Cranial nasal bone grafts

Reconstitution of the nasal scaffolding with maintainence of soft tissue proportions either following severe facial trauma or as a sequela to aesthetic rhinoplasty misadventures frequently is best achieved using the stability afforded by bone grafts. Split cranial bone grafts offer many advantages and may be the donor site of choice, and may even allow such surgery to be performed on an outpatient basis in some cases. The use of miniplate or screw osteosynthesis, now commonly accepted as a superior technique in craniomaxillofacial procedures, may simplify fixation of these calvarial nasal bone grafts with an apparent decrease in the risk of resorption.     

Preliminary assessment of laser Doppler flowmetry for determining timing of division of the cross-finger flap

The elapsed time before division of the cross-finger flap depends on adequate neovascularization from the recipient digit. Although subjective assessment of capillary filling in the flap after application of a tourniquet to the donor finger usually is accurate, on occasion, interpretation of observations may be equivocal. In these circumstances, noninvasive office measurement with use of the laser Doppler permits a sequential determination of relative flap perfusion. This objective data facilitates an appropriate clinical decision by the hand surgeon to ensure flap viability after pedicle division.     

Miniplate washers for improving lag screw fixation

Increased efficiency in using the lag screw principle for rigid fixation of bone, particularly for fragile cortical or soft cancellous grafts, is facilitated by dispersion of screw head compression forces with a biocompatible metallic washer. Although none is commercially available, such washers may be quickly fashioned from the residua of any adaptation miniplate in quantities as required.     

Recognition of potential morbidity after use of the radial artery as a conduit for coronary artery revascularization

The use of the radial artery as an alternative vascular conduit for coronary bypass surgery has become increasingly popular. The plastic surgery experience with radial forearm flaps has shown that sacrifice of the radial artery is not always a benign maneuver. The potential morbidity after using this conduit donor site in terms of hand dysfunction or wound healing problems can be significant, and frequently must ultimately be addressed as part of the role of the reconstructive surgeon. Case examples of skin necrosis, subsequent forearm wound infection and hypertrophic scarring after radial artery harvest are presented to introduce this as a real concern and to allow a review of the entire spectrum of potential problems in this regard. Any selection process where the radial artery may be chosen as the coronary revascularization conduit must anticipate these known donor site complications.     

Mortality studies of machining fluid exposure in the automobile industry III: A case-control study of larynx cancer

A case-control study of larynx cancer was conducted within a cohort of automobile workers exposed to metal working fluids, commonly referred to as machining fluids (MF). Results are based on 108 cases of larynx cancer and 5:1 matched controls. Risks associated with specific types of MF, as well as specific components of the fluids were evaluated. Based on a retrospective exposure assessment, lifetime exposures to straight and soluble fluids, grinding particulate, biocides, selected metals, sulfur, and chlorine were examined. Exposure to asbestos and acid mists at two of the three study sites was also characterized. Results suggest that straight mineral oils are associated with almost a two-fold excess in larynx cancer risk. There was also evidence of an association with elemental sulfur, commonly added to straight MF to improve the integrity of the materials under extreme pressure and heat. It is not clear whether sulfur is causally related to an excess relative risk of larynx cancer or whether the observed association is the result of unmeasured confounding by another contaminant or process feature. For example, the high stress operations that require MF enriched with sulfur are also more likely to produce polycyclic aromatic hydrocarbons (PAHs) during the process. Thus, the observed association with sulfur may be due to an association with PAH. The finding of excess risk of laryngeal cancer associated with MF is consistent with several previous reports in the literature. This is the first study, however, to distinguish straight mineral oils from other types of MF. Based on these findings, a general reduction in concentrations of straight mineral oil particulate in occupational environments would be prudent.     

Bipedicled fasciocutaneous flaps in the lower extremity.

It is well known that a bipedicled skin flap permits survival of longer flaps due to the secondary recruitment of vascularity. Inclusion of the deep fascia with such a flap, obeying the principles of the single-pedicled fasciocutaneous flap, provides even greater security for the immediate transposition of yet larger or riskier flaps without the need for delay maneuvers. This variation is especially valuable for the management of difficult wounds encountered in the lower extremity when no other local options may be available. Thirteen local bipedicled fasciocutaneous flaps including both vertical and horizontal orientations, without isolation of any discrete fascial perforators, have been successfully used for soft tissue coverage in the distal leg and ankle with only three (23%) minor complications as untoward sequelae. Another major advantage of this bipedicled version of the fasciocutaneous flap was that the inclusion of a distal pedicle simultaneously may be designed to prevent bone or tendon exposure at the donor site that otherwise frequently is a concern with a unipedicled flap.     

Closure of the ulnar forearm free flap donor site using a local radial forearm flap.

Thin, pliable cutaneous flaps with large calibre vessels ideal for microsurgical transfers are major attributes of the reliable forearm fasciocutaneous flaps. A major detriment, however, that must always be considered is the management of the residual donor site deformity. Just as this potential morbidity for small radial forearm free flap donor sites may be minimised by the V-Y advancement of a local ulnar forearm flap, the converse, using a local radial forearm flap for closure of the ulnar forearm free flap donor site, may be efficacious.     

Cyanide and migratory birds at gold mines in Nevada,USA

Since the mid-1980s, cyanide in heap leach solutions and mill tailings ponds at gold mines in Nevada has killed a large but incompletely documented number of wildlife (>9,500 individuals, primarily migratory birds). This field investigation documents the availability of cyanide at a variety of typical Nevada gold mines during 1990 and 1991, describes wildlife reactions to cyanide solutions, and discusses procedures for eliminating wildlife loss from cyanide poisoning. Substantial progress has been made to reduce wildlife loss. About half of the mill tailings ponds (some up to 150 ha) in Nevada have been chemically treated to reduce cyanide concentrations (the number needing treatment is uncertain) and many of the smaller heap leach solution ponds and channels are now covered with netting to exclude birds and most mammals. The discovery of a cyanide gradient in mill tailings ponds (concentration usually 2–3 times higher at the inflow point than at reclaim point) provides new insight into wildlife responses (mortality) observed in different portions of the ponds. Finding dead birds on the tops of ore heaps and associated with solution puddling is a new problem, but management procedures for eliminating this source of mortality are available. A safe threshold concentration of cyanide to eliminate wildlife loss could not be determined from the field data and initial laboratory studies. New analytical methods may be required to assess further the wildlife hazard of cyanide in mining solutions.     

Compatibility and stability of bryostatin 1 in infusion devices

Bryostatin 1 is currently in phase II clinical trial sponsored by the National Cancer Institute as an anticancer chemotherapeutic agent. Bryostatin 1 for injection was supplied in a dual pack containing a drug vial and a diluent vial and was manufactured by Ben Venue Laboratories, Inc (Bedford, OH). The stability and compatibility of the bryostatin 1-PET formulation, diluted to 1 and 10 ug/mL in saline and benzyl alcohol preserved saline, with polypropylene (PP) and polyvinyl chloride (PVC) bags at room temperature (27°C) were studied. All experiments were conducted in triplicate and analyses were performed using a validated, stability-indicating, high performance liquid chromatography (HPLC) assay.Bryostatin 1 solutions were compatible with PP bags. At both concentrations and with both salines, the bryostatin content remained unchanged during the 28-day storage period, benzyl alcohol concentration in the preserved saline solutions also remained relatively constant. In PVC bags, however, a decrease in bryostatin 1 concentrations without generation of decomposition products was observed at both dilutions and with both salines during the 28-day storage. A decrease in benzyl alcohol concentration in the preserved saline was also observed. While no diethylhexylphthalate (DEHP) leakage into the solution was observed in PP bags, DEHP leakage in PVC infusion bags was observed on day 2 of storage which increased with storage time and leveled off on day 6. The amount of DEHP leached into drug solution is dependent on the drug concentration. This study suggests bryostatin-PET formulation diluted with preserved saline can be used for long-term (4 week) intravenous administration using PP infusion bags, but not with PVC bags.