Invisible scar endoscopic thyroidectomy by the dorsal approach: experimental development of a new technique with human cadavers and preliminary clinical results.

BACKGROUND: A unilateral gasless single-surgeon videoendoscopic thyroidectomy procedure using a dorsal cephalic approach from the scalp with the option for a bilateral approach was developed with human cadavers and a porcine model for access training. The final preclinical trials and the first three clinical cases are described in detail. METHODS: Preclinical evaluation and training for the procedure were conducted with fresh human cadavers. The procedure was defined precisely by a sequence of nodal points initiating surgical steps. A quality score was developed by issuing each important anatomic structure a specific organ value and a factor for positive identification, inability to identify a given anatomic structure, spare it (meaning omit causing a lesion) or injure the structure. The quality of each operation was expressed as a single number or quality score value, calculated by summing the points achieved for the individual anatomic structures. The results of the procedures were controlled by prospective video documentation and autopsy. After conclusion of the preclinical training, the operation was performed for patients. The reported patients are part of a feasibility study approved by the institutional review board of the University of Munich. RESULTS: Nodal points were helpful in preparation for the operation by mental training. During the procedure, they helped to guide the preparation in the neck, where the working space must first be created on the way to the target organ. The surgical quality score improved over the first three cases and reached the maximum score, which was reproducible every time after that. It showed that the dorsal approach from the scalp to the thyroid gland is easily achievable without complications. The technical challenge is exposure of the recurrent laryngeal nerve (RLN) and the parathyroid glands. There was no difference between the results achieved by the resident and the senior surgeon. Preclinical training was good preparation for hemithyroidectomy in patients. All cases could be managed without postoperative hemorrhage or impairment of the parathyroid or the RLN. CONCLUSIONS: Videoendoscopic thyroidectomy by the dorsal approach is feasible in both human cadavers and patients. It leaves no visible scars. Nodal points are helpful for executing a new operation. The surgical quality score is a complex and objective measure of ability to deal with the procedure. Further clinical studies are required for evaluation of this new procedure.

Dehydroepiandrosterone restores depressed peripheral blood mononuclear cell function following major abdominal surgery via the estrogen receptors.

OBJECTIVE: Peripheral blood mononuclear cell (PBMC) dysfunction occurs following major abdominal surgery and correlates with an increased rate of septic complications. Studies have shown that dehydroepiandrosterone (DHEA) restores cell-mediated immune responses after trauma-hemorrhage in mice. Nonetheless, it remains unknown whether DHEA has any salutary effects on depressed PBMC function in surgical patients. DESIGN: Laboratory experiment. SETTING: University laboratory. PATIENTS: Fifteen patients undergoing major abdominal surgery. INTERVENTIONS: Blood samples were obtained preoperatively and 2 hrs postoperatively. MEASUREMENTS AND MAIN RESULTS: PBMCs were cultured with 33% plasma in the presence or absence of DHEA (10(-10) M, 10(-8) M physiologic concentration, 10(-6) M, 10(-5) M). In an additional set of samples, the estrogen receptor antagonist tamoxifen (10(-6) M) was added. The release of proinflammatory cytokines (interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha) was measured in the supernatants by enzyme-linked immunosorbent assay. Abdominal surgery resulted in depressed interleukin-1beta and tumor necrosis factor-alpha release by PBMC. Addition of DHEA to the culture medium, however, significantly improved the release of interleukin-1beta and tumor necrosis factor-alpha and stimulated the interleukin-6 release capacity of PBMC. This effect was most pronounced for a concentration of 10(-5)M DHEA. The immunomodulatory effect of DHEA on PBMC cytokine release was completely blocked by tamoxifen. In contrast, the modulatory effect of DHEA was enhanced by the addition of postoperative plasma. CONCLUSIONS: DHEA stimulates proinflammatory cytokine release capacities of human PBMCs following major abdominal surgery. The estrogen receptor appears to be involved in mediating the immunomodulatory effect of DHEA. Thus, DHEA might be a useful adjunct for preventing immunosuppression in surgical patients.

Physiological levels of 5 alpha-dihydrotestosterone depress wound immune function and impair wound healing following trauma-hemorrhage.

HYPOTHESIS: Studies indicate that a depressed wound immune function contributes to an increased rate of wound complications and impaired wound healing following trauma-hemorrhage (T-H). Androgen, ie, 5 alpha-dihydrotestosterone, is responsible for producing the depressed systemic cell-mediated immune responses following T-H in males. The aim of the present study was to determine whether depletion of 5 alpha-dihydrotestosterone in males before T-H has any salutary effects on wound immune cell function and wound healing in male mice following T-H. DESIGN: Mice were castrated or sham castrated 14 days before midline laparotomy (ie, tissue trauma) and subcutaneous polyvinyl sponge implantation, followed by hemorrhage (mean +/- SEM blood pressure, 35 +/- 5 mm Hg for 90 minutes and resuscitation) or sham operation. At 24 hours thereafter, wound immune cells from the sponges were harvested and cultured with lipopolysaccharide A. Release of interleukin 1 beta (IL-1 beta) and IL-6 (in picograms per milliliter) was determined in the supernatants by enzyme-linked immunosorbent assay. In addition, IL-6 was assessed at the wound site by immunohistochemistry. Ten days after T-H, wound-breaking strength was measured. RESULTS: Precastration prevented the significantly suppressed capacity of wound immune cells to release IL-1 beta and IL-6. In addition, precastration normalized the elevated IL-6 expression at the wound site in the T-H mice. Moreover, wound-breaking strength was improved in castrated mice 10 days after T-H. CONCLUSIONS: Male sex steroids appear to be responsible for wound immune cell dysfunction following trauma and severe blood loss. Because decreasing androgen levels resulted in improved wound healing, our results suggest that the use of androgen receptor-blocking agents, eg, flutamide, following T-H might represent a novel adjunct for decreasing the rate of wound complications under those conditions.

L-arginine: a unique amino acid for improving depressed wound immune function following hemorrhage.

OBJECTIVE: To determine whether L-arginine has any salutary effects on wound immune cell function following trauma-hemorrhage. BACKGROUND: Depressed wound immune function contributes to an increased incidence of wound infections following hemorrhage. Although administration of L-arginine has been shown to restore depressed cell-mediated immune responses following hemorrhage potentially by maintaining organ blood flow, it remains unknown whether L-arginine has any salutary effects on the depressed local immune response at the wound site. METHODS: Male mice were subjected to a midline laparotomy and polyvinyl sponges were implanted subcutaneously in the abdominal wound prior to hemorrhage (35 +/- 5 mm Hg for 90 min and resuscitation) or sham operation. During resuscitation mice received 300 mg/kg body weight L-arginine or saline (vehicle). Sponges were harvested 24 h thereafter, wound fluid collected and wound immune cells cultured for 24 h in the presence of LPS. Pro- (IL-1 beta, IL-6) and anti-inflammatory (IL-10) cytokines were determined in the supernatants and the wound fluid. In addition, wounds were stained for IL-6 immunohistochemically. In a separate set of animals, skin and muscle blood flow was determined by microspheres. RESULTS: The capacity of wound immune cells to release IL-1 beta and IL-6 in vitro was significantly depressed in hemorrhaged mice receiving vehicle. Administration of L-arginine, however, improved wound immune cell function. In contrast, in vivo the increased IL-6 release at the wound site was decreased in L-arginine-treated mice following hemorrhage. Moreover, IL-10 levels were significantly increased in the wound fluid in hemorrhaged animals receiving L-arginine compared to vehicle-treated mice. In addition, the depressed skin and muscle blood flow after hemorrhage was restored by L-arginine. CONCLUSIONS: Thus, L-arginine might improve local wound cell function by decreasing the inflammatory response at the wound site. Since L-arginine protected wound immune cell function this amino acid might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications following hemorrhage.