Biocompatibility of a cuprophane charcoal-based detoxification device in cirrhotic patients with hepatic encephalopathy.

Extracorporeal detoxification has been proposed to treat patients with hepatic encephalopathy (HE) not responding to standard therapy. To investigate the biocompatibility of a cuprophane charcoal-based detoxification device, a prospective, randomized, controlled study was performed. Of 41 consecutive patients with cirrhosis and HE grade II or III who did not improve with conventional treatment, 20 patients (median age, 56 years; range, 33 to 71 years; 13 men) were randomly assigned to either ongoing conventional treatment or one additional 6-hour treatment with a sorbent suspension dialysis system. Main outcome parameters were physiological function and blood parameters of biocompatibility. In the 10 patients undergoing combined conventional and sorbent suspension dialysis treatment, blood pressure remained unchanged and body temperature and heart rate increased (P: < 0.01). Platelet count decreased (medians, from 75 to 26 g/L; P: < 0.001) and international normalized ratio increased after combined treatment (2.0 to 2.2; P: < 0.001). Three patients developed bleeding complications during treatment or shortly after. Treated patients showed increases in levels of plasma elastase (104 to 586 microg/L; P: = 0.001), tumor necrosis factor-alpha (5.4 to 7.5 pg/mL; P: = 0.04), and interleukin-6 (118 to 139 pg/mL; P: = 0.04), but not interferon-gamma and E-selectin. No changes were observed in the 10 patients treated conventionally. In conclusion, despite technical refinements compared with charcoal hemoperfusion, biocompatibility of sorbent suspension dialysis is still very limited. Clinical complications were apparently caused by blood-membrane interactions and disseminated intravascular coagulation. We suggest further developments in design and appropriate strategies of anticoagulation to improve the biocompatibility of artificial liver support.

Rigid internal fixation for fractures involving tooth-bearing maxillary segments.

Fracture dislocations of the middle third of the face usually involve a complex combination of the three types of fractures initially described by LeFort. Treatment of these injuries requires a six- to eight-week period of intermaxillary fixation, unless rigid internal fixation devices (plates and screws) are used to stabilize the fractures. However, rigid fixation carries the risk of producing a malunion and serious malocclusion if not performed correctly. A review of 22 patients with complex LeFort fractures treated with rigid fixation revealed that the only absolute contraindication to its use is difficulty in interdigitating the maxillary and mandibular teeth in a passive fashion at the time of fracture reduction. Rigid internal fixation should therefore be considered as an alternative treatment for most fractures of the middle third of the face.

Motion observed across maxillary continuity defects stabilized with plates and screws.

The stability of fixation obtained with internal fixation devices (plates and screws) under functional loading of maxillary continuity defects was studied using fresh cadaver skulls. Micromotion (deformation) was recorded in the model across the level of the LeFort I osteotomies even when fixation was thought to be grossly stable. Deformation in this biologically static model proved to be mostly elastic in nature, and the amount of deformation in each skull appeared to be predictable from the average stability of all screws used in each plate. Such motion in viable bone could lead to permanent deformation due to resorption and remodeling of bone around the screws if initial overall fixation stability is tenuous. The results suggest that the term "rigid" is inappropriately used to describe plate and screw fixation of maxillary continuity defects.

Reconstruction of the pediatric maxilla and mandible.

BACKGROUND: The creation of osseous defects in the upper and lower jaws in children is an uncommon occurrence. It is therefore likely that a head and neck reconstructive surgeon will accumulate only limited experience in restoring such defects. We have reviewed 7 pediatric bone-containing microvascular free flap reconstructions in 6 patients for reconstruction of the upper or lower jaws. Three patients were available for long-term follow-up to evaluate the effect of osseous free flap reconstruction on function and growth and development of the donor site. DESIGN: Retrospective review. SETTING: Academic tertiary referral center for otolaryngology. PATIENTS AND METHODS: Six pediatric patients ranging in age from 8 to 16 years underwent 2 fibular, 4 scapular, and 1 iliac free flap procedure for restoration of 2 maxillary and 5 mandibular defects from 1992 to 1997. Three of the 6 patients were available for long-term follow-up to assess the postoperative donor site function in an effort to determine the effect of this surgery on long-term donor site morbidity and development. RESULTS: Two patients were lost to follow-up, and 1 died secondary to complications related to distant metastatic disease. Three of 6 patients were observed for 2 years 6 months, 4 years, and 4 years 2 months, respectively. Two of the 3 patients who were observed long term have undergone full dental rehabilitation and currently maintain a regular diet and deny pain with mastication or deglutition. One patient did not require dental rehabilitation. All 3 patients demonstrate gross facial symmetry and normal dental occlusion. Assessment of the fibular donor site demonstrated normal limb length and circumference. The patients denied pain or restriction to recreational activity. Scapular donor sites demonstrated normal range of motion, strength, and shoulder stability. CONCLUSIONS: Free flap reconstruction of the pediatric maxilla and mandible requires harvesting bone from actively growing donor sites. We have found no evidence of functional deficit after bone harvest from the fibular or scapular donor sites. Patients demonstrate normal growth at the donor sites, and symmetry of the mandible and maxilla is preserved.

Free-tissue transfer reconstruction of midfacial and cranio-orbito-facial defects.

OBJECTIVE: To review our results using free-tissue transfer to reconstruct midfacial and cranio-orbito-facial defects. DESIGN: Case series. SETTING: The University of Iowa Hospitals and Clinics, Iowa City. PATIENTS: Fourteen of 21 patients had defects that resulted from ablative oncologic surgery; six had severe mid-facial trauma; and one had Romberg's disease. INTERVENTIONS: Four latissimus dorsi, 11 rectus abdominis, three scapula, and four forearm free-tissue transfer flaps were used. MAIN OUTCOME MEASURES: Adequate flap separation of vital structures (intracranial contents and carotid artery) from the sinonasal or oropharyngeal cavities; restoration of palatal competence, oral diet, and speech intelligibility; maxillary dental rehabilitation; aesthetic results; complications; and the patient's return to social activities outside the home after surgery. RESULTS: The intracranial contents (six cases) or carotid artery (four cases) were protected from sinonasal or oropharyngeal contamination by the reconstructive flap in all cases in which this was required. Functional closure of the palate with the flap or a prosthesis was possible in 12 of the 13 patients with a palatal defect; seven of these 13 patients have had full maxillary dental rehabilitation. Twenty patients take an oral diet. Sixteen patients have normal or easily understood speech. Fourteen patients engage in social activities outside the home, and eight have returned to full-time employment. No vascular flap failures occurred in this series. CONCLUSIONS: The use of free-tissue transfer flaps is a safe and effective technique for repairing large midfacial and cranio-orbito-facial defects resulting from ablative oncologic surgery or trauma.

Risk factors for advanced-stage oral cavity cancer.

OBJECTIVE: To assess the association between risk factors for inadequate surveillance of oral cavity cancer and stage of disease (localized, T1, T2/N0 vs advanced, T1, T2/N1-3, T3, T4/N0 or N1-3). DESIGN: Convenience sample from a case series. SETTING: Otolaryngology clinic in a tertiary care hospital. PARTICIPANTS: Fifty-three patients with cancer of the oral cavity who were treated at The University of Iowa, Iowa City, from October 1990 through March 1994, participated in the study. Selection criteria included pathologic confirmation of squamous cell carcinoma (SCC) of the oral cavity, the capacity to retrieve data regarding tumor characteristics at initial presentation, and completion of a 30-item questionnaire by the patient. INTERVENTION: Administration of questionnaire identifying factors contributing to inadequate surveillance of cancer of the oral cavity. OUTCOME MEASUREMENTS: Advanced-stage cancer of the oral cavity was identified by the presence of large tumors (T3, T4) and cancer metastatic to the neck lymph nodes (N1, N2, N3). Comparison groups were built to determine the relationship between these two dependent variables and multiple independent variables. Descriptive statistics and tests of association were used to assess relationships. RESULTS: Two of the 53 patients performed self oral examinations specifically designed to screen for cancer prior to finding cancer of the oral cavity. Knowledge of the warning signs of cancer of the oral cavity was denied by 87%. The rate of cancer growth in the oral cavity was variable from first discovery by the patient to the time of tumor staging by otolaryngologists. The interval from discovery of the tumor to tumor staging (delay in diagnosis) was greatest for floor of the mouth cancers and shortest for those cancers located on the tongue. Thirty-seven percent of the patients younger than age 64 years were edentulous in contrast to 62% edentulism in patients older than 65 years. There was a significant, inverse relationship between time since last dental visit and late-stage disease. CONCLUSIONS: Patients with advanced-stage cancer of the oral cavity tended to be elderly, more often wore dentures, and seldom visited the dentist. Treatment of cancer of the oral cavity as localized disease, with an associated decrease in morbidity and mortality, is likely to result by targeting this population as one in need of more intense surveillance.

Osseointegrated implants: a comparative study of bone thickness in four vascularized bone flaps.

Primary and secondary reconstruction of mandibular continuity defects with vascularized bone is currently the standard of care at many institutions. The most commonly utilized donor sites for such bone flaps include the scapula, iliac crest, fibula, and radius. Recently, interest has grown in the placement of osseointegrated implants into these flaps to facilitate functional dental rehabilitation. There are no studies comparing the bone available from each of these flaps into which osseointegrated implants can be placed. In this cadaver study, the dimensions of bone available for implant placement from the iliac crest, scapula, fibula, and radius osseous flaps were measured. The iliac crest and fibula flaps had bone dimensions consistently adequate for implant placement. Bone available for the safe placement of implants into the scapula flap was found in the majority of specimens. The radius flap group had the highest number of specimens that were inadequate for implant placement. The majority of the specimens with bone inadequate for implantation were from females. Clinical implications of this study regarding flap selection are discussed.

Management of aggressive midface and orbital fibrous dysplasia.

OBJECTIVE: To discuss cosmetic and functional implications in the evaluation and treatment planning of large, aggressive midfacial fibrous dysplasias. PATIENTS AND METHODS: Eight patients (aged 2-38 years) with large fibrous dysplasias of the maxilla, zygomatic, and ethmoid bones requiring varying degrees of intervention and reconstruction were retrospectively reviewed. Patients with smaller lesions of these regions not requiring resection and reconstruction, as well those requiring sinus surgery alone were excluded from this review. RESULTS: All fibrous dysplasias in this review were monostotic, 6 originating in the maxilla, 1 in the zygoma, and 1 in the ethmoid. Five lesions (4 maxillary, 1 zygomatic) caused cosmetic deformity without functional deficits and required resection and/or contouring only with minimal reconstruction. The remaining lesions were invasive such that function of the eye and/or dentition was affected. These lesions were treated by aggressive resection and various degrees of reconstruction to optimize function. CONCLUSIONS: While fibrous dyplasia is classified as a benign process, local expansion can cause significant functional and aesthetic deformities. Each lesion should be thoroughly evaluated and, when vital structures are involved or threatened, total or subtotal resection should be considered. A variety of options should be available to the surgeon for definitive primary reconstruction.

Osseous free tissue transfer in head and neck reconstruction.

Large palatomaxillary and oromandibular defects have a dramatic impact on speech, deglutition, mastication, and cosmesis. Traditional methods of reconstruction, such as locoregional flaps, free bone grafts, alloplastic materials, and prosthetic devices, have difficulty providing meaningful aesthetic and functional reconstruction of these defects. This article discusses current concepts in the reconstruction of large composite palatomaxillary and oromandibular defects with an emphasis on the role of free tissue transfer, including the factors to be evaluated when choosing a method of reconstruction, indications for specific donor sites, and recent technical refinements.

Functional dental rehabilitation of massive palatomaxillary defects: cases requiring free tissue transfer and osseointegrated implants.

BACKGROUND: Mandibular reconstruction with functional dental rehabilitation using a free tissue transfer bone flap as the substrate for osseointegrated implant-borne or implant-retained dental prostheses is well described. Similar use of these techniques in maxillary dental rehabilitation is less frequent and has received less attention in the literature. However, in selected cases of extensive composite defects of the maxilla, free tissue transfer reconstruction of the maxillary arch and the use of implant-borne or implant-retained dental prostheses is the only satisfactory method of achieving functional dental rehabilitation. METHODS: Three cases of maxillary reconstruction and dental rehabilitation using free tissue transfer with implant-borne or implant-retained prostheses are presented. Patient selection, reconstructive technique, and the biomechanical considerations in maxillary dental rehabilitation of large palatomaxillary defects are presented. RESULTS: The patients in this report were restored to full maxillary dental functioning. One implant of 17 implants placed in free flap bone was lost due to failure of osseointegration; 94% of the implants placed are stable an average of 18 months after dental rehabilitation was complete. CONCLUSIONS: In selected patients with extensive palatomaxillary defects due to ablative surgery or trauma, the use of free tissue transfer and osseointegrated implant-borne or implant-retained dentures may be the only method possible to restore maxillary dental function. Dental rehabilitation of large maxillary defects presents a number of biomechanical challenges which must be clearly understood and overcome to achieve a long-term, functional dental rehabilitation.

Impression technique for nonosseous free-tissue transfer reconstruction after cranioorbitomaxillary resection: A clinical report.

The use of vascularized free-tissue transfers has given the head and neck surgeon the ability to offer enhanced oncologic therapy with less risk of exposing vital structures to the aerodigestive tract. Resulting free-flap tissue consistencies and contours inhibit the successful use of routine impression techniques. The technique described in this clinical report uses a previously reported procedure to obtain an accurate impression of residual palatal and free-flap structures. The significance of this technique is that it improves the tissue reproduction of surgically closed palatal defects.

Effects of implant anchorage on midface prostheses.

STATEMENT OF PROBLEM: Acquired midface defects may produce functional and psychologic impairments that adversely effects a patient's quality of life. Conventional prostheses may lack adequate retention and stability, diminishing the patient's confidence that the prosthesis will remain in place during routine activities. PURPOSE: The experience with and patient response to endosseous implants in prosthetic restoration of midface defects is presented in this study. MATERIAL AND METHODS: Five patients in age from 36 to 88 years were treated with 19 titanium endosseous root-form implants to provide retention and stability for prostheses. Patients responded to a questionnaire rating overall use, effectiveness, and satisfaction of their prosthesis, before and after the use of implants. RESULTS: All 19 implants were judged to be osseointegrated at abutment connection. Of the 17 implants used prosthetically, 14 (82%) remained osseointegrated and 3 (18%) failed. Analysis of the questionnaire tends to indicate an improvement of the quality of life for the patients with an implant-retained prosthesis.

Associations between selected demographic parameters and dental status: potential implications for orodental rehabilitation.

PURPOSE: This pilot study evaluated potential relationships between dental status and various sociodemographic variables in the age group segment of the United States population at greatest risk for the disruption of dental function due to treatment of an oral cavity cancer. METHODS: The Dental Health Supplement of the 1989 National Health Interview Survey was used to evaluate the self-reported status of natural dentition and prior dental rehabilitation among the population of persons 45 years or older. RESULTS: Sociodemographic variables, which showed a significant association with status of natural dentition, were level of income and occupation at lower income levels (p < 0.05). Increased levels of prior dental rehabilitation were significantly associated with lower age, female gender, increased level of income, and occupation (p < 0.05). Occupations that required social interaction had the highest levels of both status of natural dentition and prior dental rehabilitation (p < 0.05). CONCLUSIONS: Overall dental status after treatment of oral cancer may be related to the occupational status of many persons. Sociodemographic factors that influence the dental rehabilitation needs of individual patients after treatment of an oral cancer should be considered in policy decisions affecting accessibility of dental rehabilitative care. A follow-up, survey study that would further define the identified relationships between a person's demographic status and dental rehabilitation needs is recommended.

Pectoralis major myofascial flap: a valuable tool in contemporary head and neck reconstruction.

BACKGROUND: The pectoralis major myofascial (PMMF) unit is rapidly mobilized, reliable, and extremely useful in a number of clinical situations calling for vascularized soft-tissue coverage in the head and neck. Although free-tissue transfer has emerged as the preferred method of reconstruction for a large variety of defects in the head and neck, the pectoralis major muscle should be considered when vascularized soft-tissue coverage is required in this area. METHODS: A retrospective chart review of 24 PMMF flaps performed at the University of Iowa Hospitals and Clinics between January 1, 1991, and May 1, 1996, was undertaken. Outcomes were evaluated relative to accomplishing the established preoperative surgical goals. RESULTS: Utilization of the PMMF flap was grouped according to four primary indications: (1) protection of threatened great vessels or free flap vascular pedicles in situations of wound breakdown due to fistula or infection (7 cases); (2) vascularized soft-tissue coverage of great vessels or free-flap vascular pedicles and prevention of potential wound breakdown in surgical defects in which compromised healing was anticipated (7 cases); (3) closure of small pharyngeal defects (2 cases); or (4) vascularized coverage of the mandible following debridement for osteoradionecrosis (8 cases). The PMMF flap was 100% successful when the surgical goal was to protect exposed vascular structures and promote wound healing in the presence of fistula or infection. The PMMF flap was 100% successful in the protection of vascular structures and prevention of wound breakdown in cases where compromised wound healing was anticipated. The PMMF flap provided closure, and a vascularized surface for mucosalization, when used to primarily reconstruct small pharyngeal defects. The PMMF flap provided definitive closure in 5 of 8 (62.5%) cases of osteoradionecrosis of the mandible when it was used to invest the remaining mandibular bone. Three of 8 cases (37.5%) required further surgical management and were considered failures. An acceptable cosmetic outcome was obtained in women undergoing this procedure by using an inframammary incision. The preoperative goal of the PMMF flap procedure was met in 21 of 24 (87.5%) cases. There was a major complication rate of 12.5% as well as a minor complication rate of 12.5%. CONCLUSION: In cases requiring the protection of vital vascular structures from infection, salivary secretions or skin flap breakdown, the PMMF flap should be considered. The PMMF flap is an excellent reconstructive option in selected clinical situations, where vascularized soft-tissue coverage is required in the head and neck.

Titanium osseointegrated implants combined with hyperbaric oxygen therapy in previously irradiated mandibles.

STATEMENT OF PROBLEM: Treatment for head and neck malignancies commonly involves radiation therapy. As a result of this therapy the vascular supply to irradiated structures is altered and results in decreased tissue perfusion. In addition to vascular changes, bony structures undergo a reduction in osteoblastic and osteoclastic activity. These tissue alterations, especially in the mandible, enhance the risk of osteoradionecrosis. To avoid this occurrence, many patients who have undergone radiation therapy do not receive elective preprosthetic surgeries, including implant therapy. PURPOSE OF STUDY AND METHODS: This report presents the preliminary results of placing 18 titanium screw implants into previously irradiated mandibles in conjunction with hyperbaric oxygen therapy. RESULTS: Of the 18 implants placed, 17 (94%) were judged to be osseointegrated at the abutment connection. One implant did not receive an abutment and was "put to sleep." The remaining 16 (88%) were used for prosthetic rehabilitation. CONCLUSION: The use of implants in irradiated tissues may provide a means of enhancing prosthetic rehabilitation while reducing the risk of tissue trauma that may develop into osteoradionecrosis.