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Biomedical subjects

W C Lineaweaver

Publications and source records attributed to W C Lineaweaver.

At least 91 records · Page 5Linked to original sources
PubMed1994

Physiological implications of gastric transplantation for reconstruction of the cervical esophagus.

Transplantation of segments of stomach has been proposed and used as a clinical technique for reconstruction of the cervical esophagus. Review of reports of these operations reveals that the gastric antrum is most frequently used for flap tissue. Based on knowledge of the functions of the gastric antrum, prediction of complications of gastrin physiology and gastric emptying could be anticipated after transplantation of the antrum from its normal anatomical site. Although clinical complications suggestive of antral dysfunction are included in reports of clinical gastric transplantation, none of the investigators or practitioners of this procedure have comprehensively investigated the physiological consequences of gastric transplantation. This procedure raises a number of complex physiological issues that should be thoroughly examined experimentally before this operation can be safely used clinically.

Animals↗
PubMed1994

New perioral arterial flaps: anatomic study and clinical application.

We studied the vascular anatomy of the perioral region by dissecting fresh cadavers. The anatomy of perioral branches of the facial artery consistently confirmed the existence of a septal branch and an alar branch to the upper lip and a vertical labiomental branch to the lower lip. New regional flaps supplied by these perioral arterial branches are proposed in this paper. The mucosal flap from the upper lip supplied by the deep septal branch or the alar branch of facial artery can be used to restore lower lip defects. A composite flap from the lower lip supplied by the vertical labiomental branch of the facial artery can be used safely to restore combined defects of the upper lip and nose or partial defects of the lower lip.

Adult↗
PubMed1993

Microvascular transplant of the gastrocnemius muscle in rats.

The rat gastrocnemius muscle can serve as a vascularized, innervated muscle transplant model. To establish the anatomic and technical details of this model, we performed ten gastrocnemius transplants and collected data on muscle weight, dimension, and vessel caliber from each muscle. The muscle, consisting of medial and lateral heads, is supplied by pairs of sural vessels averaging 0.2 mm in diameter. These vessels, however, can be taken in continuity with the femoral vessels (averaging 1.0-1.6 mm in diameter), which are used for transplantation. The muscles weighed an average of 2.8 g, and the average pedicle length was 24 mm. Eight of ten transplanted muscles were viable with intact circulation at 72 hr. The gastrocnemius transplant was technically reliable, and the muscle bulk and contour could allow biochemical and functional studies. Donor site morbidity limits this model to transplantation studies.

Animals↗
PubMed1993

Microvascular transfer of the rectus abdominis muscle and myocutaneous flap in rats.

A rat microvascular free rectus myocutaneous flap model with a superior epigastric vessel pedicle is presented. The rectus muscle has a predictable "flow-through" axial vascular system consisting of superior and inferior epigastric vessels anastomosing under the fascial sheath, and six to seven musculocutaneous perforating branches to the skin. The superior epigastric artery and vein, averaging 0.45 mm and 0.5 mm in diameter, can be used as the vascular pedicle in muscle or myocutaneous flap transplantation. Eight muscle and 15 myocutaneous flaps were transplanted to the groin. The myocutaneous flaps averaged 3.5 cm by 1.2 cm in size; the pedicle length averaged 11 mm. The 5 day survival was 100% for muscle flaps and 67% for myocutaneous flaps. The rectus myocutaneous flap is believed to be the first true myocutaneous model in the rat.

Abdominal Muscles↗
PubMed1993

Salvage of wounds following failed tissue transplantation.

During the past 20 years, 972 microvascular transplantations have been performed for 783 patients, with an overall failure rate of 6.2 percent. Fifty-four of the 60 failed transplantations were available for long-term follow-up and were retrospectively reviewed with respect to the original indications for transplantation, the number, and the type of salvage procedures performed following transplant failure. This study illustrates that the choice of salvage procedures performed following transplant failure depends on the original indications, the location, and the severity of the resultant wound. Failure following transplantation for coverage of contour defects or unstable wounds can often be managed by non-microsurgical methods. In contrast, when the indications for transplantation included the transfer of specialized tissues for thumb or digit reconstruction, the restoration of motor or sensory function, or the coverage of a limb-threatening wound, requirements for reconstruction could be satisfied only by a second successful tissue transplant. Eighteen of the 54 cases underwent an additional transplantation, with an 89 percent success rate.

Adolescent↗
PubMed1993

Management of chronic achilles tendon infection with musculotendinous gracilis interposition free-flap coverage.

Management of infected Achilles tendon repair poses a significant reconstructive problem. Thorough debridement is most important and resection of non-viable tendon substance is required. Reconstruction of such tendon defects requires vascularized soft-tissue coverage that is stable and that offers the possibility of functional restoration. Gracilis free-tissue transfer is an effective means of providing stable, durable, well-vascularized, soft-tissue coverage in an infected Achilles tendon repair. The microsurgical anastomoses are technically straightforward. Cybex II dynomometer measurements, performed 6 months following free-tissue transplantation, revealed strength (torque) and power, at an angular velocity of 45 degrees per second, of: 59 percent and 52 percent, respectively, compared to the uninjured side. Endurance was assessed at an angular velocity of 120 degrees per second over a 15-second test interval, and was noted to be 81 percent, compared to the normal ankle. Excellent functional results and acceptable soft-tissue contour can be expected with this technique.

Achilles Tendon↗
PubMed1993

Unrecognized injuries in patients referred for emergency microsurgery.

Replantation of amputated parts and emergency microvascular repair of injured extremities are the two most common applications of clinical microsurgery. A major complication of emergency referral of such cases is the existence of the other injuries unrecognized at the time of initial evaluation. We have reviewed this complication within a series of emergency microsurgical cases referred to this unit. Several reports examining this problem of missed injuries exist in the general trauma literature. To our knowledge this study is the first to look at this important problem in the context of acutely injured patients referred for emergency microsurgery. A retrospective analysis of patients referred to Davies Medical Center over a 7-year period was performed. Nine of 1100 patients (0.8%) transferred to our unit for microsurgical evaluation and treatment had unrecognized coexisting injuries that put those patients at high risk for injury-specific morbidity and demanded immediate changes in the original care planned at the time of referral. Brief case histories of these patients are outlined. We review the trauma literature of such injuries. A concise protocol elucidating the guidelines and pitfalls of emergency microsurgical referral is offered.

Adolescent↗
PubMed1992

Aeromonas hydrophila infections following use of medicinal leeches in replantation and flap surgery.

Aeromonas hydrophila infections are a recognized complication of postoperative leech application, and can occur with measurable frequency in populations of patients treated with leeches. We review 11 previously reported leech-related Aeromonas infections and analyze seven unreported cases. These infections range from minor wound complications to extensive tissue loss and sepsis. Often, these infections followed leech application to tissue with questionable arterial perfusion. Onset of clinical infection in these patients ranged from within 24 hours of leech application to 10 days or more after leech application. Late infections may represent bacterial invasion from colonized necrotic tissue. Based on these observations, we recommend that leech applications be restricted to tissue with arterial perfusion to minimize contamination of necrotic tissue. We also recommend that patients treated with leeches receive antibiotics effective against Aeromonas hydrophila before leech application. Patients treated with leeches and discharged with eschars or open wounds might benefit from oral antibiotic therapy until wound closure. These precautions may minimize or eliminate this complication of leech use.

Adolescent↗
PubMed1992

Postprandial Aeromonas hydrophila cultures and antibiotic levels of enteric aspirates from medicinal leeches applied to patients receiving antibiotics.

Increasing use of medicinal leeches has been accompanied by increasing numbers of reports of Aeromonas hydrophila infections after leech application on or near damaged tissue. We examined the enteric contents of postprandial leeches after their application to patients receiving antibiotics. We found measurable levels of antibiotic in the leech enteric contents, and in leeches applied to patients receiving an antibiotic effective against Aeromonas hydrophila, there was a significant decrease in positive Aeromonas enteric cultures. Suppression of leech enteric bacteria by antibiotic administration to the patient may be an effective strategy to prevent invasive infection by Aeromonas hydrophila as well as bacterial colonization of devitalized tissue that could be the source of late infection. Clinical studies will be required to clarify whether suppression of leech enteric flora results in a decrease in infections associated with leech use.

Aeromonas hydrophila↗
PubMed1992

Arterial supply of the anterior ear.

Twenty cadaver auricles were injected with a latex solution to define the arterial supply of the anteroauricular surface. Two arterial networks exist, the network of the triangular fossa-scapha and the network of the concha. Both eventually communicate on the anthelix. The triangular fossa-scapha network originates from one subbranch of the upper auricular branch of the superficial temporal artery and from branches of the posterior auricular artery that come through the earlobe and triangular fossa and over the helical margin. The conchal network is provided by two to four perforators that come from the posterior auricular artery, piercing the conchal floor. Auricular branches of the superficial temporal artery in the preauricular region and their communications with the posterior auricular artery also were confirmed. We believe that a greater understanding of the detailed arterial anatomy in this area allows one to develop safely a variety of surgical techniques for reconstruction of the ear.

Arteries↗
PubMed1992

Improved salvage of complicated microvascular transplants monitored with quantitative fluorometry.

Quantitative fluorometry has been used to monitor circulation in transplanted toes and cutaneous flaps in our unit since 1982. Analysis of 177 uncomplicated transplants monitored by quantitative fluorometry shows that this technique has low false indication rates for arterial occlusion (0.6 percent of patients) and venous occlusion (6.2 percent of patients). None of these patients was reexplored because of a false monitor reading, and except for single abnormal sequences, monitoring appropriately indicated intact circulation throughout the postoperative period. Quantitative fluorometry has correctly indicated vascular complications in 21 (91.3 percent) of 23 transplants over an 8-year period. The salvage rate (85.7 percent) of the fluorescein-monitored reexplored transplants was significantly higher than the salvage rates of similar reexplored transplants not monitored with fluorescein and of reexplored muscle flaps (which cannot be monitored with the fluorometer used at this unit). These clinical data indicate that quantitative fluorometry is a valid and useful postoperative monitor for transplanted toes and cutaneous flaps.

Fluorometry↗
PubMed1992

Hand reconstruction with partial toe and multiple toe transplants.

Microsurgical transplantation of toes to the hand can serve as an excellent method of reconstructing the severely traumatized hand. This article reviews the authors' experience with 188 great-toe and second-toe transplants. Detailed operative sequence and postoperative care are also discussed.

Finger Injuries↗
PubMed1992

Muscle flap monitoring in a rat model with a variable gain quantitative fluorometer.

A variable gain dermofluorometer with a wide range of sensitivities capable of quantifying fluorescein emission from both skin and muscle was tested in a rat latissimus dorsi island muscle flap model. Quantitative fluorometric readings directly from muscle and skin sites that did not undergo surgery were taken at intervals over 2 hours after intravenous fluorescein injection. Muscle flaps with intact pedicles gave an inflow-outflow pattern. A no-outflow pattern was seen in muscle flaps with ligated pedicle veins and a no-inflow pattern was seen in muscle flaps with ligated pedicle arteries. These patterns were similar to the flow pattern seen with quantitative fluorometric monitoring in flaps with cutaneous components. These results suggest that quantitative fluorometry may be applicable to circulation monitoring in muscle flaps.

Animals↗
PubMed1991

Microvascular transfer of anterior and posterior gracilis muscles in rats.

A microvascular free muscle flap in rats using the anterior and posterior gracilis muscles with femoral vessels as its pedicle is presented. The gracilis muscles form a single unit supplied by the muscular branch artery and vein, averaging 0.3 mm and 0.4 mm in diameter, respectively. These small sizes preclude their use in transplantation. However, the muscular branch vessels in continuity with the femoral vessels can be used for the vascular pedicle in this muscle transplant. This muscle flap was transplanted to the contralateral femoral vessels by end-to-end anastomosis in 15 rats. Thirteen animals survived and 11 flaps were viable at 3 days for a success rate of 85%. The gracilis flaps averaged 674 mg in weight, 1.87 cm X 1.36 cm in size, and 7.23 mm in pedicle length. This free muscle flap model is reliable, relatively easy to perform, and provides adequate muscle bulk for pharmacologic and biochemical studies in transplanted muscle. No lower extremity complications were noted following femoral vessel ligations.

Anastomosis, Surgical↗
PubMed1991

Sequential multiple free flap transfers for reconstruction of devastating hand injuries.

Restoring function to a severely damaged hand can require complex reconstructions using multiple tissue transfers to replace skeletal, soft tissue, and nerve components. We present 2 patients with severe hand trauma treated with serial multiple flap transfers, an operative sequence not previously reported in detail. One patient underwent five flap transfers in three operations, whereas the second patient underwent four flap transfers in two operations. All the flaps survived. Total anesthesia time for these patients was 43.5 and 34.5 hours, respectively. Both patients obtained measurable functional restoration, and suffered no significant perioperative morbidity. These patients illustrate the clinical feasibility of serial multiple microvascular transplantations for complicated reconstructions.

Adult↗