Variations of Extended Latissimus Dorsi Musculocutaneous Flap for Reconstruction of Large Wounds in the Extremity.

OBJECTIVE: The aim of the present study was to report a novel nomenclature system for extended latissimus dorsi musculocutaneous (LD) flaps. To evaluate the clinical application and surgical efficacy of the different extended LD flaps for large wounds in the extremities. METHODS: From January 2004 to December 2018, 72 consecutive patients who received extended LD flaps were retrospectively analyzed. Patients' ages ranged from 2 to 68 years with 37 males and 35 females. All wounds were extensive in either the upper or lower limbs, while the skin defect area ranged from 18 cm × 10 cm to 37 cm × 21 cm. Forty-one wounds were located in the calf, 18 in the foot and ankle, six in the shoulder and upper arm, four in the thigh, and three at the knee joint. Twenty-eight patients had fractures, and six of these patients with segmental bone defects (ranging in size from 3 to 7 cm) required secondary orthopaedic procedures. Single- and double-wing extended LD flaps were designed and harvested according to the shape of the wounds. RESULTS: The flaps received consisted of 64 single-wing and eight double-wing extended LD flaps, and the mean flap harvest time was 56.2 min. The donor sites were closed primarily for all patients. Additional subcutaneous veins were anastomosed to the recipient's vessels in 14 patients. The venous crisis was noticed on the first postoperative day in four cases. Two flaps were salvaged after emergency re-exploration, and another two patients' flaps were necrosed. In these two patients, lower limb amputation and extended LD flap on the other side were used, respectively, for the final treatment. The wounds healed well, providing reliable soft tissue coverage and good contour in the reconstructed areas. Six patients had segmental bone defects that required secondary orthopaedic procedures, two patients were repaired with vascularized iliac crest bone grafts, and another four patients were reconstructed by the Ilizarov technique. All the patients' bone defects achieved union and most patients achieved good functional recovery at the recipient site. The mean follow-up was 15.7 months (range, 10-56 months). No significant donor site morbidities limiting patients' daily activities occurred during the follow-up. Eight patients developed a donor site hypertrophic scar, three patients on the back, and five on the anterolateral thigh. CONCLUSION: Single- and double-wing extended LD flaps are simple and reliable methods for large skin and soft tissue defects in the extremity, with good functional and aesthetic results.

Role of Zinc in Mucosal Health and Disease: A Review of Physiological, Biochemical, and Molecular Processes.

Zinc is an essential trace element of all highly proliferating cells in the human body. It is essential to the development and growth of all organisms. Zinc plays a critical role in modulating resistance to infectious agents and reduces the duration, severity, and risk of diarrheal disease via improved regeneration of intestinal epithelium, improved absorption of water and electrolytes, increased levels of brush border enzymes, and, possibly, an enhancement in the immune response allowing better clearance of pathogens. On the cellular level, zinc finger motifs play various roles including diverse functions that involve specific gene expression for ion channels throughout the body. It maintains the function and the structure of the membrane barrier by contributing to host defense, which is particularly crucial in the intestines due to the continuous exposure to noxious agents and pathogens. Zinc deficiency is characterized by impaired immune function, loss of appetite, and growth retardation. More severe cases cause diarrhea, delayed sexual maturation, hair loss, eye and skin lesions, impotence and hypogonadism in males, as well as weight loss, taste abnormalities, delayed healing of wounds, and mental lethargy. The objective of this study is a critical review of the molecular and genetic regulation of zinc in various cellular processes and organs, the association between zinc and diarrheal disease, the recommended dietary zinc intake, and the effects of zinc deficiency on the human body.