Biomedical subjects

B Guyuron

Publications and source records attributed to B Guyuron.

At least 19 recordsLinked to original sources

PubMed2000

Supratip deformity: a closer look.

Supratip deformity, a hallmark of a poorly executed rhinoplasty or an inauspicious healing, continues to plague the novice often and the experts on occasion. A clinical and histopathologic study was conducted to search for the surgical causes of this deformity and its histologic presentation. An organized, logical management program was then developed. Clinically, supratip fullness was observed in both primary (26 of 298 patients; 9 percent) and secondary (40 of 112 patients; 36 percent) rhinoplasty candidates. In primary patients, the deformity was the result of inadequate tip projection (pseudodeformity), an overprojected caudal dorsum, a combination of both, or cephalically oriented lower lateral cartilages. In secondary patients, the deformity was caused by an underresected or overresected caudal dorsum, overresected midvault, underprojected tip (pseudodeformity), or a combination of some of these factors. The histopathologic evaluation demonstrated significant fibrosis in the supratip soft tissue of 14 of 16 patients undergoing secondary rhinoplasty without the injection of triamcinolone acetonide and in only 13 of 23 patients who underwent primary rhinoplasty (p<0.05). A supratip deformity can be eschewed by proper resection of the caudal dorsum, avoidance of dead space, restoration of adequate projection to the nasal tip, and an approximation of the supratip subcutaneous tissue to the underlying cartilage using a supratip suture, hence eliminating the dead space. If the problem is noted shortly after surgery, in the presence of collapsible consistency of the supratip tissue and adequate projection, the treatment is taping the supratip tissue as often as it is practical. If no favorable response is elicited in 6 to 8 weeks, thejudicious injection of a small amount of triamcinolone acetonide (0.2 to 0.4 cc of 20 mg/cc) in the deep subcutaneous tissue (not in the dermis) is done. The injection is repeated in 4-week intervals until the desired effect is achieved. If supratip fullness is the consequence of inadequate cartilage resection or inadequate tip projection, surgical correction is needed. The recalcitrant soft-tissue excess in the supratip area is resected, and the subcutaneous soft tissue is approximated to the underlying cartilage. If the dorsum was previously overresected, a cartilage graft to the caudal dorsum or midvault will create an optimal dorsal frame and reduce the potential for a recurrent supratip deformity.

Humans↗

PubMed1999

Shortening of the long forehead.

A long forehead disrupts the harmony among the facial components and may contribute to the semblance of facial aging. Slight forehead length disharmony on a senescent face can be corrected by placing the incision at the hairline, elevating the eyebrows through subcutaneous or subgaleal dissection, and removing excess skin without posterior scalp immobilization. For moderate to major reduction of the forehead length, the scalp is elevated back to the occipital region through a pretrichial incision, and relaxation incisions are made at a right angle to the vector of advancement. The entire scalp is then repositioned anteriorly, advancing the hairline caudally and shortening the forehead. Retraction of the scalp or excessive elevation of the eyebrows is prevented by anchoring the galeal fascia to the cranial bone using a bone-tunneling technique in one to three rows. The number of fixation rows is commensurate to the amount of advancement and rigidity of the scalp. The more immobile the scalp preoperatively, the more relaxation incisions and fixation tunnels are necessary. Following caudal repositioning of the scalp, the non-hair-bearing skin is excised, and a meticulous repair is done. These procedures have been performed in 180 patients with a high degree of satisfaction. Temporary hair loss was experienced in one smoker who underwent the most advancement through posterior scalp elevation and continued to smoke postoperatively. Also, on three patients in the subcutaneous forehead rhytidectomy group, two of whom were smokers, delayed healing was observed in the temple area because of compromised circulation requiring secondary revision.

Forehead↗

PubMed1998

Fire hazards and CO2 laser resurfacing.

The purpose of this study was to investigate the fire risk of laser resurfacing in the presence of supplemental oxygen. This study aims at defining safety parameters of variables such as laser energy level, oxygen flow rate, and "oxygen to laser target distance" when oxygen is delivered through a nasal cannula or nasopharyngeal tube. The typical operating room environment was simulated in the laboratory using the Yucatan minipig animal model. The energy source was a Coherent Ultrapulse CO2 laser. It was found that combustion did not occur at laser settings of 500 mJ, 50 W, 100 kHz, and a density of 5, used in conjunction with an oxygen flow rate of 6 liter/minute with the target area as close as 0.5 cm to the oxygen delivery. A total of 400 computer pattern generator treatments were delivered using this energy setting without observation of any combustion (p < 0.001). This provides evidence that while using even somewhat high laser settings and oxygen flow rate, laser induced fires can be avoided. We conclude that use of the laser in the presence of oxygen is safe, provided the target area is free of combustible fuels. Despite this assurance, laser mishaps are serious because they lead to both morbidity and mortality. It is our recommendation that close attention be constantly paid to all details, thus reducing the hazard potential of laser energy on local factors in an oxygen-rich environment.

Animals↗

PubMed1998

Delayed healing of rhytidectomy flap resurfaced with CO2 laser.

Combining facial rhytidectomy with laser resurfacing, theoretically, provides the best opportunity for achieving an optimal facial rejuvenation result. Previous studies have demonstrated the pernicious effect of a deep peel on a skin flap, but the safety of treating the rhytidectomy flap with laser has not been investigated. This study was conducted to investigate the safety of using these techniques concomitantly. Sixty sites were selected on three Yucatan minipigs, a species of swine chosen because of its hairless nature and opportunity to raise a true skin flap (without the panniculus carnosus). The healing time of 20 laser-treated sites without flap elevation was compared with that of 20 areas treated with laser following flap elevation, shortening (to emulate a more realistic rhytidectomy process), and repair. Twenty flaps were elevated and shortened without laser treatment to serve as a control. The CO2 laser parameters were set at 500 mJ, 50 watts, and a density of 5. Two passes were made to penetrate the upper dermis. The mean healing time for areas treated with laser alone was 12.05 days, ranging from 11 to 14 days. In comparison, the healing time for the laser-treated areas subsequent to flap elevation averaged 17.95 days, with a range of 14 to 24 days (p < 0.05). Two flaps treated with laser (10 percent) failed to heal completely in 24 days. At the time that all 20 of the areas treated solely with laser had re-epithelialized completely, only one of the flaps treated with laser had re-epithelialized completely (p < 0.001). A delay in healing, as well as return of pigment, was demonstrated in the distal portions of all flaps receiving laser treatment. The control flaps all healed normally except for a 5-percent superficial loss on a single flap. It was concluded from this study, and from clinical observation of delayed healing on six of seven patients who underwent concomitant rhytidectomy and laser resurfacing at a conservative laser setting, that laser resurfacing of the rhytidectomy flap is unsafe and results in delayed re-epithelialization. This combination should be avoided altogether or performed with extreme prudence on patients undergoing a deeper plane facial rhytidectomy or by using very low laser settings.

Animals↗

PubMed1998

Footplates of the medial crura.

The purpose of this combined prospective and retrospective study was to review the abnormalities of the footplates of the medial crura, their surgical correction, and the dynamic changes that result from footplate alteration. Prospectively, measurements of 40 footplates were obtained during 20 consecutive primary rhinoplasties. The distance between the footplates at their most posterocaudal position was measured, along with the thickness, length, and width of the footplates. The shape of the nostrils was also observed and correlated to the form of the footplates. The distance between the footplates ranged from 7.5 to 15 mm, the average being 11.4 mm. The length of the footplates ranged from 4 to 7.5 mm, the average being 5.81 mm. The thickness of the footplates averaged 1.06 mm, ranging from 0.80 to 1.5 mm. The width of the footplates ranged from 2.5 to 7.0 mm, averaging 4.48 mm. In a retrospective review of 295 consecutive rhinoplasties, footplates were altered in 76 cases (25.8 percent). Of these cases, 29 procedures (9.8 percent) were performed to narrow the columella base and to advance the subnasale: on 24 patients (8.1 percent), the goal of this maneuver was to narrow the columella base only; on 5 patients (1.7 percent), the operation was conducted to aid in increasing the tip projection, provide a better foundation for the tip, advance the subnasale caudally, and narrow the alar base. Asymmetry of the columella was corrected in 16 patients (5.4 percent), and footplates were resected primarily to reduce the tip projection in 2 patients (0.7 percent). A detailed analysis of the nasal base will dictate one of the following courses pertaining to footplate alteration. If the patient exhibits an overprojected tip and divergent footplates, the lateral portion of the footplates will be resected partially, then approximated. If the tip is underprojected or has normal projection, the divergent footplates will be approximated without resection. Should the subnasale and the base of the columella be protruding, the soft tissue between the footplates will be removed to avoid excess fullness in this site as a result of the approximation of the footplate. However, when the footplates are divergent, the columella base and nasal spine area are often retracted, setting an auspicious stage for approximation of the footplates without having to excise the soft tissue. This maneuver not only narrows the columella base, it also advances it caudally. Longstanding caudal deviation of the septum may also create asymmetry of the footplates, which will not respond to mere repositioning of the septum, and often requires repositioning of the footplates with mobilization and fixation to the contralateral footplates.

Cartilage↗

PubMed1998

Upper lateral splay graft.

Middle vault collapse narrows the internal nasal valve and impairs airflow through the nose. Loss of structural integrity of the upper lateral cartilaginous vault, the cause of the middle vault collapse, is classically corrected by inserting anterior spreader grafts, resulting in variable success. The desire to reconstruct the natural "T" of the upper lateral and septal cartilages culminated in the development of the upper lateral splay graft. The splay graft spans the dorsal septum but is deep to the left and right upper lateral cartilages. The intrinsic spring in the splay graft elevates each upper lateral cartilage with the septum as the fulcrum, thus correcting the middle vault collapse and opening the internal valve. The procedure, a physiologic substitute for the device "Breathe Right" applied externally, has been performed on nine patients and proved to be a prodigious functional boon to all of them. The powerful splay effect, however, can result in excessive widening of the caudal portion of the dorsum with imprudent use of the technique. Two case reports illustrate the subjective and objective improvement that was shared in all but one patient. Excess widening in one patient resulted in a suboptimal aesthetic improvement, although the functional objectives were met. Identification of suitable patients, preoperative assessment, choice of cartilage donor site, and the surgical technique are discussed. Improved internal valve function, predictability, and reliability are some of the distinct advantages of using a splay graft.

Adult↗

PubMed1998

Nasal osteotomy and airway changes.

The purpose of this prospective investigation was to evaluate the factors involved in the constricting effect of nasal bone osteotomy on the nasal airway. Immediately before the osteotomy, observations were made and recorded in regard to both the position of the inferior turbinates and the length of the nasal bones. During the osteotomy, the nasal bone movement was graded and the type of osteotomy was documented. The two types of osteotomy were defined as either high-to-low or low-to-low. Each side of the nose was assessed independently. Forty-eight consecutive patients, 8 men and 40 women, were included in this study, providing 96 nasal sides for evaluation. There were 42 normal, 32 short, and 22 long nasal bones. The patients with short nasal bones exhibited less diminution in the airway than those patients with normal nasal bones (p < 0.05). The position of the inferior turbinates was designated as anterior in 48 sites, 12 were considered normal, and 28 were deemed posterior. The narrowing of the airway was significant when the inferior turbinates were positioned anteriorly when compared with posteriorly positioned inferior turbinates (p < 0.05). Twenty-four nasal bones were shifted slightly, 48 intermediately, and 22 significantly. Major nasal airway constriction was observed when the medial positioning of the nasal bone was significant (p < 0.05). Eighty-four osteotomies were classified as low-to-low, and 12 were high-to-low. High-to-low osteotomies resulted in the least narrowing of the nasal passage (p < 0.005). It is concluded from this study that the nasal osteotomy does constrict the nasal airway in most incidences. The length of the nasal bones, the degree of nasal bone repositioning, the position of the inferior turbinates, and the type of osteotomy are definite factors contributing to airway narrowing after nasal bone osteotomy.

Adolescent↗

PubMed1997

The aging nose.

Mature adult rhinoplasty requires more sophisticated planning and flawless execution in order to achieve an optimal result. The improvement not only engenders a more pleasing feature, it also provides approximately 5 years' rejuvenation to the face. These patients possess thin skin, weak support structures, and vulnerable nasal function, rendering the rhinoplasty more enigmatic. The medical and emotional issues should be resolved prior to surgery.

Adult↗

PubMed1997

The fate of preserved autogenous bone graft.

Certain clinical conditions exist in which a section of cranial bone is removed but not immediately replaced at the initial procedure. Preservation of this bone can provide a valuable autogenous donor source for a future reconstructive procedure. The purpose of our study was to compare the volume retention of fresh autogenous bone with that of preserved autogenous bone as inlay and onlay cranial grafts. Two bone grafts were harvested from the skull of 15 adult New Zealand White rabbits. The graft volumes were calculated, and the graft were preserved in a normal saline-antibiotic solution at -20 degrees C. Three months later, during the second procedure, a fresh graft was harvested and then placed in the preexisting occipital defect as an inlay graft. Also at this time, the preserved grafts were placed, one as an inlay graft in the fresh occipital defect and the other as an onlay graft in the frontal region. The animals were sacrificed 3 months later, and the percentage of graft volume retention was determined. The fresh inlay grafts had a mean volume retention of 85.1 percent, while the preserved inlay nad onlay grafts had 61.8 and 75.9 percent mean volume retention, respectively. It is concluded that while fresh cranial autograft remains the "gold standard" for craniofacial reconstruction, preserved autogenous cranial bone is a viable alternative for inlay and onlay grafting of the craniofacial region.

Analysis of Variance↗

PubMed1997

Refinements in endoscopic forehead rejuvenation.

Endoscopic forehead technique provides an effective method for rejuvenation of the upper face. Distinct advantages of this technique over classic methods of forehead rejuvenation such as coronal or subcutaneous approaches include significant reduction of incisional scars. Described here are three refinements related to (1) control of hair, (2) differential release of the periosteum, and (3) advanced fixation methods. Control of hair can be achieved simply by braiding and the use of an Endoscopic Access Device. Extensive release of the periosteum and arcus marginalis is recommended laterally, while elevating the medial periosteum either intact or with conservative release. Different and technologically more advanced fixation methods are described to provide better control of elevated forehead. Incorporation of these refinements strives to optimize aesthetic results while minimizing operative morbidity. These refinements have been implemented during the care of 29 patients and have proven to be of major value in achieving greater patient satisfaction and technical advancement.

Endoscopes↗

PubMed1997

Ear projection and the posterior auricular muscle insertion.

Prominent ears is a common congenital anomaly affecting approximately 5 percent of the general population. The etiology has been attributed to three basic deformities in the ear structure: valgus of the concha with a cranioauricular angle greater than 40 degrees, underfolding of the anthelix, and rarely, hypertrophy of the concha. It is believed that by virtue of its insertion onto the ponticulus, the cranial surface of the concha, the posterior auricular muscle may function to pull the auricle back toward the head. A proximally (anteromedially) displaced insertion site would decrease the length of the effective momentum of the muscle, leading to protrusion of the auricle. This study was conducted to determine if indeed a relationship between the posterior muscle insertion site and ear projection could be established clinically by measuring these parameters intraoperatively in patients presenting for otoplasty and in patients without prominent ears who required conchal cartilage grafts for other procedures.

Adolescent↗

PubMed1997

Secondary rhytidectomy.

A postoperative questionnaire was sent to all secondary rhytidectomy patients inquiring about their social and physical recovery time, complications related to either the initial or secondary surgery, and the onset of any new medical problems or the commencement of any new medications between the two surgeries. The overall satisfaction rates for both surgeries, time interval between the two operations, and their perception of the years of youthful appearance gained from either operation were also investigated. The overall satisfaction rate was slightly higher for the secondary facial rhytidectomy (4.49) than for the primary rejuvenation of the face (3.97) (p < 0.06). Patients perceived themselves as looking an average of 9.31 years younger following primary surgery, as compared to an average of 10.19 years younger following the secondary rhytidectomy (p < 0.50). The average time interval between the primary and secondary rhytidectomy surgeries was 8.48 years (range = 1 to 16 years). Twenty-nine ancillary procedures were performed during the initial rhytidectomy and 70 ancillary procedures were selected during the secondary rhytidectomy (p < 0.001). There was no statistically significant difference for the physical and social recovery time between the two procedures. Fourteen of 33 patients (42.4 percent) requiring a secondary rhytidectomy had developed a new medical problem prior to the second surgery (p < 0.001) and 19 patients (57.6 percent) were started on a new medication (p < 0.001). It was concluded from this study that the secondary rhytidectomy patients are more inclined to be satisfied (approaching statistical significance), are more likely to undergo ancillary procedures, and, being 10 years older, are more prone to have medical problems with deleterious effects on surgery and to be on medications with potential ill effects. Also, observations have been made that the previous scars pose some limitations, with the anatomical changes from the previous surgeries often requiring masterful planning and execution. Skin circulation is, in general, superior, enduring more tension.

Adult↗

PubMed1997

Rejuvenation of the upper face. A logical gamut of surgical options.

The prime objective of forehead rejuvenation is to correct the factors that accentuate the impression of aging, namely, eyebrow ptosis, glabella frown lines, forehead wrinkles, and asymmetry. Options for forehead rejuvenation are undergoing a renaissance. With the wide variety of choices currently available, accurate analysis of the presenting problem is mandatory so that the appropriate surgical technique can be chosen. The less invasive endoscopic procedures have a low morbidity rate and great patient satisfaction. Not all patients are candidates for these procedures, however. A thorough knowledge of alternative methods, including botulinum injection, fat injection, fat grafting, and subcutaneous approaches to the brow, are necessary if optimal aesthetic results are to be accomplished. Having an armamentarium of forehead rejuvenation techniques is, therefore, the key to individualizing treatment for each patient.

Adipose Tissue↗

PubMed1997

Problems following genioplasty. Diagnosis and treatment.

Both alloplastic and osteoplastic genioplasty harbor the potential for outcomes that may mandate a revision. A successful reversal of this often enigmatic situation requires a thorough and trenchant analysis of the clinical condition, as well as the emotional motive leading the patient to seek a revision surgery. The selected corrective procedure has to offer the highest potential for success with the least invasion possible. The goals should be set with the scar tissue, distorted anatomy, and reduced circulation in mind. The limitations should be recognized, and the related concerns should be shared with the patient. Many of these, often imperfections and sometimes gross deformities, can be corrected, as long as the problem is identified and a suitable solution is culled out.

Facial Asymmetry↗

PubMed1996

Resection of bilateral orbital and cranial base basal cell carcinoma with preservation of vision.

The surgical resection of skull base tumors often presents technically challenging problems and can result in major deformities. In planning the operation, each individual patient must be evaluated not only with respect to the extent of the disease, but also with respect to the functional losses, which may severely affect the patient's quality of life. The patient presented is an elderly woman with a malignant anterior skull base basal cell carcinoma and multiple recurrences. The tumor extended to the orbits bilaterally, resulting in blindness in the right eye. The objective was to resect the tumor from the skull base and the orbits, while preserving vision in the left eye. Utilizing intraoperative frozen sections, extensive tumor resection in the left orbit was accomplished without compromising vision. This was followed by the reconstruction of the eyelids and periorbital tissues. Exenteration of the right orbit, anterior craniectomy, and partial dural resection were also performed. Ten years later, the patient remains free of tumor recurrence and has good vision in her left eye.

Aged↗

PubMed1996

Management of an extensive cervicofacial lymphovenous malformation of the maxillofacial region.

The operative approach to extensive vascular anomalies of the maxillofacial region with significant skeletal involvement demands considerable preoperative planning and orthodontic intervention guided by a creative surgical design. A case of a 17-year-old male with a middle and lower face lymphovenous malformation, requiring a complex orthodontic and surgical approach, is reported here. Details regarding the preoperative examination, orthodontic maneuvering, and the surgical procedures are given. An overview of the classification and clinical implications of craniofacial vascular anomalies is also presented.

Adult↗

PubMed1996

The role of DDAVP (desmopressin) in orthognathic surgery.

Desmopressin (1-deamino-8-D-argininevasopressin, DDAVP) is a synthetic analog of the antidiuretic hormone L-argininevasopressin. DDAVP has been shown to increase the plasma concentration of endothelial factor VIII, thus increasing coagulant activity. There is evidence from controlled clinical trials indicating that DDAVP can reduce blood loss and transfusion requirements for individuals with normal coagulation profiles undergoing various surgical procedures. This study was conducted to evaluate the efficacy of the DDAVP in reduction of blood loss during orthognathic surgery. Twenty patients, 15 females and 5 males, undergoing bimaxillary osteotomy were randomized into two groups of ten. Perioperatively, group 1 patients received 20 micrograms of DDAVP infused over one-half hour. Group II patients did not receive DDAVP. Hypotensive anesthesia (mean arterial pressure < 60 mm Hg) was routinely employed for both groups. On average, the blood loss in group I patients was 144 ml less per patient than group II patients (p < 0.50). Only 2 of 10 patients in group I lost in excess of 750 ml, while 6 to 10 group II patients experienced blood loss greater than 750 ml (p < 0.20). The average postoperative hematocrit for patients in group I dropped by 6.17 of the preoperative mean hematocrit (p < 0.001). The average drop in hematocrits among the group II patients was 11.61 (p < 0.001). When collated, this hematocrit drop of 11.61 for group II and 6.17 for group I (recipients of DDAVP) proved to be significantly different (p < 0.01). It is concluded from this study that patients receiving a standard dose of DDAVP prior to bimaxillary osteotomy would experience reduced intraoperative blood loss, providing that blood pressure is well controlled and fluid replacement is carefully managed. No significant adverse side effects of desmopressin acetate were observed.

Blood Loss, Surgical↗

PubMed1996

Comparison of polydioxanone and polyglactin 910 in intradermal repair.

A prospective clinical study was undertaken to compare the results of intradermal layer closure using two popular absorbable suture materials, polydioxanone and polyglactin 910. On an alternating basis, 6-0 polydioxanone and 6-0 polyglactin 910 were used to repair 80 surgical sites of the temple and occipital regions in 20 patients undergoing facial rhytidectomy. In all instances, the superficial skin layer was repaired with 6-0 plain catgut. These sites were evaluated by a double-blind method for erythema, induration, infection, scar spread, and hypertrophic scarring at approximately 5 months and at least 1 year postoperatively. Scar spread was indicated at widths greater than 1 mm. Any raised scar was labeled hypertrophic. Scar spread, as defined above, was observed in 6 of 38 incisions repaired with polyglactin 910, and 3 sites developed scar hypertrophy. Conversely, 3 of 38 incisions closed with polydioxanone revealed scar spread (p < 0.25), and 3 were hypertrophic (p < 0.35). Sixty-one sites healed with undiscernible scars. This study does not disclose any statistically significant difference in the quality of the scars when polyglactin 910 is used compared with polydioxanone.

Cicatrix↗