Progressive Tightening of Pulley Sutures for Primary Repair of Large Scalp Wounds

Management of Scalp Injuries

Soft tissue wounds in the scalp are a common occurrence after trauma or resection of a malignancy. The reconstructive surgeon should strive to use the simplest reconstructive technique while optimizing aesthetic outcomes. In general, large defects with infection, previous irradiation (or require postoperative radiation), or with calvarial defects usually require reconstruction with vascularized tissue (ie, microvascular free tissue transfer). Smaller defects greater than 3 cm that are not amenable to primary closure can be treated with local flap reconstruction. In all cases, the reconstruction method will need be tailored to the patient's health status, desires, and aesthetic considerations.

Scalp and Forehead Injury: Management of Acute and Secondary Defects

The primary challenges in scalp reconstruction are the relative inelasticity of native scalp tissue and the convex shape of the calvarium. All rungs of the reconstructive ladder can be applied to scalp reconstruction, albeit in a nuanced fashion due to the unique anatomy and vascular supply to the scalp. Important defect variables to incorporate into the reconstructive decision include site, potential hairline distortion, size, depth, concomitant infection, prior radiation therapy, planned adjuvant therapy, medical comorbidities, patient desires, and potential calvarium and dura defects.

Synergistic Effect of Chitosan and Selenium Nanoparticles on Biodegradation and Antibacterial Properties of Collagenous Scaffolds Designed for Infected Burn Wounds

A highly porous scaffold is a desirable outcome in the field of tissue engineering. The porous structure mediates water-retaining properties that ensure good nutrient transportation as well as creates a suitable environment for cells. In this study, porous antibacterial collagenous scaffolds containing chitosan and selenium nanoparticles (SeNPs) as antibacterial agents were studied. The addition of antibacterial agents increased the application potential of the material for infected and chronic wounds. The morphology, swelling, biodegradation, and antibacterial activity of collagen-based scaffolds were characterized systematically to investigate the overall impact of the antibacterial additives. The additives visibly influenced the morphology, water‑retaining properties as well as the stability of the materials in the presence of collagenase enzymes. Even at concentrations as low as 5 ppm of SeNPs, modified polymeric scaffolds showed considerable inhibition activity towards Gram-positive bacterial strains such as Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in a dose-dependent manner.

Measuring Forces in Suture Techniques for Wound Closure

BACKGROUND

The use of sutures remains the first choice for wound closure. However, incorrect use of a suture technique can lead to impaired healing. Many techniques are described for high-tension wounds, but not much is known about their mechanical properties. Complications of excessive tension include dehiscence, infection, and ischemic necrosis and could be prevented. This study aimed to compare forces in five techniques (single, horizontal mattress, vertical mattress, pulley, and modified pulley suture) in a standardized wound tension model.

MATERIALS AND METHODS

A standardized neoprene wound model was developed on the ForceTRAP system (MediShield B.V., Delft, The Netherlands) to mimic a 5 Newton (N) wound. Five different suture techniques were each repeated 10 times by a student, resident dermatology, and dermsurgeon. The pulling force of the suture's first throw was measured with the Hook-in-Force sensor (Technical University Delft, The Netherlands). Changes in wound tension were measured by the ForceTRAP system. The ForceTRAP is a platform measuring forces from 0 to 20 N in three dimensions with an accuracy of 0.1 N. The Hook-in-Force is a force sensor measuring 0-15 N with an accuracy of 0.5 N. Maximum and mean forces were calculated for each suture technique and operator.

RESULTS

Mean maximum pulling force: 5.69 N (standard deviation [SD], 0.88) single, 7.25 N (SD, 1.33) vertical mattress, 8.11 N (SD, 1.00) horizontal mattress, 3.46 N (SD, 0.61) pulley, and 4.52 N (SD, 0.67) modified pulley suture. The mean force increase on the skin (substitute) ranged between 0.80 N (pulley) and 0.96 N (vertical mattress).

CONCLUSIONS

The pulley suture requires less pulling force compared with other techniques. The mechanical properties of sutures should be taken in consideration when choosing a technique to close wounds.

Forces on sutures when closing excisional wounds using the rule of halves

BACKGROUND

To close elliptical excisions, surgeons commonly use the rule of halves which involves initially closing of the middle portion of the wound, followed by closure of the remaining halves. Understanding the forces required for suturing such wounds can aid excisional surgery planning to decrease complications and improve wound healing.

METHODS

Following full thickness excision for removal of skin cancers, back wounds with 3:1 ratio of length-to-width were closed using the rule of halves. The force required to bring the wound edges into contact at the middle portion of the wound was measured, followed by the two bisected halves.

FINDINGS

The average force to close the center of the wounds averaged 3.7 N and was six times larger than that of the bisected halves. The forces to close the bisected halves were consistently small, and essentially negligible (<0.5 N) for ~50% of the cases.

INTERPRETATION

When planning excisional surgery to avoid complications such as tearing the dermis (cheese wiring), the use of special wound closure techniques (high tension and/or pully sutures, skin support or suture retention devices, etc.) should focus on the center suture only when using the rule of halves, as the remaining sutures require very low forces.