Jack B. Robinson

Importance of the depressor septi nasi muscle in rhinoplasty: anatomic study and clinical application.

An active depressor septi muscle can accentuate a drooping nasal tip and shorten the upper lip on animation. We have found that dissection and transposition of the depressor septi muscle during rhinoplasty can improve the tip-upper lip relationship in appropriately selected patients. Although the anatomy of the depressor septi muscle has been described, the anatomic variations of this muscle have not been previously reported. The goals of this study were two-fold: (1) to define the anatomic variations of the depressor septi muscle using 55 fresh cadaver dissections and (2) to develop a clinically applicable algorithm for modification of this muscle during rhinoplasty in those patients with a short upper lip and/or tip-upper lip imbalance. Fifty-five fresh cadavers were dissected, and the anatomic variations of the depressor septi muscle were recorded. Three variations of the depressor septi muscle were delineated: type I inserted fully into the orbicularis oris (62 percent); type II inserted into the periosteum and incompletely into the orbicularis oris (22 percent); and type III showed no, or rudimentary, depressor septi muscle (16 percent). Sixty-two patients over a 4-year period (from 1995 to 1999) were identified preoperatively with a hyperactive depressor septi diagnosed by a descending nasal tip and shortened upper lip on animation. These patients underwent dissection and transposition (not resection) of the paired depressor septi during rhinoplasty with improvement or correction of the tip-upper lip imbalance in 88 percent of cases. The anatomic study, surgical indications, rationale for the operative technique, and clinical cases are presented. Dissection and transposition of the depressor septi is a valuable adjunct to rhinoplasty in patients with a type I or II muscle variant.

An anatomic study of the internal mammary veins: Clinical implications for free-tissue-transfer breast reconstruction

&NA; The anatomy of the internal mammary vessels is poorly understood and thought to be unreliable clinically for use as a recipient vein in free‐tissue‐transfer breast reconstruction. This study of 10 fresh cadaver thoracic cavities demonstrated by anatomic and dye resection studies that the internal mammary veins become smaller (≤2 mm) distally (fourth rib) and bifurcate [left (90 percent) > right (40 percent)], becoming unsuitable for consistent venous anastomoses at or below the fourth interspace. Furthermore, this study suggests that the most consistent interval is the third rib, which offers an appropriate recipient vein (40 percent ≥ 3 mm on the left and 70 percent ≥ 3 mm on the right). However, at the fourth interspace, 20 percent of the cadaver specimens had a vein on one side that was 1 mm or less and therefore unsuitable as a recipient. This enhanced understanding of the anatomy (size, location, and consistency) of the internal mammary recipient veins offers our patients another recipient option to enhance the safety and technical ease of microvascular breast reconstruction.

An analysis of silicone gel-filled breast implants: Diagnosis and failure rates

&NA; This retrospective review analyzed 180 women who underwent explantation of 357 silicone gel‐filled breast implants from September of 1991 to January of 1995. Implant status, including shell integrity and implantation times, was determined at the time of explantation. The age range of the patients was 25 to 75 years, with a mean age of 47 years. The age of the implants ranged from 0.5 to 24 years, with a mean age of 10.5 years. Of the 292 implants with known and documented integrity status, there were 102 intact, 76 unruptured with signs of leakage, and 114 ruptured. The frequency of implant rupture significantly increased with implant age. The average age of rupture was 13.4 years. The average age of signs of leakage was 10.1 years. There were no significant differences in failure rates among the implant types of four manufacturers. Analysis of both mammography and magnetic resonance imaging (MRI) as diagnostic modalities for differentiating intact implants, implant leakage, and implant rupture was performed. Standard mammography was less reliable in diagnosing implant leakage or rupture (sensitivity, 55 percent; specificity, 69 percent) than MRI (sensitivity, 72 percent; specificity, 82 percent). In conclusion, implant rupture occurred at a significantly increasing rate with implant age (10 to 15 years). These findings were independent of implant type or manufacturer. Mammography alone is a below‐average diagnostic tool for detecting leakage or rupture, whereas MRI is a more accurate modality. (Plast. Reconstr. Surg. 102: 2304, 1998.)

Comparative lipoplasty analysis of in vivo-treated adipose tissue.

A comparative histologic and chemical analysis was undertaken of adipose tissue treated in vivo with traditional, ultrasound-assisted, and external ultrasound-assisted lipoplasty. A series of six healthy women undergoing elective liposuction according to the superwet technique using a 1:1 infiltration ratio with the estimated quantity of fat to be removed was included in the study. Four separate regions on each patient were treated independently in vivo with traditional liposuction, internal ultrasound-assisted liposuction, or external ultrasound-assisted liposuction for 7 minutes. External massage was used as a control. Four separate specimens of adipose tissue from each patient were assessed for cellular disruption using blinded histologic evaluation. The remainder of tissue was centrifuged to separate the aqueous phase from the cellular components and then spectrophotometrically analyzed for creatinine kinase and glycerol 3-phosphate dehydrogenase activity as markers of cellular disruption. Histologic analysis confirmed 70 to 90 percent cellular disruption with internal ultrasound-assisted liposuction. Suction-assisted and external ultrasound-assisted liposuction showed 5 to 25 percent disruption, whereas massage controls showed only 5 percent. Only internal ultrasound-assisted liposuction showed 5 to 20 percent thermal liquefaction. Absorbance analysis showed creatine kinase activity (sigma units) greatest in ultrasound-exposed tissue. Both external and internal ultrasound-assisted liposuction gave creatine kinase levels 28 to 33 percent greater than suction-assisted liposuction, which varied only 10 percent from controls. Glycerol 3-phosphate dehydrogenase activity was 44 percent greater for internal ultrasound-assisted liposuction than that detected with suction-assisted liposuction. Glycerol 3-phosphate dehydrogenase activity with external ultrasound-assisted liposuction and massage did not vary much from each other, at only 14 percent and 11 percent activity compared with internal ultrasound-assisted liposuction, respectively. Histologic and enzyme analysis of the different types of liposuction and their effect on adipocyte cellular disruption revealed no significant effect of external ultrasound or massage on the adipocytes. Further experimental studies are necessary to evaluate the role and efficacy of alternative techniques for body contouring.

Frontal sinus obliteration: a comparison of fat, muscle, bone, and spontaneous osteoneogenesis in the cat model.

The obliteration of the frontal sinus is frequently necessary in the appropriate treatment of trauma, chronic infection, and benign tumors, but the various methods have not been directly compared previously. This study compares four treatment groups (seven cats per group) specifically of implantation of autologous fat, muscle, and bone and spontaneous osteogenesis done using a strictly standardized operative technique in an unfractured, uninfected feline frontal sinus model. All methods studied were effective in sinus obliteration; however, significant morbidities occurred at the donor sites when autologous tissue transplantation was used. Therefore, spontaneous osteogenesis appears to be the method of choice for frontal sinus obliteration.

the Tissue Effects of Ultrasound-assisted Lipoplasty

The objective of our study was to investigate the effects of ultrasonic energy on tissues, using a porcine model, performed under various instrumental and procedural parameters. Domestic pigs were anesthetized and prepared for surgery. An incision was made on the side of the hip randomly assigned to the right or left side. Tumescence solution was infiltrated via a blunt tip, small diameter cannula, followed by performance of standard liposuction. On the contralateral side, a similar incision was made. For ultrasonic liposuction experiments without the sheath, a percutaneous introducer was inserted into the incision, which was protected at the entry site from contact with the cannula. Tumescence solution was infiltrated via a blunt tip, small diameter cannula, and then the site was treated with ultrasonic energy at maximum output from the machine with liposuction concurrent through the hollow cannula. The experiments with the sheath did not require a pretreatment with tumescence solution but consisted of tumescence solution pumped through the sheath at a low infusion rate, with concurrent treatment utilizing ultrasonically assisted liposuction through the central lumen of the cannula. In all cases, the lipoaspirate was preserved for biochemical analysis. After treatment, the pigs were euthanized, and samples for histopathology were taken. The pigs were then perfused with a radio-opaque solution through the left ventricle following preperfusion with saline. The groups were ultrasound-assisted liposuction with sheath (n = 3), ultrasound-assisted without sheath (n = 4), and tumescence alone (n = 1), with standard liposuction performed on the contralateral side for all ultrasound-assisted liposuction animals. The lipoaspirates from the ultrasonically assisted liposuction with the sheath showed significantly less blood loss (measured as hemoglobin in the aspirate) than standard liposuction (p = 0.012) at comparable levels of fat (measured as triglycerides in the aspirate). The lipoaspirates from ultrasound-assisted liposuction without the sheath showed blood loss comparable to that experienced with standard liposuction. The ratio of hemoglobin to triglyceride was lowest in the ultrasound-assisted group with (p = 0.01) and without (p = 0.06) the sheath when compared to traditional liposuction. In both of these treated groups, the radiograms of the perfused areas showed significantly less vascular disruption when compared with suction-assisted liposuction. Histopathologic examination of specimens taken from various treated areas showed substantial tissue damage comparable in ultrasound- and suction-assisted liposuction treated groups. This preliminary experimental study showed that ultrasound-assisted lipoplasty is comparable to traditional suction-assisted lipoplasty. Treatment with ultrasound provided more significant hemoglobin/triglyceride ratios, indicative of more lipid aspirated per hemoglobin lost, and better preservation of vascular tissues as demonstrated by our perfusion studies. Treatment with the sheath showed a significantly lower hemoglobin release with a diminished volume infused into the subcutaneous space during the procedure.

Patency of different arterial and venous end-to-side microanastomosis techniques in a rat model

Microvascular anastomotic patency is the most important factor in determining a successful outcome in freeflap transfers. End‐to‐end and end‐to‐side techniques have been shown to provide equivalent arterial patency rates in clinical and basic science studies, and end‐to‐side anastomoses have been used extensively in microsurgical reconstruction. Nevertheless, the effect of venotomy shape on the patency of venous end‐to‐side anastomoses has not been previously reported. The purpose of this study was to compare the patency rates of end‐to‐side anastomoses using different techniques in both arteries and veins. In total, 104 Sprague‐Dawley rats were subdivided into four groups. The rats were anesthetized, and anastomosis was performed on either the femoral artery or vein on the right with the left used as control. Vesselotomy was varied between an end‐to‐side hole and an end‐to‐side slit with patency measured immediately following surgery and at 2 weeks. No significant difference in patency or histology between these techniques was demonstrated in any group. We conclude there is no difference in patency rate between the two techniques in arterial or venous vesselotomies; however, in small vessels < 1.5 mm, the slit technique is technically easier, and clinical recommendations are given. (Plast. Reconstr. Surg. 105: 156, 2000.)

Lipid infiltration as a possible biologic cause of silicone gel breast implant aging

&NA; The cause of silicone gel implant aging and rupture is not known. Recent reports indicate the failure rate is higher than previously published, and implant aging and rupture may be due to progressive mechanical deterioration of the outer vulcanized silicone shell. It is known that lipids are absorbed by the hydrophobic silicone elastomer, and lipid infiltration causes mechanical attenuation and possible failure of the elastomer. The purposes of this article are to analyze the silicone envelope/gel of explanted prostheses and the silicone elastomer of other medical grade silicone devices for lipid content and to suggest its possible role in implant aging and rupture. We assayed 33 ruptured silicone breast implant shells (mean age 13.1 years; range 8 to 26 years) and 8 medical grade silicone elastomer devices (mean age 3.7 years; range 3 months to 12 years) for evidence of lipid infiltration using thin layer chromatography. These were compared with control group assays from two nonimplanted silicone gel implants and one unused Silastic catheter. Ninety‐eight percent of implants and other previously implanted silicone devices were found to have evidence of lipid infiltration compared with none in nonimplanted controls (p < 0.005). We conclude that lipids infiltrate the outer silicone shell and may be a factor related to breast implant aging and rupture due to progressive mechanical weakening of the outer silicone shell. (Plast. Reconstr. Surg. 101: 64, 1998.)

Hemodynamics, electrolytes, and organ histology of larger-volume liposuction in a porcine model.

Liposuction is a procedure that allows the surgical removal of excess adipose tissue in healthy individuals. Lipoplasty is commonly performed with few clinical side effects. However, with increased lipoaspirate volumes, complications have been reported. In addition, the abnormal appearance of fat cells in other tissues subsequent to lipoplasty has been reported in a small number of cases. The authors examined whether larger-volume lipoplasty, in the porcine model, resulted in disturbances in cardiac or pulmonary output levels, electrolytes, and liver chemistry analyses or alterations in organ histology. Nine adult porcine specimens were subjected to either lipoplasty (n = 6) with the superwet technique or no lipoplasty (n = 3). Using a Swan-Ganz catheter, cardiac output and pulmonary artery pressure measurements were obtained from initial placement before lipoplasty until 48 hours postoperatively. Blood analyte measurements were obtained. Upon euthanization, liver, kidney, and lung specimens were collected and tissue sections were prepared. No significant differences or trends were observed in cardiac parameters or blood analytes between control and experimental groups. Significant elevations in serum aspartate aminotransferase and alanine aminotransferase enzyme levels (p < 0.03) were observed in animals postoperatively (10 to 48 hours) subjected to lipoplasty compared with controls. Upon gross examination, the lung tissues of animals subjected to lipoplasty unexpectedly demonstrated patchy petechial hemorrhages on the pleural surface. Tissue sections revealed marked hemorrhagic congestion and evidence of pulmonary edema. Fat emboli were also identified within the pulmonary and renal systems.

The blood supply of the reverse temporalis muscle flap: anatomic study and clinical implications.

Although the reverse temporalis muscle flap has been used clinically, the exact vascular connection between the superficial and deep temporal vessels has not been clearly defined. The purpose of this study was to investigate the vascular territory of the reverse temporalis muscle supplied by the superficial temporal vessels. Six cadaver heads were studied using a colored lead oxide injection through the superficial temporal artery. The specimens were examined macroscopically and radiographically. The reverse temporalis muscle flap was then applied to a clinical case presenting with traumatic anterior skull base defect communicating with the nasal cavity. The cadaver specimens demonstrated that the superficial temporal artery formed an average 1.3 +/- 0.2 cm in width of dense vascular zone, which was located within 1.8 cm below the superior temporal line. The dense vascular network further perfused the anterior and posterior deep temporal arteries and the muscular branch of the middle temporal artery to supply the temporalis muscle. The mean perfused area of the temporalis muscle was 83 percent, ranging from 79 to 89 percent, in five cadaver heads. One cadaver revealed only 55 percent of perfused area in the absence of the muscular branch of the middle temporal artery. The consistent area without perfusion was located in the distal third of the posterior portion of the reverse temporalis muscle. In clinical cases, the reverse temporalis muscle flap was used successfully to obliterate the anterior skull base defect without evidence of muscle flap necrosis. The exact blood supply to the distal third of the posterior portion of the reverse temporalis muscle flap needs to be investigated further in vivo. Particular attention was paid to the inclusion of the muscular branch of the middle temporal artery in this flap to augment the blood supply to the temporalis muscle.