Functional evaluation following microvascular oromandibular reconstruction of the oral cancer patient: a comparative study of reconstructed and nonreconstructed patients

Over the past decade, the use of free flap transfers in head and neck surgery has led to remarkable advances in the reliability and the ultimate results of oromandibular reconstruction. Stable and retentive dental restorations have been achieved using enosseous implants placed directly into the vascularized bone flaps. However, the functional assessment of patients who underwent primary mandibular reconstruction with these techniques has not been previously reported. A group of 10 reconstructed and 10 nonreconstructed segmental hemimandibulectomy patients were compared using a battery of tests to assess their overall well-being, cosmesis, deglutition, oral competence, speech, length of hospitalization, and dental rehabilitation. In addition, objective measures of the masticatory apparatus (interincisal opening, bite force, chewing performance, and chewing stroke) were used to compare these two groups as well as normal healthy subjects and edentulous patients restored with conventional and implant-borne dentures. The results show a clear advantage for the reconstructed patients in almost all categories. Persistent problems and future directions in oromandibular reconstruction are discussed.

The rectus abdominis free flap in head and neck reconstruction

The rectus abdominis musculocutaneous free flap, based on the deep inferior epigastric artery and vein, has been used widely in reconstruction of the breast and extremities. The number of reports on its applications in the head and neck is limited. The rectus abdominis free flap is one of the most versatile soft-tissue flaps. The deep inferior epigastric artery and vein are long, large-diameter vessels that are ideal for microvascular anastomoses. The area of skin that can be transferred is probably the largest of all flaps presently in use. The versatility of this donor site is due to the ability to transfer large areas of skin with varying thicknesses and varying amounts of underlying muscle. We have successfully used this flap in 15 consecutive patients to reconstruct defects of the neck, face, mouth, pharynx, skull base, and scalp. No major complications involving either the recipient or donor sites occurred. The literature on the use of the rectus abdominis flap in head and neck reconstruction is reviewed in detail. The advantages and disadvantages of this soft-tissue free flap are thoroughly discussed in an effort to better define its proper place among the reconstructive options available to the head and neck surgeon.

Oromandibular reconstruction using microvascular composite free flaps. Report of 71 cases and a new classification scheme for bony, soft-tissue, and neurologic defects

We describe 71 cases of oromandibular reconstruction using microvascular composite free flaps. There was an overall flap success rate of 94%, while 97% of the patients in this series had their mandibles reconstructed with free vascularized bone flaps. Fifteen patients were rehabilitated with implant-borne dental prostheses. Primary repair of discontinuity defects of the inferior-alveolar nerve using a variety of nerve grafts was performed in 16 patients. A new classification scheme for composite defects of the oral cavity involving bone, soft tissue, and neurologic defects is proposed and applied in the description of each of the patients in this series.

Latissimus dorsi musculocutaneous flap for elbow extension

The latissimus dorsi mycocutaneous flap has developed a reputation for its versatility in both skin and soft tissue coverage and for restoration of elbow function in both flexion and extension. In a case presented, a large extra-abdominal desmoid was removed along with the entire deltoid and three-quarters of the triceps. The latissimus dorsi was elevated with a large overlying skin island and rotated on its neurovascular pedicle into the defect in the posterior shoulder and upper arm to replace the resected triceps and deltoid muscle, and to provide coverage in this region.

Bone contouring and fixation in functional, primary microvascular mandibular reconstruction

Experience in over 65 cases of microvascular mandibular reconstruction has resulted in the development of reliable techniques for bone fixation and contouring to achieve the best functional results. Methods of graft contouring and the application of rigid internal fixation are described in detail. Unusual situations in which the tumor extends through the buccal cortex of the mandible, and when condylar replacement is necessary, are presented. The options for managing these situations are discussed.

The internal oblique-iliac crest free flap in composite defects of the oral cavity involving bone, skin, and mucosa

The reconstruction of oromandibular defects following ablative surgery is a challenging undertaking. When the defect involves skin as well as mucosa, the challenge becomes even greater. The internal oblique iliac crest osteomyocutaneous free flap is particularly useful for reconstruction of through-and-through composite defects due to the inclusion of two separate soft-tissue flaps on the same vascular pedicle. We report our experience with this flap in the reconstruction of 10 patients with such defects. The utility, and the limitations of this form of reconstruction are discussed in detail.

Asthma in primary care patients. Challenges and controversies

Asthma varies in intensity, and patients must be treated as individuals to whom formulas do not apply. Often, the most difficult person to treat is the first-time patient whose clinical course is unknown and whose response to medications is totally untested. Although exacerbating substances should be avoided whenever possible, medication unfortunately is still needed by most asthmatic patients. At present, the choice of initial medication is subject to individual physician preference; beta 2-adrenergic agonists, cromolyn sodium (Intal), theophylline, and aerosol corticosteroids are all acceptable as first-line treatment. Addition of a second, third, or fourth medication again depends on individual response and physician choice. Patients with asthma need to be educated regarding the nature of the disease and its almost total unpredictability. Equally important is a frequent review of medications and a willingness to alter regimens as situations require.

The neurofasciocutaneous radial forearm flap in head and neck reconstruction: a preliminary report

The radial forearm free flap has achieved considerable popularity as a reconstructive technique due to its thin, pliable tissue and long vascular pedicle. The successful use of this flap as a carrier of a vascularized nerve to bridge motor nerve gaps and as a sensate flap has not been previously reported in head and neck reconstruction. The superficial branch of the radial nerve was used as a vascularized nerve graft to bridge a facial nerve defect following radical parotidectomy. The medial and lateral antebrachial cutaneous nerves were used to re-establish sensation in a reconstructed pharyngeal mucosal defect. The published clinical and experimental studies on vascularized nerves and sensate flaps are reviewed in detail.

Use of multiple dipole analysis for the classification of benign rolandic epilepsy

The clinical literature has suggested that while the clinical features and presentation of benign rolandic epilepsy in children (BREC) are known, the neuronal mechanism of the epileptic focus is poorly understood. Classification of clinical subtypes is usually made by determining whether there are supplementary clinical signs of brain damage, in which case the epilepsy is classified as non-benign or "atypical". Studies of EEG findings in BREC have suggested that the source of the epilepsy is in the Rolandic fissure. We investigated dipole source modelling in 24 children, comparing the results of one and two dipole models. The results indicate that atypical BREC patients have a more complex distribution of dipoles and that single dipole fits may be more predictive of typical BREC than multiple dipole fits. The implications of these results are discussed.

Free flap design in head and neck reconstruction to achieve an external segment for monitoring

Postoperative monitoring of the perfusion of a free flap used in head and neck reconstruction is vitally important in achieving a favorable outcome. There are a wide range of methods that have been advocated to assist in this surveillance. However, at this time, there is no one technique that is universally efficacious in detecting early arterial and venous occlusion. In our experience, the most reliable means of monitoring has been the clinical assessment of flap color, capillary refill, tissue turgor, and bleeding. To assess these parameters, a portion of the flap must be accessible for observation. When the defect is buried, as is often the case in head and neck reconstruction, flap design is critical to achieve a reliable external segment for monitoring. The methods for exteriorizing a well-vascularized portion of tissue in the most commonly used flaps are described.

Neuromagnetic fields accompanying unilateral finger movements: pre-movement and movement-evoked fields

Neuromagnetic fields accompanying voluntary flexions of the right index finger were studied in five subjects. In all subjects, slow magnetic fields were observed over the central scalp beginning about 1 second prior to movement onset. These fields displayed a similar time course to the electrically recorded "readiness potential", but with reversals of field direction over regions of the rolandic fissure over both hemispheres. Least-squares fitting of two current dipole sources for the pre-movement fields resulted in a consistent localization of one source in the region of the rolandic fissure contralateral to the side of movement in four subjects. Ipsilateral dipole sources fitted inconsistently at deeper locations or outside the head indicating the inability of a single dipole source to account for the ipsilateral fields. A large field reversal was also observed over the contralateral (left) hemisphere, 90-130 ms after onset of EMG activity in the active muscles. In some subjects, single dipole sources could be fitted to this "movement-evoked" field at locations slightly deeper and posterior to the pre-movement source locations in the contralateral hemisphere, possibly indicating unilateral activation of somatosensory cortex related to sensory feedback during the onset of this movement. Subtraction of pre-movement field activity from post-movement fields improved the ability to fit a single contralateral rolandic source for all subjects suggesting that pre-movement sources continue to be active during movement onset. These findings confirm previous reports that voluntary finger movements are preceded by slow magnetic fields.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of a topical PGE2 analogue on global flap ischemia in rats

The present study evaluated the ability of DHV-PGE2ME, a topically effective 16-vinyl prostaglandin E2 analogue, to improve the tolerance of skin flaps to a period of ischemia. DHV-PGE2ME and placebo were applied to bilateral island flaps on 70 anesthetized rats; then the vascular pedicle of each flap was clamped for 10 hours. Treated flaps evidenced significantly better reperfusion, as documented by quantification of fluorescein dye delivery at 90 minutes after clamp release, and they had significantly greater ultimate viability (p less than 0.05, by ANOVA). While less than 3 percent of untreated flaps survived, those treated with 1.75 and 17.5 microgram/cm2 of drug evidenced 76 and 86 percent survival, respectively. Treatment of a given flap did not affect its contralateral mate, since there was no evidence of a systemic effect. Especially since its effect can be limited to the site of application, DHV-PGE2ME should be valuable for the treatment of compromised perfusion in a variety of settings.

Functional mandibular reconstruction of patients with oral cancer

For the patient with oral cancer who has undergone quadrant resection, mandibular reconstruction provides normalization of the lower facial contour, regained architectural support, and reestablishment of occlusal relationships. Reconstruction with vascularized bone offers the most rapid rehabilitation. Replacement of dentition provides improved deglutition, mastication, and speech. In eligible patients the use of osteointegrated implants can provide rigid stabilization for dental prostheses. In previous studies these implants were placed in a secondary procedure. In the present study microvascular mandibular reconstruction was combined with primary placement of osteointegrated implants in the treatment of seven patients. Preliminary results indicate that the combination of procedures can provide more rapid and effective rehabilitation for the patient with cancer. Issues for further study are also identified.

Geometry of the vascular pedicle in free tissue transfers to the head and neck

Traditionally, the most important parameters for success in free tissue transfer have been expertise in performing small vessel anastomoses, meticulous donor site dissection, and careful recipient vessel preparation. It has been our experience, in free flap transfers for head and neck reconstruction, that a very crucial, often unrecognized, parameter is the geometry of the vascular pedicle. This term encompasses the three-dimensional positioning of the nutrient vascular pedicle as well as vessel tension and redundancy. The ideal axis for the lie of the vascular pedicle in the neck is in the longitudinal direction. This configuration helps to eliminate the kinking of the pedicle that is observed with side-to-side movements of the head. The primary objectives in recipient vessel selection are to use a healthy artery and vein and to perform the anastomoses in a location that provides easy access for the surgeon and assistant. Recipient vessel selection is also a major determining factor in the achievement of the desired pedicle geometry. We believe that the transverse cervical artery and the external jugular vein are the best recipient vessels for free tissue transfer. The reasons for this selection, as well as technical details to improve pedicle geometry, are discussed in depth. Representative cases that demonstrate pitfalls in vascular pedicle geometry are presented.

The internal oblique-iliac crest osseomyocutaneous microvascular free flap in head and neck reconstruction

The iliac crest osseocutaneous free flap, based on the deep circumflex iliac artery and vein, was a landmark contribution to head and neck reconstruction. Two major problems associated with this flap are the lack of flexibility in placement of the skin paddle with relation to the bone graft, and the excessive thickness of the skin paddle when used in the oral cavity. The scapular osseocutaneous flap has achieved recent popularity for mandibular reconstruction based, in part, on its thin skin paddle that is easily positioned in three dimensions with relation to the bone graft. However, the segment of bone that can be harvested from the iliac crest is superior to that of the lateral border of the scapula because of its increased length, thickness, and natural contour. In 1984 the internal oblique free muscle flap based on the ascending branch of the deep circumflex iliac artery was described for use in reconstruction of the extremities only. The authors introduce the application of the internal oblique-iliac crest osseomyocutaneous free flap for mandibular reconstruction. The mobility of the internal oblique muscle with relation to the iliac bone graft has permitted its use for inner mucosal defects or outer cutaneous defects when covered with a skin graft. Following denervation atrophy, the muscle component becomes a thin, pliable piece of tissue that easily conforms to three-dimensional defects of the head and neck. This increased flexibility, the established benefits of the iliac bone, and the ease of intraoperative positioning for a two-team approach make this composite flap an outstanding tool for mandibular reconstruction. Two representative cases and a detailed description of flap harvesting, insetting, and donor-site closure are presented.

Primary placement of osseointegrated implants in microvascular mandibular reconstruction

The goal of mandibular reconstruction is to rehabilitate the patient by restoring occlusal relationships, lower facial contour, oral continence, and a denture-bearing surface. One of the major advantages of the use of vascularized bone over all other methods of mandibular reconstruction is its ability to achieve dental rehabilitation rapidly. The use of osseointegrated dental implants is a valuable adjunct in oral rehabilitation. It provides the most rigid form of stabilization to withstand the forces of mastication. In situations in which soft tissue reconstruction or the height of the alveolar ridge is not sufficient for a tissue-borne denture, implants offer the most suitable alternative. Mandibular reconstruction with free tissue transfer techniques is ideally suited for the placement of implants. These can be inserted at the time of mandibular reconstruction. Four months after surgery, when the integration process has occurred, the implants are unroofed, loaded, and ready for prosthetic placement. We will present several representative patients who underwent mandibular reconstruction with microvascular free bone transfer who have been successfully rehabilitated by osseointegrated implants. The process of osseointegration, different types of dental implants, and issues regarding radiation and implants are discussed. This is the first report of dental rehabilitation by primary placement of dental implants in patients undergoing microvascular mandibular reconstruction.

Perfusion washout: increasing a microvascular free flap tolerance to ischemia

Thirty-five Sprague-Dawley rats were divided into control (non-exsanguinated) groups of 8 and 10 hr of ischemia, and exsanguinated groups of 8, 10, 14, 16, and 18 hr of ischemia. Free flaps based on the superficial inferior epigastric artery were anastomosed to the contralateral femoral vessels after their designated ischemia period. Reperfusion was assessed by measuring fluorescein uptake in the free flaps after clamp release. In the exsanguinated groups, 100 percent (5/5) of the 8-hr, 10-hr, and 14-hr ischemia groups survived; 80 percent (4/5) of the 16-hr ischemia group free flaps survived; and none (0/5) of the 18-hr ischemia flaps survived. In the control groups, 100 percent (5/5) of the 8-hr ischemia flaps survived, while none (0/5) of the control 10-hr ischemia flaps survived. Fluorescein uptake correlated well with flap survival. By exsanguinating an experimental microvascular free flap prior to its ischemia period, it is possible to dramatically increase flap tolerance to ischemia.

The internal oblique-iliac crest osseomyocutaneous free flap in oromandibular reconstruction. Report of 20 cases

Microvascular free tissue transfer techniques using composite flaps are the most reliable method for the combined bone and soft-tissue reconstitution of oromandibular defects. Functional oromandibular reconstruction requires that maximum tongue mobility be achieved along with dental prosthetic rehabilitation. The internal oblique-iliac crest osseomyocutaneous microvascular free flap was used in 20 patients for oromandibular reconstruction. The internal oblique muscle, based on the ascending branches of the deep circumflex iliac artery and vein, was used to resurface mucosal defects of the oral cavity and pharynx. The iliac bone, because of its length, width, and natural contour, is the best source of vascularized bone for mandibular reconstruction. The improved soft-tissue component of this composite flap markedly improved the functional results. Reconstruction failed in one patient. Eleven patients underwent dental rehabilitation with either a tissue-borne or osseointegrated implant-borne denture. Follow-up of longer than one year showed minimal donor site morbidity.

Functional imaging of brain responses to repetitive sensory stimulation: sources estimated from EEG and SPECT

This study examined the effect of modality of stimulation on two measures of cerebral function: (a) the scalp distribution of sensory evoked potentials and (b) the cerebral distribution of radiolabelled HMPAO. Steady-state stimulation in the auditory, somatosensory or visual modality was presented to six subjects. Scalp potentials were measured from a distribution of electrodes, and the radiopharmaceutical was injected through an indwelling intravenous catheter midway through the stimulation/recording session. Equivalent dipole sources estimated from the spatial distribution of the scalp potentials were found to be consistent with regions of high HMPAO uptake as imaged by Single Photon Emission Computed Tomography (SPECT).

The relationship between extracellular matrix vesicles and the calcifying front on the 21st day after injury to rat tibial bone

The relationship between extracellular matrix vesicles and the calcifying fronts was examined by studying vesicular diameters and types. Transmission electron microscopy combined with computerized morphometry three weeks after injury to the tibial bone in rats was used. The different vesicle types were defined as: (1) vesicles with electron lucent contents referred to as empty; (2) vesicles with amorphous electron opaque contents, called amorphic; (3) vesicles containing crystalline depositions, called crystalline; and (4) vesicles containing crystalline structures with ruptured membranes, referred to as ruptured. The diameters of most vesicles ranged between 0.07 and 0.17 micron. More than 95% of the vesicles were located less than 2 micron from the calcified front. The vesicles were distributed among the categories as follows: empty, 9.6%; amorphic, 19.3%; crystal, 39.2%; and ruptured, 31.9%, respectively. The diameters of the crystalline and ruptured vesicles were significantly larger than those of the empty and amorphic types. The ruptured type had the largest diameters. The sequence of distances from the calcified front was recorded as follows: ruptured, crystalline, amorphic, and empty, with the ruptured and crystalline types being the closest to the front. This study supports the accepted theory on matrix vesicle mineralization. The cell is responsible for secretion of empty vesicles that accumulate amorphous Ca and Pi to form a hydroxyapatite crystal. This is followed by rupture of the vesicular membrane. The propagation of the process is accompanied by an increase in the vesicular diameter and its approximation to the calcifying front.

Personality and smokeless tobacco use

Smokeless tobacco use and personality factors associated with smokeless tobacco use were examined in a broad, representative sample of 8th and 10th graders from central and south-central Florida (n = 1413). Current, occasional, or ex-users of smokeless tobacco accounted for 51% of the males and 9% of the females. Smokeless tobacco users, as compared to non-users, had significantly higher Trait Anger, and Angry Temperament and Angry Reaction subscale scores on the State-Trait Personality Inventory, suggesting a possible role in the initiation of smokeless tobacco use. There were no differences in Trait Anger, Anxiety, or Curiosity scores between the three user groups, suggesting that trait personality does not play a role in the maintenance of smokeless tobacco use.

Comparison of skin surface fluorescence and fluorescein tissue concentration with the dermatofluorometer

Recently sodium fluorescein has been used to determine viability of tissue and assess blood flow. No study, however, has documented the correlation of surface fluorescence as measured by the dermatofluorometer with the actual distribution of fluorescein in tissue. Abdominal skin flaps were raised on Sprague-Dawley rats. Following intravenous injection of sodium fluorescein, skin surface fluorescence was measured and compared with tissue fluorescein concentration. This study confirms that skin surface fluorescence correlates well with actual fluorescein distribution in tissue. Furthermore, the study clearly illustrates the statistically significant variation of surface fluorescence as a function of distance from the vascular pedicle.

Topographic distribution of the 40 Hz auditory evoked-related potential in normal and aged subjects

Galambos, Makeig and Talmachoff (1981) described what they called the 40 Hz event-related potential (ERP). This steady-state response is an EEG following response to repetitive auditory stimulation which becomes sinusoidal in form and maximal in amplitude at rates between 35 and 45 Hz. The present study was designed to examine the scalp topography of the 40 Hz ERP in order to complement previous magnetoencephalographic studies which implicate auditory cortex in the generation of the response. In addition, this study was designed to collect normative data on an aged sample in order to assess the effects of aging on the response. 40 Hz ERP's were recorded from a group of seven audiometrically and neurologically normal elderly subjects (mean age = 69.6 years) and a younger group of five normal adults (mean age = 38.0 years), using 1000 Hz tones presented binaurally at 40 per second. A 21 channel recording system was used to obtain a comprehensive picture of the scalp distribution of the response. Recorded ERP's were Fourier transformed to enhance the signal-to-noise ratio. No significant differences were found in phase or amplitude of the 40 Hz ERP between the two age groups, indicating that the normal aging process does not have an effect on this response. Topographic maps of the 40 Hz ERP showed reversals of electrode potential in temporal regions, supporting an interpretation of bilateral sources in temporal cortex. The data presented in this study complement previous studies of the 40 Hz event-related magnetic field and support the position that temporal cortex is involved in the generation of the response.