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Biomedical subjects

J P Anthony

Publications and source records attributed to J P Anthony.

At least 19 recordsLinked to original sources
PubMed2001

Mixed allogeneic chimerism as a reliable model for composite tissue allograft tolerance induction across major and minor histocompatibility barriers.

BACKGROUND: Although prolonged composite tissue allograft (CTA) survival is achievable in animals using immunosuppressive drugs, long-term immunosuppression of CTAs in the clinical setting may be unacceptable for most patients. The purpose of this study was to develop a model for reliable CTA tolerance induction in the adult rat across a major MHC mismatch without the need for long-term immunosuppression. METHODS: Mixed allogeneic chimeras were prepared by using rat strains with strong MHC incompatibility [WF (RT1Au), ACI (RT1Aa)] WF + ACI-->WF, n=23. The bone marrow (BM) of recipient animals was pretreated with low-dose irradiation (500-700 cGy), followed by reconstitution with a mixture of T cell-depleted syngeneic (WF) and allogeneic (ACI) cells. Additionally, the recipient animals received a single dose of anti-lymphocyte serum (10 mg) 5 days before bone marrow transplantation (BMT) and tacrolimus (1 mg/kg/day) from the day before BMT to 10 days post-BMT. Hindlimb transplants were performed 12 months after BMT. Five animals received a limb allograft irradiated (1000 cGy) just before transplantation. Rat chimeras were characterized (percentage of donor cells present within the bloodstream) by flow cytometry at 3 and 12 months after BM reconstitution and after hindlimb transplantation. RESULTS: Peripheral blood lymphocyte chimerism (WF/ACI) remained stable >12 months after BM reconstitution in 18/23 animals. Multi-lineage chimerism of both lymphoid and myeloid lineages was present, suggesting that engraftment of the pluripotent rat stem cell had occurred. In animals with donor chimerism >60% (n=18) no sign of limb rejection was present for the duration of the study. All animals with chimerism <20% (n=5) developed moderate signs of rejection clinically and histologically. Gross motor and sensory reinnervation (weight bearing, toe spread) developed at >60 days in 14/21 rats. Postoperative flow cytometry studies demonstrated stable chimerism in all animals studied (n=10). Five out of five animals with irradiated limb transplants showed no sign of GVHD at >100 days. CONCLUSIONS: Stable mixed allogeneic chimerism can be achieved in a rat hindlimb model of composite tissue allotransplantation. Hindlimb allografts to mixed allogeneic chimeras exhibit prolonged, rejection-free survival. Partial functional return should be expected. The BM transplanted as part of the hindlimb allograft plays a role in the etiology of GVHD. Manipulating that BM before transplantation may influence the incidence of GVHD. This represents the first reliable rat hindlimb model demonstrating rejection-free CTA survival in an adult animal across a major MHC mismatch without the long-term need for immunosuppressive agents.

Animals↗
PubMed2001

Immunological studies of chronic ocular toxoplasmosis: up-regulation of major histocompatibility complex class I and transforming growth factor beta and a protective role for interleukin-6.

A murine model was used to characterize the local immune and inflammatory response during ocular toxoplasmosis. Major histocompatibility complex (MHC) class I, normally expressed at low levels in immune-privileged sites such as the eye, was up-regulated during infection as determined by competitive reverse transcriptase (RT)-PCR and immunocytochemistry for both beta2-microglobulin and the MHC class I heavy chain. However, the eyes of chronically infected mice also had increased levels of mRNA transcripts for transforming growth factor beta, a cytokine associated with immune privilege and constitutively expressed in normal eyes. Transcripts for a number of inflammatory mediators, including interleukin-6 (IL-6), were increased during chronic infection. The role of IL-6 was further investigated by comparing disease progression and the development of the local immune response in wild-type (WT) and IL-6-deficient mice (IL-6(-/-) mice). Following infection, IL-6(-/-) mice developed more severe inflammation in the retina and vitreous humor compared with WT mice. This increased severity of disease was associated with reduced ocular IL-1alpha and increased tumor necrosis factor alpha mRNA production compared with WT mice. Moreover, the increased severity of disease in IL-6(-/-) mice correlated with increased eye parasite burden as determined by RT-PCR for the Toxoplasma gondii bradyzoite-specific LDH2 gene. These results demonstrate alterations to components of immune privilege as a result of ocular toxoplasmosis and a role for IL-6 in controlling parasite numbers and inflammation in the eye.

Animals↗
PubMed2000

Antidepressant-induced regulation of 5-HT(1b) mRNA in rat dorsal raphe nucleus reverses rapidly after drug discontinuation.

Serotonin release from dorsal raphe projections in the forebrain is regulated by terminal 5-HT(1B) autoreceptors; dysregulation of these receptors may be involved in the pathophysiology of clinical depression. Using in situ hybridization, we have previously reported that fluoxetine reduces 5-HT(1B) mRNA in rat dorsal raphe nucleus (DRN) in a time-dependent and reversible manner. In this study we examined longer term treatment (8 weeks) with several different serotonin-selective reuptake inhibitors (SSRIs) or a tricyclic antidepressant on 5-HT(1B) mRNA regulation in DRN and hippocampus, and evaluated the stability of these drugs' effects after drug discontinuation. Fluoxetine (5 mg/kg/d), paroxetine (5 mg/kg/d), sertraline (10 mg/kg/d) or nortriptyline (10 mg/kg/d) was administered to rats via subcutaneous osmotic minipumps. Paroxetine and fluoxetine reduced DRN 5-HT(1B) mRNA by 36% and 27%, respectively whereas sertraline had a no significant effect. After 3-14 days of drug washout, DRN 5-HT(1B) mRNA levels in SSRI treated rats were no longer different from control. 5-HT(1B) mRNA levels in hippocampus were not affected by SSRI drugs at any timepoint. Nortriptyline had no significant effect on 5-HT(1B) mRNA in either DRN or hippocampus. These results confirm that SSRI antidepressants reduce presynaptic 5-HT(1B) mRNA selectively, and that this effect is maintained for at least 8 weeks of antidepressant treatment but reverses rapidly after discontinuation. Furthermore, it is possible that washout after chronic antidepressant treatment, that is routinely used in functional assays of autoreceptor action in animal models, may lead to more rapid reversal of biological effects than has previously been thought.

Animals↗
PubMed2000

Current national health insurance coverage policies for breast and ovarian cancer prophylactic surgery.

BACKGROUND: The efficacy of prophylactic mastectomy and oophorectomy in reducing breast and ovarian carcinoma has recently been reported in high-risk women. Because cost has become central to medical decision-making, this study was designed to evaluate currently existing coverage policies for these procedures. METHODS: A confidential detailed cross-sectional nationwide survey of 481 medical directors from the American Association of Health Plans, Medicare, and Medicaid was conducted. RESULTS: Of the 150 respondents, 65% (n = 97) had 100,000 or more enrolled members and 35% (n = 53) had fewer than 100,000 enrolled members. Only 44% of private plans have specific policies for coverage of prophylactic mastectomy for a strong family history of breast cancer and 38% of plans for a BRCA mutation. Only 20% of total responding plans had a policy for coverage of prophylactic oophorectomy under any clinical circumstance. Governmental carriers were significantly less likely to have any policy for prophylactic surgery (range, 2%-12%) compared with nongovernmental plans (range, 24%-44%; P < .001). No significant regional differences for coverage policies were identified (P > .05). CONCLUSIONS: Significant variations currently exist for health insurance coverage of prophylactic mastectomy and oophorectomy. As genetic testing becomes widespread, more uniform policies should be established to enable appropriate high-risk candidates equal access and coverage for these procedures.

BRCA2 Protein↗
PubMed2000

Complex abdominal wall reconstruction: a comparison of flap and mesh closure.

OBJECTIVE: To analyze a series of patients treated for recurrent or chronic abdominal wall hernias and determine a treatment protocol for defect reconstruction. SUMMARY BACKGROUND DATA: Complex or recurrent abdominal wall defects may be the result of a failed prior attempt at closure, trauma, infection, radiation necrosis, or tumor resection. The use of prosthetic mesh as a fascial substitute or reinforcement has been widely reported. In wounds with unstable soft tissue coverage, however, the use of prosthetic mesh poses an increased risk for extrusion or infection, and vascularized autogenous tissue may be required to achieve herniorrhaphy and stable coverage. METHODS: Patients undergoing abdominal wall reconstruction for 106 recurrent or complex defects (104 patients) were retrospectively analyzed. For each patient, hernia etiology, size and location, average time present, technique of reconstruction, and postoperative results, including recurrence and complication rates, were reviewed. Patients were divided into two groups based on defect components: Type I defects with intact or stable skin coverage over hernia defect, and Type II defects with unstable or absent skin coverage over hernia defect. The defects were also assigned to one of the following zones based on primary defect location to assist in the selection and evaluation of their treatment: Zone 1A, upper midline; Zone IB, lower midline; Zone 2, upper quadrant; Zone 3, lower quadrant. RESULTS: A majority of the defects (68%) were incisional hernias. Of 50 Type I defects, 10 (20%) were repaired directly, 28 (56%) were repaired with mesh only, and 12 (24%) required flap reconstruction. For the 56 Type II defects reconstructed, flaps were used in the majority of patients (n = 48; 80%). The overall complication and recurrence rates for the series were 29% and 8%, respectively. CONCLUSIONS: For Type I hernias with stable skin coverage, intraperitoneal placement of Prolene mesh is preferred, and has not been associated with visceral complications or failure of hernia repair. For Type II defects, the use of flaps is advisable, with tensor fascia lata representing the flap of choice, particularly in the lower abdomen. Rectus advancement procedures may be used for well-selected midline defects of either type. The concept of tissue expansion to increase both the fascial dimensions of the flap and zones safely reached by flap transposition is introduced. Overall failure is often is due to primary closure under tension, extraperitoneal placement of mesh, flap use for inappropriate zone, or technical error in flap use. With use of the proposed algorithm based on defect analysis and location, abdominal wall reconstruction has been achieved in 92% of patients with complex abdominal defects.

Abdominal Muscles↗
PubMed1999

Vascularized bone flaps versus nonvascularized bone grafts for mandibular reconstruction: an outcome analysis of primary bony union and endosseous implant success.

BACKGROUND: Functional restoration following resection or traumatic injury to the mandible depends on the reliability of the bony reconstruction to heal primarily and support endosseous implants. Although vascularized bone flaps (VBF) and nonvascularized bone grafts (NVBG) are both widely used to reconstruct the mandible, indications for each remain ill-defined. The purpose of this study was to compare bone graft/flap healing and success of implant placement in patients reconstructed with VBF versus NVBG. METHODS: Over the past 10 years, 75 consecutive mandibular reconstructions were performed (26 free bone grafts, 49 vascularized bone flaps). Etiology of the defect, history of irradiation, bone defect size, number of operations, graft/flap success, and dental implant success rates were determined and compared. Bone graft/flap success was defined as complete bony union. Implant success was defined as complete osseointegration. Mean follow-up was 3 years. RESULTS: Free flaps were used primarily for malignant disease (78%, 38/49). Bone grafts were used primarily for benign disease (88%, 23/26). History of prior irradiation: 11% (3/26) NVBG versus 45% (22/49) VBF. Length of bony defect (mean): 8.1 cm NVBG versus 9.4 cm VBF. Successful bony union, any size defect: 69% (18/26) NVBG versus 96% (47/49) VBF (p < .0005); lateral defects only: 75% (15/20) NVBG versus 100% (17/17) VBF (p < .05). Number of operations to achieve bony union (mean), any size defect: 2.3 NVBG versus 1.1 VBF (p < .001); lateral defects only: 1.9 NVBG versus 1.0 VBF (p < .005). Twenty-two patients (29%) had a total of 104 endosseous implants placed (NVBG: 8 patients, 33 implants; VBF: 14 patients, 71 implants). Immediate implants placed: 0/33 NVBG versus 54% (38/71) VBF. Overall implant success: 82% (27/33) NVBG versus 99% (70/71) VBF (p < .0001). Implant success in VBF patients with a history of RT: 100% (15/15). CONCLUSIONS: Despite the fact that patients reconstructed with VBFs were older, had larger defects, and were treated primarily for malignant disease and therefore had a higher incidence of irradiation to the affected mandible than in patients treated with NVBGs, the incidence of bony union was higher, requiring fewer operations to achieve union, and the implant success rate was significantly greater than for NVBG patients. Results were similar when considering lateral defects only. Based on these results, VBFs are indicated in most cases of mandibular reconstruction; NVBGs are effective for short bone defects (<5-6 cm), in nonirradiated tissue, and/or in patients determined to be too medically compromised to tolerate the additional operative time required for a free-flap reconstruction.

Adolescent↗
PubMed1998

The latissimus dorsi bladder myoplasty to assist detrusor function.

The objective of this study was to evaluate whether an innervated skeletal muscle might augment detrusor function. In four dogs we performed the latissimus dorsi myoplasty, a transfer of the latissimus muscle as an innervated free flap wrapped around the bladder. Stimulation of the latissimus dorsi free flap initially achieved an average bladder pressure of 45.8 +/- 8.41 cm H2O, sufficient for partial evacuation. After 4 months the muscle generated a maximal pressure of 82 cm H2O, resulting in an evacuation of 27.7%. For selected patients, the latissimus dorsi bladder myoplasty may provide an alternative to intermittent catheterization in the future.

Animals↗
PubMed1998

Donor-specific tolerance induction in composite tissue allografts.

BACKGROUND: Although prolonged composite tissue allograft (CTA) survival is achievable in animals using immunosuppressive drugs, long-term immunosuppression of CTAs in the clinical setting would be unacceptable for most patients. The purpose of this study was to develop a model for reliable CTA tolerance induction in the adult rat across a strongly antigenic MHC mismatch without the need for long-term immunosuppression. METHODS: Chimeras were prepared using rat strains with strong MHC incompatibility [WF (RT1Au) + ACI (RT1Aa) --> WF, n = 13]. Syngeneic (WF) and allogeneic (ACI) bone marrow (BM) was harvested and T-cell depleted. Following confirmation of T-cell depletion by flow cytometry, a mixture of T-cell depleted syngeneic and allogeneic BM was injected into the recipient animals (all recipients pretreated with low-dose irradiation, 500 to 700 cGy). In addition, the recipient animals received a single dose of ALS (10 mg) 5 days prior to bone marrow transplantation (BMT) and tacrolimus (1 mg/kg/day) from the day prior to BMT to 10 days postoperatively. Rat chimeras were characterized by flow cytometry at 3 and 12 months after BM reconstitution and following hindlimb transplantation. RESULTS: Peripheral blood lymphocyte chimerism (WF/ACI) remained stable >12 months after BM reconstitution in 10 of 13 animals. Multilineage chimerism of both lymphoid and myeloid lineages was present, suggesting that engraftment of the pluripotent rat stem cell had occurred. In animals with donor chimerism >60%, there was no sign of limb rejection for the duration of the study. All animals with chimerism <20% developed moderate signs of rejection clinically and histologically. Gross motor and sensory reinnervation (weight bearing, toe spread) occurred at >60 days in 6 of 9 rats. Postoperative flow cytometry studies demonstrated stable chimerism in all animals studied (n = 7). CONCLUSIONS: Stable mixed allogeneic chimerism can be achieved in a rat hindlimb model of composite tissue allotransplantation. Hindlimb allografts to mixed allogeneic chimeras exhibit prolonged, rejection-free survival. This represents the first reliable model demonstrating rejection-free CTA survival in an adult animal without the long-term use of immunosuppressive agents across a strongly antigenic MHC mismatch.

Animals↗
PubMed1997

Flap selection as a determinant of success in pressure sore coverage.

OBJECTIVE: To establish a treatment algorithm for the long-term surgical management of pressure sores. DESIGN: Retrospective case series. SETTING: University-based teaching hospital. PATIENTS: From March 1979 to July 1995, 280 unselected pressure sore reconstructions (113 ischial, 94 sacral, and 73 trochanteric sores) were performed in 201 patients (130 men and 71 women; age range, 16-90 years; mean, 50 years). Of the patients, 90% had severe spinal cord injuries (paraplegia or quadriplegia). Forty-one percent of the wounds were chronic (present longer than 3 months). MAIN OUTCOME MEASURES: Length of stay, postoperative morbidity and mortality, and flap success (defined as a completely healed wound). RESULTS: Overall, 89% of the flaps healed primarily (ischium, 83% [94/113]; sacrum, 91% [86/94]; trochanter, 93% [68/73]). Three fourths of cases were treated in a single stage (debridement and reconstruction). The inferior gluteus maximus island flap (ischium) (94% [32/ 34]), the V-Y gluteus maximus advancement flap (sacrum) (97% [36/37]), and the tensor fascia lata flap (trochanter) (95% [42/44]) had the highest success rates. Flap success was not significantly affected by the size of the pressure sore or the number of previous flaps used. Postoperative hospital stays averaged 20 days. The overall complication rate was 28%, most commonly from a slight wound edge dehiscence. CONCLUSIONS: Flap selection and the appropriate short- and long-term sequence of flap use significantly improve success rates for pressure sore coverage. Reconstruction can be reliably performed in a single stage with a relatively short hospitalization.

Adolescent↗
PubMed1997

Reconstruction of partial laryngopharyngectomy defects.

As our contributors to this section have pointed out, there are at present two main methods of reconstructing defects of the pharynx and cervical esophagus: free jejunal transfer (FJT) and tubed radial forearm flap. The advantage of the FJT is that it is a tube, thus limiting the enteric suture lines to proximal and distal. The radial forearm flap requires not only the proximal and distal suture lines but a long longitudinal suture line to create the tube. This increase the possibility for fistula formation. The controversy surrounding this case concerns what to do with a remaining mucosal strip after a subtotal laryngectomy. Traditional reconstructive principles would dictate that normal tissue should not be sacrificed, but some would argue that the remaining mucosa should be sacrificed to allow for use of a FJT. The other alternative would be use of a radical forearm skin flap tubed to 270 degrees. At the University of Texas M. D. Anderson Cancer Center, we preferentially use the FJT for almost all defects and would probably have sacrificed the remaining mucosal strip in this particular case. We have used skin flaps to patch pharyngeal defects and prevent stricture in a number of cases. This is usually done however when the remaining pharyngeal mucosa approaches 50% or greater. Although we do not routinely use the tubed radial forearm flap because of the increased rate of fistula formation, there are some definite indications for its use. The first important indication is in patients in whom speech rehabilitation is desired or indicated. The skin flap provides a stiffer resonating chamber for the speech production and does not have the peristalsis or the mucus production associated with the jejunal flap. Another indication for use of radial forearm flap would be when there is a contraindication to celiotomy, ie, patients with hepatic cirrhosis and associated ascites or other abdominal conditions precluding abdominal exploration. In this situation, avoiding an intra-abdominal procedure would limit operative morbidity. In conclusion, one should use whichever procedure obtains a healed wound and re-establishes continuity of the upper gastrointestinal tract. In our hands, retention of the remaining mucosal segment would not be critical in this particular case and in fact would present a hindrance to use of the FJT.

Carcinoma, Squamous Cell↗
PubMed1997

Ischial pressure sore coverage: a rationale for flap selection.

The role of wound debridement and flap coverage in treating pressure sores is clearly established. However, criteria and supportive clinical data for specific flap selection and the sequence of flaps for coverage of the ischium remain ill-defined. From 1979-1995, 114 consecutive patients underwent flap coverage of 139 ischial pressure sores. Preoperative risk factors, prior flap history, defect size, flap success, complication rates, and the length of hospitalization were retrospectively evaluated and compared for 112 flaps in 87 patients. Flap success was defined as a completely healed wound. Average follow-up was 10 months (range: 1 month-9 years). Overall, 83% (93/112) of the flaps healed. In the majority of cases (75%, 84/112), wound debridement and flap reconstruction was achieved in a single stage. However, there were significant differences in the healing rates among the various flaps used. The inferior gluteus maximus island flap and the inferior gluteal thigh flap had the highest success rates, 94% (32/34) and 93% (25/27), respectively, while the V-Y hamstring flap and the tensor fascia lata flap had the poorest healing rates, 58% (7/12) and 50% (6/12), respectively. Flap success was not significantly affected by the age of the patient or the prior number of flaps used and preoperative risk factors were equally distributed across all types of flaps. The overall complication rate was 37% (41/112), most commonly from a slight wound edge dehiscence (n = 16) that healed with local wound care within one month postoperatively. Results of this study show that proper flap selection and the appropriate sequence of flap use significantly improve success rates for ischial pressure sore coverage in both the short- and long-term. Based upon flap reliability (successful healing rates), reusability, and the need to preserve as many future flap options as possible, a rationale for flap selection is presented which can be individualized to any patient.

Adolescent↗
PubMed1997

A comparison of vascularized and nonvascularized bone grafts for reconstruction of mandibular continuity defects.

PURPOSE: This study compared vascularized and nonvascularized bone grafts for the reconstruction of segmental defects of the mandible. PATIENTS AND METHODS: The results in 39 patients having vascularized bone grafts (38 fibulas and one iliac crest) and 29 patients having nonvascularized bone grafts (26 iliac crest [22 corticocancellous block grafts, four cancellous bone grafts in a tray] and three rib grafts) for segmental mandibular reconstruction were evaluated in terms of overall success rate, total number of surgeries performed, total blood loss, total number of hospital days, and total number of hours in the operating room. RESULTS: Of 39 vascularized bone grafts, two failed (95% success rate), whereas of 29 nonvascularized bone grafts, seven failed (76% success rate). Failure for the nonvascularized bone grafts was closely correlated to the length of the defect. Nonvascularized bone graft patients underwent an average of one more surgical procedure for total reconstruction than vascularized bone graft patients, including osseointegrated implants. However, vascularized bone graft patients spent a mean of over 14 additional days in the hospital for all of their reconstructive procedures and an additional 3 hours in the operating room as compared with nonvascularized bone graft patients. Blood loss was similar in both groups (1,100 mL). Only 20% to 24% of patients in each treatment group have completed reconstruction to include osseointegrated implants. CONCLUSIONS: The success rate for vascularized bone grafting is high and is the treatment of choice when primary reconstruction is required, when the patient has been previously irradiated, or when simultaneous replacement of soft tissue is required. Vascularized bone grafts are also the treatment of choice for mandibular replacements over 9 cm in length. Nonvascularized bone grafts create a better contour and bone volume for facial esthetics and subsequent implant insertion, and may be the treatment of choice for secondary reconstruction of defects less than 9 cm in length.

Adolescent↗
PubMed1997

The free fibula bone graft for salvaging failed mandibular reconstructions.

PURPOSE: The purpose of this study was to determine the efficacy of vascularized free fibula bone grafts for mandibular salvage reconstruction. PATIENTS AND METHODS: Seven patients had fibula grafts after failed attempts at mandibular reconstruction. The prior attempts involved 20 operative procedures. Four of the seven patients (57%) had a history of radiation to the affected mandible. Bony defects averaged 10.2 cm (range, 4.5 to 24 cm), and the associated soft tissue defects averaged 6 x 12 cm. Average follow-up was 16 months. Cosmetic (facial symmetry) and functional (speech quality, oral continence, deglutition, donor site morbidity, dental rehabilitation) results were evaluated by questionnaire and clinical examinations. RESULTS: Soft tissue coverage and mandibular restoration were successful in all patients, and flap survival was 100%. Five of the seven patients (70%) achieved good or excellent functional results, and five of seven (70%) achieved good or excellent esthetic results. Complications were minimal, and the average hospital stay was 14 days. CONCLUSIONS: When the initial attempt at mandibular reconstruction is unsuccessful, mandibular function and esthetics can be salvaged with reliable vascularized soft tissue and bone flaps. As long as appropriate flap options are considered and the patient is medically stable, successful mandibular reconstruction should be achievable despite the number or cause of prior failed attempts.

Adult↗
PubMed1997

Lymphatic regeneration following microvascular limb replantation: a qualitative and quantitative animal study.

Lymphatic regeneration following unilateral hindlimb autotransplantation was studied in 14 Lewis rats using Technetium-99 radiolabeled sulfur colloid (TC-99) lymphoscintigraphy and compared to the lymphatic pattern exhibited in four unoperated control rats. Control animals demonstrate a reproducible flow of lymph along the deep lymphatic system from the foot, draining into the ipsilateral inguinal nodes, and then up to the para-aortic nodes. Following replantation, lymphatic outflow from the replanted limb begins to occur within 3 to 6 days, reaching normal lymphatic clearance within 12 days. However, the pattern of lymphatic flow is ill-defined, relying on multiple small channels of the superficial lymphatic system. In contrast to controls, at 3 hr post TC-99 injection, lymphatic drainage in replanted rats is via the inguinal and axillary nodal regions bilaterally. This abnormal pattern persisted in the replanted animals for the duration of this study, 160 days. It is evident that lymphatic regeneration in this animal model is associated with a rapid return to normal levels of lymphatic clearance via collateral channels within the subcutaneous tissue. The rapidity with which lymphatic drainage is restored, and its localization within the subcutaneous tissue, can explain why replanted tissues and microvascular free flaps seldom develop lymphedema. In addition, the rat hindlimb replantation model may prove useful for studies of the general mechanisms and specific factors responsible for lymphangiogenesis.

Animals↗
PubMed1997

Fibular free flap reconstruction of the "true" lateral mandibular defect.

The purpose of this study was to determine the role of the fibular free flap in reconstructing lateral segmental defects of the mandible. Over the past 5 1/2 years, 17 consecutive patients underwent reconstruction of their lateral mandible with the fibular free flap. Patients included 12 men and 5 women, the mean age was 54 years (range, 29-76 years), and the mean length of the mandibular defect was 6.3 cm (range, 2.5-9 cm). The majority of patients with tumors (54%) were treated for recurrence and 92% received radiation to the operative field. The mean operative time to perform the microsurgery and bone plating was 4 hours. Postoperative morbidity occurred in 3 patients (18%) (plate fracture, malocclusion, orocutaneous fistula). Five patients (29%) required leg donor site skin grafting. Donor site morbidity included a minor cellulitis, a transient neuropraxia, and one case of leg swelling. None required additional surgery for donor complications. Thus far, 71% of the patients have received dental rehabilitation and 35% had osseointegrated implants placed in their bone flap. Eighty-two percent of the patients achieved both good or excellent aesthetic and functional results. Sixteen patients (94%) tolerate at least a soft diet and 65% are on a regular diet. Five patients developed tumor recurrence an average of 9 months postoperatively with a mean survival of 21 months. This study demonstrates that the fibular free flap is highly reliable for reconstructing the lateral mandible in a single stage, with low overall morbidity, and provides for excellent dental and speech rehabilitation. For most patients, the fibular free flap should be considered for lateral mandibular reconstruction even in those patients with a limited life expectancy.

Adult↗
PubMed1997

Reconstruction of complex midfacial defects.

Modern treatment of complex midfacial defects has evolved over the past 5 years, primarily with the advent of reliable vascularized bone flaps and osseointegrated implants. To determine the effectiveness of these advances, 26 consecutive patients with complex midfacial defects treated from 1991 through 1995 with immediate muscle-flap coverage were evaluated. The etiology of the defect included neoplasm (n = 23) and trauma (n = 3). Seventy-eight percent of the patients received adjuvant radiation therapy. Follow-up ranged from 3 months to 4 years, with a mean of 18 months. Twenty-three patients (88 percent) were reconstructed with a single major procedure. All patients had free-flap reconstruction, and 100 percent of the flaps survived. Late tumor recurrence was seen in 5 of 23 patients (22 percent) and was detected promptly. Aesthetic and functional results were rated good or excellent in 77 and 88 percent of the patients, respectively, as determined by patient questionnaires and physical examinations. Fourteen of 18 patients (78 percent) undergoing partial or complete alveolar ridge resection received dental rehabilitation, 43 percent of whom received osseointegrated implants into either a bone flap or remaining native bone. Osseointegrated implants were inset during the initial reconstruction 50 percent of the time. A treatment algorithm for free-flap selection based on the size of the defect and the bony requirement for reconstruction is presented. Bony restoration is only required in those areas where osseointegrated implants need to be placed. In such cases, the fibula osteocutaneous free flap is the flap of choice. Otherwise, soft-tissue flaps are selected based on wound size. Immediate free-flap coverage provides effective, single-stage treatment, both aesthetically and functionally, for complex midfacial defects.

Adolescent↗