Microdialysis in clinical practice: monitoring intraoral free flaps

Clinical examination is still the gold standard of postoperative free flap monitoring, but with intraorally situated and/or buried flaps, it can be difficult or impossible. Microdialysis is a sampling technique which offers the possibility to monitor the metabolism of a flap continuously. Ischemia can be detected by monitoring the changes in glucose, lactate, and pyruvate levels in interstitial fluid of the specific tissue. Our aim was to use microdialysis to monitor the metabolism of free flaps used for reconstructions inside the oral cavity/oropharynx and to evaluate the reliability and usefulness of this new monitoring method.Twenty-five consecutive patients who underwent oral cavity/oropharynx cancer resection and immediate reconstruction with free flap were included in the study. A microdialysis catheter was placed into the subcutaneous adipose tissue of the flap in the end of the surgical procedure. Dialysate samples were taken on an hourly basis for 72 hours postoperatively. Routine clinical monitoring was carried out by experienced nursing staff. Clinical findings were recorded and later compared with microdialysis values.Two flaps out of 25 failed in spite of reoperations. In both problem cases, microdialysis indicated ischemia 1 to 2 hours before it became clinically evident. During flap ischemia, the lactate/pyruvate ratio increased, glucose concentrations reduced, whereas lactate level increased when compared with normal values.Our results indicate that microdialysis is safe for the patient and the flap. It can reliably detect flap ischemia at an early stage. This is especially useful in buried flaps when clinical monitoring is difficult. Microdialysis may also reduce the patient discomfort caused by repeated clinical examination of the flap.     

Oral functional outcome after intraoral reconstruction with nasolabial flaps.

In this study, the functional and aesthetic outcome of patients with nasolabial flaps in the floor of the mouth was examined. Sixteen patients underwent reconstruction of the floor of the mouth with 19 nasolabial flaps after resection of a squamous cell carcinoma. Eight patients received postoperative radiotherapy. The patients were questioned concerning oral disabilities. Speech, mastication, deglutition, oral continence and the aesthetic result were evaluated. Two-point discrimination, temperature sensation and blunt-sharp discrimination of the intraoral flaps were tested. Speech and the wearing of dentures were hardly affected. Consumption of solid foods caused moderate problems in half of the patients. No sensibility problems were found. The aesthetic deformity was minimal. The use of nasolabial flaps in patients with limited defects of the anterior floor of the mouth after tumor resection showed adequate functional and aesthetic results.     

Skin grafts used in combination with free flaps for intraoral oncological reconstruction

Surgeons have relied less on skin grafts for intraoral reconstruction by extending free flap tissue onto adjacent areas that could be potentially skin grafted. Split-thickness skin grafts provide thin, reliable epithelial coverage to tissue beds that can be grafted without requiring additional flap tissue. The combined use of split-thickness skin grafts with free tissue transfer may be advantageous in select situations. Four patients underwent intraoral tumor resection with immediate reconstruction using free tissue transfer and split-thickness skin grafts. Skin grafting the tongue component of combined hemiglossectomy and floor-of-mouth (FOM) defects rather than spanning the tongue-FOM junction with flap tissue may prevent excessive bulk, improve tongue mobility, and reduce the size requirement of the flap. A split-thickness skin graft can be applied to the intraoral surface of free flaps used to reconstruct through-and-through orocutaneous defects, reducing the complexity of flap design and inset. Maxillectomy defects reconstructed with muscle flaps can be epithelialized immediately with the application of a split-thickness skin graft to provide a stable obturator cavity. In select cases, the combination of split-thickness skin grafts and free tissue transfer may have advantages over the use of flap tissue alone to cover the adjacent areas of a complex defect capable of being grafted.     

Do intraoral radial forearm free flaps re-mucosalise and is candida infection relevant?

Eleven patients, with a mean age of 57 years, who had undergone radial forearm flap reconstruction following the excision of intraoral carcinoma, underwent flap biopsy at a mean of 45 months postoperatively. Seven of the patients had received postoperative radiotherapy. In eight patients the clinical appearance of the flap was similar in colour to that of adjacent normal oral mucosa; the remaining flaps retained the appearance of normal volar forearm skin. Histological examination of the flaps showed varying degrees of telangiectasia and mild chronic inflammation. In only two patients was superficial infection by candida hyphae identified. Intraoral free flaps, although clinically resembling oral mucosa, retain histological features of skin, at least within the period under study. The erythematous clinical appearance was not correlated with the presence of chronic fungal infection, but reflected the presence of vascular repair tissue, telangiectasia and mild residual chronic inflammation.     

Microscopic and immunohistochemical analysis of the skin changes of free forearm flaps in intraoral reconstruction

In the literature, few studies based on clinical and histological evaluation analyze skin structural changes after transplantation to the oral cavity. Ten patients affected by squamous cell carcinoma of the oral cavity who were reconstructed with a free forearm flap were included in the current study to analyze skin alterations. The authors performed a histological and ultrastructural evaluation of skin samples from the free forearm flap before transplantation and 18 months after intraoral reconstruction. They analyzed cytokeratin and involucrin distribution, which represent markers of maturation and differentiation of epithelia. The aim of this study was to demonstrate whether skin "mucosalization" occurs. They found that the skin undergoes some morphological changes induced by the intraoral environment. Cytokeratin and involucrin distribution is mostly unchanged. This aspect is in favor of skin structure preservation. Thus, they found that "mucosalization" of the skin is not evident after 18 months.     

In situ skin grafting of free muscle flaps prior to microvascular transfer to provide intraoral lining for full-thickness defects

Background. Previously, the importance of providing skin for intraoral lining for full-thickness mucocutaneous defects has been emphasized. More recently, simple skin grafting of the intraoral portion of muscle flaps has been described. Methods. Six patients were evaluated who had full-thickness mucocutaneous defects reconstructed by means of free muscle flaps with skin grafting of the intraoral muscle surface. An illustrative case is provided. A technique of preplacing the skin graft on the muscle prior to microvascular transfer is described. Mucosal biopsies were performed at the reconstruction site. Results. All patients had complete take of the skin grafts. No fistulas occurred. Functional and esthetic results were satisfactory. Conclusions. The ideal candidate for this form of reconstruction is one in whom there is a large, full-thickness mucocutaneous defect. Preplacement of the skin graft reduces ischemia time, allows suturing of the skin graft to the muscle surface outside the narrow confines of the oral cavity, and enables placement of multiple quilting sutures that secure the graft against shear forces and so obviate the need for a stent dressing. © 1995 Jons Wiley & Sons, Inc.     

A conceptual approach to local flaps

Few procedures offer the surgeon a greater opportunity to exercise his surgical and aesthetic judgement than the design and implementation of local flaps about the head and neck. Considerations include skin color and texture match; adequacy of flap blood supply; size, location, and characteristics of the donor site defect; functional capability of the proposed flap; nature of skin tension lines created; and number of surgical procedures required. A systematic approach to local flap design and implementation is presented, and illustrations of the geometric principles involved are included.     

Cryotherapy of intraoral leukoplakia

In an investigative study sixty patients with single and multiple areas of leukoplakia were treated by cryotherapy.     

Electrocoagulation for intraoral cancer

Electrocoagulation of 58 intraoral lesions (1 to 6.5 cm in diameter) resulted in a three-year absolute disease-free survival rate of 59% (34/58). During the 20-year study, 43 (74%) of the 58 patients were cured. Though an initial 28% local failure rate was observed, 31% (5/16) of these patients were subsequently cured by a second electrocoagulation. Electrocoagulation has distinct advantages over conventional surgery and irradiation. Relatively little tissue beyond the tumor is coagulated. Such tissue sparing allows better postoperative function and cosmesis. The deleterious effects of irradiation, including the serious "dry-mouth" syndrome, are avoided. These treatment results are competitive with those of conventional surgery and irradiation. The limited field treated, the tissue conservation, the minimal morbidity, and the cost-effectiveness should make electrocoagulation a real consideration in treating selected invasive intraoral tumors. Ideally suited for electrocoagulation are those patients whose lesions are small, easily visualized, mobile, and well differentiated.     

A comparison of arterial and venous flaps.

The survival rate and elastic properties of the anterior abdominal skin flap in Sprague-Dawley rats were studied in three groups of animals. In group 1 where the flaps were supplied by a normal artery, arterial flaps (1A) had better survival rate and elastic properties than venous flaps (1B). In group 2, where the flaps were supplied by an artery with diminished perfusion pressure, the arterial flaps (2A) still had slightly better results than venous flaps (2B). However, in group 3 where the flaps were supplied by a vein, venous flaps (3B) had better results than arterial flaps (3A).     

A review of nasolabial flaps for intra-oral defects

The nasolabial flap has been used in 23 patients for reconstruction of moderate size intra-oral defects. Versatility in design of the flap is allowed by the numerous blood vessels supplying the nasolabial skin. Flap vascularity was reliable, there being no cases of total loss and three cases (12%) of partial necrosis. Recurrence of tumour occurred in 8.7% of cases and in those operated in the first instance for recurrence, there was no further local disease. There were minor problems of intra-oral hair growth, donor site distortion and obstructive sialadenopathy. However, because of its simple elevation, proximity to the defect and versatility, we believe that the nasolabial skin flap is a useful procedure for closure of selected intra-oral defects.     

A microcirculation observation of the venous flaps]

This article presented the observation results of microcirculation of 84 island venous flaps performed on the ears of 42 rabbits. The survival rates of 5 groups divided by differently handling the vessel pedical of the flaps were: 1. maintaining artery and venous 90.36%. 2. maintaining distal and proximal venous 86.29%. 3. only maintaining proximal venous 75.71%. 4. only maintaining distal venous 28.75%. 5. ligating all vessels O(P < 0.01). The results of blood flow examined by laser Doppler and the number of micrangium counted by microcirculation microscope were decreasing upon the sequence of the above groups (P < 0.05). We found that there were exact microcirculation in the venous flaps of group 2, 3, 4, but the blood flow in these groups, especially the group 4, were slower than the group 1.     

A treatment algorithm for the management of intraoral burns: A narrative review

Oral mucosa follows a distinctly different trajectory of wound healing than skin. Although there are contemporary guidelines regarding treatment of burns to the skin, there is no standard of care specific to intraoral burns. This narrative review proposes an evidence-based treatment algorithm for the management of intraoral burns. Data was collated through a comprehensive review of the literature and only included studies that have reported particular success with favorable short- and long-term prognoses. In order to critically appraise the strength of the treatment recommendations, the GRADE criteria was applied to each arm of the algorithm. The algorithm was initially subdivided into the four primary etiologies of intraoral burns — thermogenic, cryogenic, chemical, electrical. Our findings emphasize the importance of conservative modalities of intra-oral burn treatment.