Enhancement of tissue expansion by anticontractile agents

To evaluate the effect of anticontractile agents on the rate of tissue expansion, guinea pig back skin was expanded while being treated with various anticontractile agents. Expansion was carried out using standard percutaneous inflatable skin expanders modified by the addition of a catheter to deliver the anticontractile agents papaverine or cytochalasin D. Expansion proceeded for 25 days with one or other of the substances being infused through the catheter; saline was used in a separate control group. Measurements of the rate and extent of expansion showed that there was a statistically significant increase in these parameters for the experimental groups as compared with saline controls. Histologic examination of the expanded tissue suggests that the cellular basis for this phenomenon may involve the relaxation or inactivation of contractile fibroblasts in the fibrous capsule surrounding the expander.     

Total reconstruction of a two-compartment scrotum by tissue expansion

A case report is presented showing the reconstruction of a two-compartment scrotum out of hair-bearing perineal skin following a severe degloving injury of the scrotum and testicles. We feel that this is an appropriate procedure to be used in patients who have lost the testicles and scrotum traumatically, either one or both testicles, or in the situation where both testicles have been spared. Aesthetically, the result in this patient is superior to skin grafting and should be readily reproducible.     

Accelerating tissue expansion by application of topical papaverine cream

The rate of tissue expansion can be accelerated by papaverine through a special delivery system, according to an early report. Because the delivery system was complex and inconvenient, another means of administrating papaverine was tested to observe the rate of tissue expansion. In this study, 24 miniature pigs were divided equally into three groups. Four 150-ml silicone expanders were implanted into each pig in groups A and C. Four modified rectangular silicone expanders were also implanted into each animal in group B. During the expansion process, 1 g of 2% hydrochloride papaverine cream was applied topically onto the surface of each pig's expanding skin in group A two times daily, and hydrochloride papaverine solution was injected into the outer shell of each modified expander in group B weekly. Group C acted as the control group. The mean sum of the first four times of saline water volume that was injected into the expanders was 142.42 +/- 5.6 ml in group A, 128.72+/-4.8 ml in group B, and 106.38+/-3.28 in group C. There were statistical differences among the three groups. The mean sum of volume saline water that was injected into hind expanders was 137.51 +/- 5.1 ml in group A, 120.35 +/- 3.6 ml in group B, and 102.63 +/- 4.76 ml in group C, and there was a statistical difference among the three groups as well. There was no statistically significant difference in the thickness of fibrous capsules among the three groups. This study shows that the rate of tissue expansion can be accelerated by topical application of papaverine cream, and the rate is better than the rate of tissue expansion induced by the special drug delivery system.     

Tissue expansion in head and neck reconstruction

The present study reviews our clinical experience with tissue expansion in head and neck reconstruction. The clinical series consists of 33 expansions performed in 29 patients between 1983 and 1986. The results of tissue expansion in the head and neck were distinguished by a high complication rate, necessitating some revision in the original treatment plan in 48 percent of patients. Despite this high incidence of complications, sufficient tissue was generated to successfully complete the planned reconstruction in 79 percent of patients. Specific complications were observed with particularly high frequency within distinct anatomic sites. The highest incidence of complications occurred in the cheek and neck (69 percent) and forehead (50 percent) regions. Complications in the eyelid region (33 percent) and scalp (17 percent) were less common. Implant exposure was the most frequently observed complication. Other sequelae noted in this series included intractable pain, infection, and bone resorption.     

Surface-area increase in tissue expansion

In this paper, the subject of surface-area gain in tissue expansion is approached from three sides. With the help of a mathematical approach, the theoretical increase in surface area was calculated in relation to the specifications of the expanders. In an in vitro model, these mathematical data were confirmed to be reliable. To determine the real surface-area gain that takes place in vivo, measurements on pigs were performed. It appears that only about 35 percent of the mathematically expected increase in surface area takes place. Moreover, a clear difference was observed between the surface-area gain for the different shapes of tissue expanders.     

A hemorrhagic hazard of tissue expansion

A case of delayed acute hemorrhage complicating tissue expansion of the scalp is presented. The likely mechanism was erosion of an occipital artery by the edge of the expander, and the risk of a similar occurrence should be considered in all patients undergoing tissue expansion.     

Animal models of human tissue expansion

Although tissue expansion is being used extensively in humans, many fundamental scientific questions remain to be addressed which can best be answered using an animal model. Presently, no single animal has been identified for research of this kind which is comparable both subjectively and objectively to humans. This study evaluates the skin of the rat, guinea pig, pig, and dog and identifies the dog as the best model based on biomechanical and practical considerations.     

Correction of cryptotia using tissue expansion

The anatomy and surgical correction of cryptotia are reviewed. Another technical procedure using retroauricular tissue expansion is presented. This method allows release of the auricle and construction of the auriculocephalic sulcus without the problems associated with older soft-tissue techniques, e.g., incomplete correction, multiple scars, poor color match of skin grafts, and donor-site morbidity.