Timothy D. Santoro

Complications after microvascular breast reconstruction: experience with 1195 flaps.

Background: Reconstruction is an important adjunct to breast cancer management. This study evaluated the frequency of major and minor complications in the largest reported series of consecutive mastectomy patients treated with free tissue transfer for breast reconstruction. Methods: All patients treated with microvascular breast reconstruction at the University of California, Los Angeles, Medical Center over an 11-year period were identified using a retrospective analysis. Frequency of complications was assessed. Results: A total of 1195 breast reconstructions were performed in 952 patients. Transverse rectus abdominis musculocutaneous flaps were used in most cases (81.8 percent), whereas the superior gluteal musculocutaneous flap (10.1 percent) and other free flaps were used in the remaining patients. The overall complication rate was 27.9 percent and consisted primarily of minor complications (21.7 percent). Major complications were noted in 7.7 percent, including six total flap losses (0.5 percent). Obesity was a major predictor of complications. Smoking was not associated with increased rates of overall or microsurgical complications. Neoadjuvant chemotherapy was also an independent predictor of complications and was associated with wound-healing problems and fat necrosis. Prior abdominal surgery in transverse rectus abdominis musculocutaneous flap patients increased the risk of partial flap loss, fat necrosis, and donor-site complications. Conclusions: Microsurgical breast reconstruction is a safe and highly effective technique. Complications tend to be minor and do not affect postreconstruction adjuvant therapy. Obesity is a major predictor of flap and donor-site complications, and these patients should be appropriately counseled. Similarly, neoadjuvant preoperative chemotherapy and prior abdominal surgery increase the rates of minor complications.

Osteogenesis in calvarial defects: contribution of the dura, the pericranium, and the surrounding bone in adult versus infant animals.

Guided bone regeneration is a promising means for reconstructing bone defects in the cranium. The present study was performed to better define those factors that affect osteogenesis in the cranium. The authors studied a single animal model, investigating the contribution of the dura, the pericranium, and the adjacent calvarial bone in the process of calvarial regeneration in both mature and immature animals. Bilateral, 100-mm2, parietal calvariectomies were performed in immature (n = 16) and mature (n = 16) rabbits. Parietal defects were randomized to one of four groups depending on the differential blockade of the dura and/or the pericranium by expanded polytetrafluoroethylene membranes. Animals were humanely killed after 12 weeks, and histometric analysis was performed to quantitate the area of the original bone defect, new bone formation, and new bone density. Bone formation was quantified separately both at the periphery and in the center of the defects. Extrasite bone formation was also quantified both on the dural and on the pericranial sides of the barriers. Bone regeneration was incomplete in all groups over the 12-week study period, indicating that complete bone healing was not observed in any group. The dura was more osteogenic than the pericranium in mature and immature animals, as there was significantly more extrasite bone formed on the dural side in the double expanded polytetrafluoroethylene barrier groups. In both the dural and the double expanded polytetrafluoroethylene barrier groups, dural bone production was significantly greater in immature compared with mature animals. The dura appeared to be the source of central new bone, because dural blockade in the dural and double expanded polytetrafluoroethylene groups resulted in a significant decrease in central bone density in both mature and immature animals. Paradoxically, isolation of the pericranium in mature animals resulted in a significant reduction in total new bone area, whereas pericranial contact appeared to enhance peripheral new bone formation, with the control group having the greatest total new bone area. The present study establishes a model to quantitatively study the process of bone regeneration in calvarial defects and highlights differences in the contribution of the dura and pericranium to calvarial bone regeneration between infant and adult animals. On the basis of these findings, the authors propose that subsequent studies in which permeability of the expanded polytetrafluoroethylene membranes is altered to permit migration of osteoinductive proteins into the defect while blocking prolapse of adjacent soft tissues may help to make guided bone regeneration a realistic alternative for the repair of cranial defects.

Giant congenital nevi: A 20-year experience and an algorithm for their management

A variety of treatment options exists for the management of giant congenital nevi. Confusion over appropriate management is compounded because not all giant congenital nevi are pigmented, and malignant potential varies between different types. The present study sought to define factors in the presentation of giant congenital nevi that could provide an algorithm for their management, with respect to both the extent of resection and subsequent reconstructive options. A retrospective review of all patients who presented with a congenital nevus of 20 cm2 or greater since 1980 was performed, distinguishing among nevi involving the head and neck, the torso, and the extremities. Sixty‐one patients with giant congenital nevi were evaluated (newborn to age 16 years), of which 60 nevi in 55 patients have been operated on. Giant congenital nevi having malignant potential were pigmented nevi (53 patients) and nevus sebaceus (four patients). Those not having malignant potential were verrucous epidermal nevi (three patients) and a woolly hair nevus (one patient). Of the 60 giant congenital nevi operated on, expanded flaps were used in 25, expanded full‐thickness skin grafts were used in 10, split‐thickness or nonexpanded full‐thickness skin grafts were used in 13, and serial excision was used in 30. After 1989, operations tended to use multimodality treatment plans, with an increased use of expanded full‐thickness grafts and immediate serial tissue expansion. The use of serial excision, particularly in the extremities, also increased after 1989. Serial excision was the treatment of choice when it could be completed in two procedures or less, which occurred in more than 80 percent of cases using serial excision alone. Expanded flaps were the most common mode of reconstruction in the head and neck region and were used in 49 percent of these procedures. Serial excision was the most common form of treatment in the extremities, used in 50 percent of procedures. Tissue expansion in the extremities was infrequently used to provide an expanded flap (8 percent of procedures), whereas it was frequently used to provide expanded full‐thickness skin grafts harvested from the torso (used in 31 percent of procedures). On the basis of these data, algorithms for the extent of resection and subsequent reconstructive options for giant congenital nevi were developed. Their management should be formulated relative to pigmentation, malignant potential, and anatomic location of the respective lesions. (Plast. Reconstr. Surg. 108: 622, 2001.)

Alternative venous outflow vessels in microvascular breast reconstruction.

&NA; The lack of adequate recipient vessels often complicates microvascular breast reconstruction in patients who have previously undergone mastectomy and irradiation. In addition, significant size mismatch, particularly in the outflow veins, is an important contributor to vessel thrombosis and flap failure. The purpose of this study was to review the authors’ experience with alternative venous outflow vessels for microvascular breast reconstruction. In a retrospective analysis of 1278 microvascular breast reconstructions performed over a 10‐year period, the authors identified all patients in whom the external jugular or cephalic veins were used as the outflow vessels. Patient demographics, flap choice, the reasons for the use of alternative venous drainage vessels, and the incidence of microsurgical complications were analyzed. The external jugular was used in 23 flaps performed in procedures with 22 patients. The superior gluteal and transverse rectus abdominis musculocutaneous (TRAM) flaps were used in the majority of the cases in which the external jugular vein was used (72 percent gluteal, 20 percent TRAM flap). The need for alternative venous outflow vessels was usually due to a significant vessel size mismatch between the superior gluteal and internal mammary veins (74 percent). For three of the external jugular vein flaps (13 percent), the vein was used for salvage after the primary draining vein thrombosed, and two of three flaps in these cases were eventually salvaged. In three patients, the external jugular vein thrombosed, resulting in two flap losses, while the third was salvaged using the cephalic vein. A total of two flaps were lost in the external jugular vein group. The cephalic vein was used in 11 flaps (TRAM, 64.3 percent; superior gluteal, 35.7 percent) performed in 11 patients. In five patients (54.5 percent), the cephalic vein was used to salvage a flap after the primary draining vein thrombosed; the procedure was successful in four cases. In three patients, the cephalic vein thrombosed, resulting in two flap losses. One patient suffered a thrombosis after the cephalic vein was used to salvage a flap in which the external jugular vein was initially used, leading to flap loss, while a second patient experienced cephalic vein thrombosis on postoperative day 7 while carrying a heavy package. There was only one minor complication attributable to the harvest of the external jugular or cephalic vein (small neck hematoma that was aspirated), and the resultant scars were excellent. The external jugular and cephalic veins are important ancillary veins available for microvascular breast reconstruction. The dissection of these vessels is straightforward, and their use is well tolerated and highly successful. (Plast. Reconstr. Surg. 112: 448, 2003.)

Effects of transforming growth factor-beta and mechanical strain on osteoblast cell counts: an in vitro model for distraction osteogenesis.

Factors known to regulate bone production during distraction osteogenesis include mechanical strain on bone forming cells and up‐regulation of transforming growth factor‐&bgr; (TGF‐&bgr;) during the distraction, or strain phase of distraction osteogenesis. In the present study, an in vitro model was used to evaluate the functional effect of exogenous TGF‐&bgr;1 on mitogenesis in murine‐derived MC3T3 osteoblasts during the period of active mechanical strain. The first hypothesis to be tested was that mitogenic suppression of MC3T3 osteoblasts by TGF‐&bgr;1 is further enhanced when these cells are also subjected to mechanical strain. To test this hypothesis, MC3T3 osteoblasts were seeded on flexible and rigid membranes. These were subjected to cyclic, vacuum‐induced strain, simulating physiologic stress loads. After 24 hours, all cells were transferred to media containing TGF‐&bgr;1, and strain was continued for an additional 48 hours. The study was repeated by using two doses of TGF‐&bgr;1. This study demonstrated that final cell counts were significantly decreased in the presence of TGF‐&bgr;1 in both the nonstrained and strained groups (p < 0.0001). The final cell count in the strained group was significantly less than that in the nonstrained group (p < 0.0001) for both concentrations of TGF‐&bgr;1 tested, confirming the initial hypothesis. The second hypothesis to be tested was that alteration in the mitogenic response of MC3T3 osteoblasts after strain is not directly due to autocrine factors produced by the strained osteoblasts. To test this hypothesis, a proliferation assay was performed on nonconfluent MC3T3 osteoblasts by using conditioned media collected from strained and nonstrained osteoblasts. This study demonstrated no significant differences in cell counts after addition of conditioned media collected from strained versus nonstrained cells, confirming the latter hypothesis. The present study demonstrates the functional significance of mechanical strain on osteoblast cell counts. Furthermore, this may help to explain the temporal relationship observed during the early distraction (strain) phase of distraction osteogenesis in rodent models in which peak up‐regulation of TGF‐&bgr;1 gene expression correlates with peak suppression of osteoblast function as measured by gene expression of extracellular matrix proteins. (Plast. Reconstr. Surg. 105: 130, 2000.)

A prospective evaluation of the prevalence of submucous cleft palate in patients with isolated cleft lip versus controls

Although there is an established relationship between cleft lip and overt cleft palate, the relationship between isolated cleft lip and submucous cleft palate has not been investigated. To test the hypothesis that patients with isolated cleft lip have a greater association with submucous cleft palate, a double-armed prospective trial was designed. A study group of 25 consecutive children presenting with an isolated cleft lip, with or without extension through the alveolus but not involving the secondary palate, was compared with a control group of 25 children with no known facial clefts. Eligible patients were examined for the presence of physical criteria associated with classic submucous cleft palate, namely, (1) bifid uvula, (2) absence of the posterior nasal spine, and (3) zona pellucida. Nasoendoscopy was subsequently performed just after induction of general anesthesia, and the findings were correlated with digital palpation of the palatal muscles. Patients who did not satisfy all three physical criteria and in whom nasoendoscopy was distinctly abnormal relative to the control group were classified as having occult submucous cleft palate. Classic submucous cleft palate was found in three study group patients (12 percent), all of whom had flattening or a midline depression of the posterior palate and musculus uvulae on nasoendoscopy and palpable diastasis of the palatal muscles under general anesthesia. An additional six study group patients (24 percent) had similar nasoendoscopic criteria and palpable diastasis of the palatal muscles; they were classified as having occult submucous cleft palate. No submucous cleft palate was identified in the control group. Seventeen patients in the study group had an alveolar cleft with a 53 percent (9 of 17) prevalence of submucous cleft palate. In the present study, classic submucous cleft palate in association with isolated cleft lip was 150 to 600 times the reported prevalence in the general population. All children with an isolated cleft lip should undergo peroral examination and speech/resonance assessment no later than the age of 3 years. Any child with an isolated cleft lip with velopharyngeal inadequacy or before an adenoidectomy should be assessed by flexible nasal endoscopy to avoid missing an occult submucous cleft palate.

Long-term remodeling of vascularized and nonvascularized onlay bone grafts: a macroscopic and microscopic analysis.

The present study was performed to compare vascularized and nonvascularized onlay bone grafts to investigate the potential effect of graft-to-recipient bed orientation on long-term bone remodeling and changes in thickness and microarchitectural patterns of remodeling within the bone grafts. In two groups of 10 rabbits each, bone grafts were raised bilaterally from the supraorbital processes and placed subperiosteally on the zygomatic arch. The bone grafts were oriented parallel to the zygomatic arch on one side and perpendicular to the arch on the contralateral side. In the first group, vascularized bone grafts were transferred based on the auricularis anterior muscle, and in the second group nonvascularized bone grafts were transferred. Fluorochrome markers were injected during the last 3 months of animal survival, and animals were killed either 6 or 12 months postoperatively. The nonvascularized augmented zygoma showed no significant change in thickness 6 months after bone graft placement and a significant decrease in thickness 1 year after graft placement (p < 0.01). The vascularized augmented zygoma showed a slight but statistically significant decrease in thickness 6 months after graft placement (p < 0.003), with no significant difference relative to its initial thickness 1 year after graft placement. In animals killed 6 months after bone graft placement, both the rate of remodeling and the bone deposition rate measured during the last 3 months of survival were significantly higher in the vascularized bone grafts compared with their nonvascularized counterparts (p < 0.02). By 1 year postoperatively, there were no significant differences in thickness, mineral apposition rate, or osteon density between bone grafts oriented perpendicular and parallel to the zygomatic arch. These findings indicate that the vascularity of a bone graft has a significant effect on long-term thickness and histomorphometric parameters of bone remodeling, whereas the direction of placement of a subperiosteal graft relative to the recipient bed has minimal effect on these parameters. In vascularized bone grafts, both bone remodeling and deposition are accelerated during the initial period following graft placement. Continued bone deposition renders vascularized grafts better suited for the long-term maintenance of thickness and contour relative to nonvascularized grafts.

Free TRAM flap breast reconstruction after abdominal liposuction.

Liposuction is the most common cosmetic surgical procedure performed for women today. A large percentage of these cases involve abdominal liposuction, and more than 75 percent of these patients are younger than 50 years old.1 Concomitantly, the incidence of breast cancer is increasing, with one out of every eight women affected.2 Eighty percent of breast cancer cases are diagnosed in women older than 50.3–5 Therefore, the number of women with breast cancer who have undergone abdominal liposuction will most likely increase. Many of these women may wish to undergo autologous tissue breast reconstruction after mastectomy. The safety and success of performing a transverse rectus abdominis muscle (TRAM) flap breast reconstruction after abdominal liposuction have yet to be determined. No preoperative test has been conclusively shown to document the patency of the perforating vessels from the deep inferior epigastric system. Two case reports have documented successful TRAM flap reconstruction after abdominal liposuction. We present a series of three patients who underwent five free TRAM flaps after abdominal liposuction and describe the preoperative assessment used to help determine which patients were candidates for this procedure.