Extended anterior subcranial approach for skull base tumors: long-term results.

The extended anterior subcranial approach differs significantly from more traditional surgical approaches to the skull base in that it allows a broad inferior access to the anterior skull base planes with tumor exposure from below rather than via the transfrontal route. The authors initially used the subcranial approach in 1978 for the treatment of high-velocity skull base trauma and certain craniofacial anomalies. In 1980 they expanded the indications to include the combined neurosurgical-otolaryngological resection of various skull base tumors. Osteotomy of the frontonasoorbital external skeletal frame provides optimum anterior access to the orbital and sphenoethmoidal planes as well as to the nasal and paranasal cavities while avoiding frontal lobe retraction and the external facial incisions characteristic of transcranial and transfacial approaches. The improved visualization of the anterior skull base and clival-sphenoidal region facilitates en bloc tumor removal, optic nerve decompression, exposure of the medial aspect of the cavernous sinus, and watertight realignment of the anterior cranial base dura. In this report the authors present their experience over the past 13 years with 104 patients who underwent operation via the extended subcranial approach. Because extensive frontal lobe manipulation and external facial incisions are avoided with this approach, intensive care unit and overall hospital stay are reduced, related complications are minimized, and postoperative cosmetic appearance is enhanced. The extended anterior subcranial method is therefore an excellent alternative to traditional transfacial-transcranial skull base approaches for the removal of selected skull base tumors.

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.

Temporal factors affecting the secondary critical ischemia of normothermic experimental skin flaps.

In free tissue transfer surgery all flaps are subjected to a primary ischemic episode prior to reperfusion. Some flaps may fail due to a second ischemic insult in the postoperative period. The maximum allowable time for salvage of such failing flaps is referred to as the secondary critical ischemia time. Unilateral abdominal island skin flaps based on the superficial inferior epigastric vessels were raised in 96 Sprague-Dawley rats. Animals were divided into 24 groups of four rats each. Normothermic ischemia was produced by applying microvascular clamps to the vascular pedicles. The flap groups were subjected to combinations of primary ischemia, reperfusion, and secondary ischemia. Flap survival was assessed on the seventh postoperative day. Flap survival decreases significantly with increased primary and/or secondary ischemia time and decreased reperfusion period. Moreover, a longer primary ischemia and/or shorter reperfusion decrease the tolerance of the flap to a second ischemic insult.

Long-term results of dermal grafting for the repair of nasal septal perforations.

The closure of nasal septal perforations is a significant surgical challenge with a high failure rate. Dermis placed between mucoperichondrial advancement flaps may be an alternative. The usefulness of dermal grafting for the repair of nasal septal perforations was initially investigated in an animal model. Four pigs had 1.5 x 2.5 cm perforations surgically created and closed with either temporalis fascia or dermis placed under a local mucoperichondrial flap. The dermal graft group had an average closure of 80% with histologically normal mucosal surfaces. The temporalis fascia group had no closure. Fourteen patients with chronic nasal septal perforations from iatrogenic causes, trauma, and drug abuse were repaired with dermal grafting. Nine patients had complete closure, 3 patients had partial closures, and 1 patient's graft dislodged on the first postoperative day. Dermal grafts placed between mucoperichondrial flaps are a viable alternative for the closure of nasal septal perforations.

Repair of zygomaticomalar complex fractures. The Swiss method.

The zygomaticomalar complex fracture, also known as the trimalar, tripod, or tetrapod fracture, is a fracture commonly encountered by facial plastic surgeons. Failure to correctly reduce these fractures can lead to facial asymmetry, trismus, diplopia, enophthalmos, and parasthesias. Approaches to the zygomaticomalar complex have been well documented in the literature and include the transconjunctival lateral canthotomy, subciliary blepharoplasty, brow, gingivobuccal, and coronal incisions, or some combination thereof. Fracture fixation is accomplished by the internal placement of miniplates and microplates across properly reduced fracture lines to resist torsional rotation and masticatory distraction. The method of fracture reduction and fixation employed at the University Hospital of Bern, Switzerland, shares much with previously published and accepted methods of medial and lateral buttress reconstruction, but it introduces several original concepts in an attempt to maximize functional and aesthetic outcomes.

Revascularized bone grafts for craniofacial reconstruction.

Reconstruction of craniomaxillofacial defects caused by injury, tumor ablation, or congenital deformities can be accomplished by a variety of methods. Nonvascularized (free), vascularized (pedicled), and revascularized (microvascular) bone grafts have been employed for osseous restoration of the upper, mid, and lower facial skeleton. In comprised recipient tissue beds or when rapid functional restoration is desired, revascularized flaps hold certain advantages over their nonrevascularized counterparts. The revascularized flaps used most commonly for craniofacial reconstruction are discussed with regard to anatomy, clinical applications, and aesthetic and functional limitations.

SOOF lift and lateral retinacular canthoplasty.

Eyelid rejuvenation surgery may be slowly shifting from pure fat removal techniques to those that preserve and reposition the periorbital fat. The traditional subciliary incision blepharoplasty was fraught with minor and major complications, and while the transconjunctival blepharoplasty afforded lower morbidity, its inability to address all aspects of periorbital rejuvenation eventually limited its popularity. Coincidentally, a search by aesthetic surgeons was on for better techniques to lift the midface, soften the nasolabial fold, and efface the tear trough deformity. In an effort to avoid the lid malposition complications that often accompany transblepharoplasty cheek lifting, innovative canthoplasty and canthopexy techniques were developed, which paved the way for a safe return to subciliary blepharoplasty surgery. Effacement of the tear trough deformity, now considered to be a major determinant in successful periorbital rejuvenation, could be achieved through fat repositioning and without the use of alloplastic implants or free fat grafts, thus improving reliability while minimizing complications. By preserving periorbital fat the hollowed out orbit, often seen after traditional blepharoplasty, could be avoided. The technique described in this article is a composite of several previously published approaches, is simple for the experienced blepharoplasty surgeon to master, and has been used with safety and reliability over the past 18 months in the senior author's practice.

BoneSource for craniomaxillofacial reconstruction.

Hydroxyapatite cement (HAC) is a calcium phosphate cement whose properties overcome the inherent limitations of previous forms of hydroxyapatite. HAC (BoneSource, Leibinger Corp., Dallas, TX) is prepared as a powder that forms an easily applicable paste which hardens in six to 20 minutes. HAC exhibits excellent biocompatibility, is easily contoured in situ, is highly stable, and allows osteoconduction. The use of calcium phosphate cements (CPC) for reconstruction of craniofacial defects has intrinsic appeal owing to the chemical and physical properties of hydroxyapatite. Difficulty in contouring CPC implants, their lack of compressive strength, and their failure to allow osteoinduction were significant limitations in the use of earlier forms of hydroxyapatite for skeletal reconstruction. HAC offers an excellent reconstructive option for repair of various craniofacial defects.

New approach for operative management of vascular lesions of the infratemporal internal carotid artery.

Direct operative management of aneurysms of the internal carotid artery is associated with significant morbidity. Preauricular surgical approaches to this area can result in violation of the inner ear, temporomandibular joint, or mandibular ramus, and cranial nerves V, VII, IX, X, XI, and XII. A new technique for saphenous vein bypass of the infratemporal and petrous internal carotid artery, using a postauricular curvelinear groove drilled in the mastoid cortex, is described. Proximally, the reverse vein graft is anastomosed to either the internal or external carotid artery, whereas the distal anastomosis is to the horizontal petrous internal carotid artery. The latter is accessed through a small pterional craniotomy. The internal carotid artery is then ligated between points of anastomosis, thus isolating the lesion and eliminating dissection in the infratemporal fossa. The posterior location of the vein graft also avoids potentially infected areas adjacent to the oropharynx, nasopharynx, and soft tissues of the face. Use of the external carotid artery decreases carotid cross-clamp time and minimizes graft length, and creation of a bony canal protects the graft from subsequent compression and kinking.

Native valve endocarditis due to Bartonella henselae in a middle-aged human immunodeficiency virus-negative woman.

We report the case of a human immunodeficiency virus-negative woman who developed native valve endocarditis of the aortic valve due to Bartonell henselae infection. The diagnosis was established using serology and PCR analysis of excised aortic valve tissue.

The use of a new perfusate in experimental microvascular flaps: a threefold increase in ischemic tolerance.

The benefit of perfusion washout in both experimental and clinical skin flaps has long been debated. By perfusing ischemic rat pedicled flaps with UW solution, a recently developed, high-molecular-weight, organ-preservation medium, a 170 percent increase in the critical ischemia time of treated versus untreated control flaps was demonstrated. Sixty rats were used in this study. A 3- x 6-cm unilateral abdominal skin flap based on the superficial inferior epigastric artery and vein was raised. The flaps were divided into three groups: Group 1 (control--no perfusion washout (n = 15); Group 2 (LR)--perfusion washout with lactated Ringer's solution (n = 15); Group 3 (UW)--perfusion washout with UW solution (n = 30). Flaps were subjected to varying periods of ischemia, ranging between 8 and 30 hr. The primary ischemia time at which 50 percent of the flaps survived clinically was 10 hr for Group 1, 15 hr for Group 2, and 27 hr for Group 3. The differences between the survival rates for flaps in Groups 1, 2, and 3 were statistically significant (p less than .0005). By bathing the vascular and parenchymal cells in an impermeant preservation solution, it was hypothesized that cellular swelling would be inhibited, thereby significantly improving a skin flap's tolerance to warm ischemia. Furthermore, after reviewing the pertinent literature, it is evident that the primary critical ischemia time of 27 hr is the highest reported to date for the normothermic experimental rat pedicled flap. Clinical application of these findings, as well as the need for further studies, are discussed.

In vitro hepatic insulin resistance in chronic pancreatitis in the rat.

To investigate the effect of chronic pancreatitis (CP) on in vitro hepatic sensitivity to insulin, the suppression of glucagon-stimulated hepatic glucose production (HGP) by insulin was examined during isolated liver perfusion (ILP) in CP and sham-operated rats. CP was induced at laparotomy by infusion of 50 microliters 99% oleic acid into the common bile duct during temporary occlusion of the proximal hepatic duct in 250- to 350-g Sprague-Dawley rats. Eight to sixteen weeks later, single-pass ILP was performed on fed animals. Glucagon (100 pg/ml) was infused for 30 min; the final 20 min of perfusion was performed with (a) no insulin, (b) 25 microU/ml insulin, or (c) 100 microU/ml insulin. CP and sham rats demonstrated comparable HGP responses to glucagon during the 0- to 10-min period (5.2 +/- 0.5 vs 5.9 +/- 0.5 mg/g/min, P = NS). CP rats demonstrated an HGP response to glucagon alone more evanescent than that in sham rats (20-30 min of HGP, 6.6 +/- 0.6 vs 9.5 +/- 0.4 mg/g/min, P less than 0.05). Sham rats showed a dose-dependent inhibition of HGP by insulin, however (percentage 20-30 min of HGP/0-10 min of HGP for 0, 25, and 100 microU/ml insulin: 166 +/- 12, 125 +/- 7, and 101 +/- 5%, P less than 0.01), whereas CP rats showed no effect of insulin (130 +/- 6, 123 +/- 7, 134 +/- 7%, P = NS). Pre- and postperfusion liver glycogen contents revealed comparable decreases in liver glycogen in both groups: insulin inhibition of HGP in sham rats was accompanied by higher postperfusion glycogen content. These data demonstrate a loss of insulin-mediated suppression of hepatic glucose production in livers obtained from pancreatitic rats. We conclude that CP is accompanied by a primary hepatic resistance to insulin; this defect may play a role in the etiology of pancreatogenic diabetes.