications for a Geometric Approach to Wound Closure following Mohs Surgery

Complex geometrically designed closures of defects following tumor removal by Mohs surgery are often utilized when simpler methods of direct tissue aposition would suffice. There are, however, specific advantages in certain instances of using a preplanned geometric closure. Utilization of the secondary defect created by movement of a rotation flap permits redirection of the forces of tension of wound closure. Preplanning of advancement flaps allows for selective placement of tissue dog ears and thereby allows for maximal camouflaging of excisional scars. The dynamics of these two flaps are discussed and specific examples illustrating the principles are reviewed.

The gluteus maximus musculocutaneous island flap: refinements in design and application.

The gluteus maximus island musculocutaneous flap has been described using a variety of designs. We employ an island whose long axis is directed toward the pressure sore, minimizing tension in wound closure. Skin overlying the greater trochanter is avoided. Previously undermined skin can be included in the flap. Fifty patients with ischial or sacral pressure sores have been managed by this technique. Superficial dehiscence occurred in 13 percent of patients, and deep dehiscence occurred in 10 percent. The dehiscence closed spontaneously in all but one patient. Forty-nine of the 50 patients experienced complete wound healing at the pressure sore site. The patients have been observed for an average of 20 months (range 3 to 38 months), with one recurrent pressure sore seen at 28 months postoperatively. The gluteus maximus musculocutaneous island flap has proven to be both reliable in healing and durable over the observed interval.

Experimental analysis of the adjunctive Z-plasty in the closure of fusiform defects.

Facial defects too large for primary closure can sometimes be repaired with the addition of a unilateral or bilateral adjunctive Z-plasty. In this study, the mechanics of the adjunctive Z-plasty are examined experimentally. In vivo experiments using piglets show that closure tension is decreased 30% by each Z-plasty. The true lengthening of the Z when transposed is 80% of that theoretically predicted. The deformation caused by fusiform excision and closure with and without undermining and with one or two Z-plasties is evaluated. In general, the Z-plasty exchanges deformation perpendicular to the long axis of excision for deformation parallel to that axis. A clinical case using the adjunctive Z-plasty for the repair of a large chin defect is reported.

Techniques in Eyelid Wound Closure

While one of the most basic techniques in eyelid surgery is the repair of an eyelid defect that involves the margin, many eyelid defects are still poorly repaired; and much confusion still exists in this area. Based upon sound anatomic and surgical principles, we suggest several modifications of classically described techniques: (1) The greyline suture is replaced by a tarsal suture through the meibomian gland orifices to provide a stronger closure and better alignment. (2) All tension of closure is supported by the deep tarsal sutures rather than by the margin sutures to avoid notch formation or unsightly scars. (3) A two-layered closure where orbicularis and tarsus is closed in a single layer is technically easier and gives results comparable to the classically taught three-layered closure. Conjunctival sutures in the tarsal portion of the eyelid are unnecessary and frequently cause corneal irritation. (4) When lid resection is performed, a pentagonal excision rather than a "V" or wedge resection should be used to minimize tension on the margin when closed. We present in an illustrated step-by-step fashion our preferred technique which gives consistently good results.

Pharmacology of the Esophageal Motor Function

In the striated muscle of the upper esophageal sphincter, tonic maintenance of closure is probably mediated via tonic central excitation of the extrinsic motor innervation; relaxation represents central inhibition of this mechanism. The motor nerves are probably cholinergic and act through nicotinic receptors like those of somatic striated muscle. In the striated muscle of the esophageal body, swallowing-induced contraction is also probably a cholinergic and nicotinic response. In the smooth muscle of the esophageal body, the control of contractions is cholinergic and muscarinic in part, but there is evidence for a nonadrenergic and noncholinergic component as well. The muscarinic component may arise from the cholinergic innervation of the longitudinal muscle layer. The other component may lie in the cryptic innervation of the circular muscular layer. In the smooth-muscled lower esophageal sphincter, resting closure tension appears to reflect a variety of possible control mechanisms. No single control system predominates. The evidence for muscarinic excitation is equivocal. An excitatory adrenergic alpha mechanism and inhibitory adrenergic beta receptors may contribute. A role for the polypeptide hormones from the gastrointestinal tract seems unlikely. Relaxation of the lower sphincter with swallowing seems not to involve any of these mechanisms, but is apparently accomplished by nonadrenergic noncholinergic inhibitory nerves like those present elsewhere in the gut (87). The possibility that the transmitter of these nerves is an adenine nucleotide has been raised from studies of other parts of the gut, but that hypothesis has not yet been examined critically in the lower esophageal sphincter.

Some Physiological Characteristics of the Esophagogastric Junction in the Opossum

Abstract Bilateral cervical vagotomy did not change closure tension or abolish relaxation with swallowing in the lower esophageal sphincter of the opossum, studied by manometry in vivo. Field electrical stimulation of serial transverse muscle strips, 2 mm wide, cut from a zone spanning the opossum esophagogastric junction, distinguished three regions. Muscle distal to the junction contracted during the stimulus. Muscle at the junction relaxed during the stimulus. Muscle proximal to the junction contracted after the stimulus. Transitional responses occurred. All responses were sensitive to tetrodotoxin. Muscle from the junction showed a steeper length-tension curve than muscle from adjacent regions. A steep length-tension curve was correlated in space with stimulus-induced relaxation. Basal tension during stretch to 150% of resting length was not sensitive to tetrodotoxin. A fraction of sphincter closure tension and relaxation with swallows are independent of central vagal connections. Muscle of the esophagogastric junction differs from that of adjacent regions in showing a steeper length-tension curve and nerve-mediated stimulus relaxation. These characteristics seem to define the sphincter. The sphincter in the opossum is less than 1 cm long.