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R D Acland

Publications and source records attributed to R D Acland.

At least 19 recordsLinked to original sources
PubMed1994

Comparison of the effects of commonly used wound agents on epithelialization and neovascularization.

BACKGROUND: The primary effect sought with most topical wound therapy is antimicrobial. Topical wound agents are thought to promote normal healing by protecting the wound from infection. In this study, we examined the effect of six commonly used topical wound agents (bacitracin, sodium hypochlorite, silver nitrate, silver sulfadiazine, mafenide acetate, and povidone-iodine) on epithelialization and neovascularization in noninfected wounds. For this study, a new wound model was used in which direct visualization and quantification of wound epithelialization and neovascularization were carried out throughout the entire healing process. STUDY DESIGN: We measured the effect which 500 U per g of bacitracin, 0.25 percent of sodium hypochlorite, 0.5 percent silver nitrate, 1 percent silver sulfadiazine, 8.5 percent mafenide acetate, and 10 percent povodione-iodine had on the rate of wound epithelialization and neovascularization. The agents were applied topically to 99 circular full-thickness wounds (2.25 mm diameter, 0.125 mm depth) created on the dorsum of male hairless mouse ears. This model enabled us to visualize and measure directly wound epithelialization and neovascularization repeatedly throughout healing, using intravital video microscopy and computerized digitized planimetry. RESULTS: Control wounds and wounds treated with silver sulfadiazine (n = 18) and mafenide acetate (n = 14) epithelialized in 7.2 +/- 0.7, 7.1 +/- 0.3, and 7.3 +/- 0.3 days, respectively. This was significantly (p < 0.01) faster than the wounds treated with povidone-iodine (n = 10), sodium hypochlorite, (n = 8), and bacitracin (n = 13). Wounds treated with povidone-iodine epithelialized the slowest (11.8 +/- 0.55 days). Wound neovascularization was completed most rapidly in the groups treated with povidone-iodine and silver sulfadiazine (15.0 +/- 0.4 and 15.3 +/- 0.7 days, respectively). This was significantly (p < 0.05) faster than wounds treated with silver nitrate (n = 15), which neovascularized in 18.4 +/- 0.56 days. One-half of the wounds treated with sodium hypochlorite (eight of 16) did not epithelialize or neovascularize. CONCLUSIONS: The various antimicrobial agents studied in our in vivo model affect wound epithelialization and neovascularization differently. These effects on these two very important aspects of healing should be taken into consideration when indicating a specific agent for treatment of different types of wounds.

Animals↗
PubMed1992

An extended approach for the vascular pedicle of the lateral arm free flap.

We present an extension of the surgical approach for harvesting the lateral upper arm free flap by which an additional 6 to 8 cm of pedicle length may be gained. First, the flap is raised by the standard lateral approach. Then, by proceeding proximally and posteriorly, the triceps muscle is split between its lateral and long heads to expose the entire length of the profunda brachii vessels in the spiral groove. A tunnel is developed beneath the lateral head of the triceps, and the flap or its pedicle is delivered through this. We describe the surgical technique and present details of a dissection study on 25 fresh cadaver limbs. The nerve branches to the lateral head of the triceps, which are close to the vessels of the flap, are highly variable in number and location. When unusually short and distally placed, they are at risk of damage, but damage can be avoided if the tunnel is not unduly widened. We present our early clinical experience in 10 consecutive cases using the extended-pedicle lateral arm flap. The free pedicle length in this series ranged from 8 to 13 cm. The maximum flap size was 5 x 19 cm. All cases were successful, although one required reoperation for venous thrombosis. Although postoperative testing of upper arm muscle function showed some weakness and impaired endurance, this was found equally in the surgically disturbed triceps and in the untouched elbow flexors and thus could not be attributed to motor nerve damage to the triceps muscle.

Adolescent↗
PubMed1992

Microsurgical adjuncts in salvage of the ischemic and diabetic lower extremity.

Revascularization of distal occlusive disease in the diabetic has been markedly enhanced by microsurgical techniques. Extremely small, heavily calcified vessels are able to be reliably reconstructed using microsurgical techniques and high magnification. Additionally, revascularization followed by microsurgical free tissue transfer has proven to be a valuable alternative to amputation in patients with major soft-tissue loss, or bony or tendon lesions requiring soft-tissue reconstruction. Although metabolic risks are potentially high, we have experienced a very low morbidity and mortality with a thorough medical work-up and follow-through in conjunction with these major procedures. It is our expectation that judicious application of microsurgical techniques in treatment of the ischemic diabetic lower extremity will continue to improve the chances for long-term bipedal ambulation in this patient population.

Adolescent↗
PubMed1992

Microcirculatory disturbances following the passage of emboli in an experimental free-flap model.

Following completion of arterial repair in an experimental free-flap model, platelet emboli have been observed passing through the microcirculation downstream. The purpose of this experimental study was to observe and quantitate changes in capillary perfusion occurring subsequent to these events. The isolated rat cremaster model was used. For 6 hours subsequent to surgical injury of the main artery in this model, the number of emboli and the number of perfused capillaries downstream were counted. In eight rats having an intentional arterial wall injury, emboli were consistently seen during the first hour of reflow. In the nine control animals having no arterial injury, no emboli were seen. The presence of emboli in the cremaster muscle, resulting from the arterial injury, was associated with a significant reduction in the number of perfused capillaries. We suggest that the observed decrease in capillary perfusion was associated with microemboli that produced an adverse effect for several hours after their initial presence in the circulation.

Analysis of Variance↗
PubMed1990

Refinements in lower extremity free flap surgery.

This chapter recommends numerous factors that are significant refinements in approach and execution of lower extremity free flaps. I encourage a clear conceptual separation between the two essential phases of successful reconstruction of problem wounds: wound preparation and flap transfer. I have found that antibiotic beads maintain the sterility of temporary bony dead space. Due emphasis should be given to preparation of the surgeon, patient, and wound, allowing a nonemergency approach to lower extremity free flap coverage. The surgeon needs to be familiar with a variety of flaps beyond the usual workhorse group. Also, attention should be paid to perioperative warmth and hydration, and vessels affected by posttraumatic vessel disease must be avoided. A positive attitude toward the use of vein grafts whenever necessary is important. I also favor careful planning of the exact size and shape of the flap and length of the vessels along with use of a widely spatulated technique of end-to-side anastomoses.

Anti-Bacterial Agents↗
PubMed1989

Direct in vivo observations of embolic events in the microcirculation distal to a small-vessel anastomosis.

This study was done to determine whether microemboli are produced by an arterial anastomosis. Direct in vivo observations were made in an isolated microcirculatory bed lying directly downstream from a newly made anastomosis. The tissue used was the isolated rat cremaster muscle, a new experimental model. The vessel anastomosed was the external iliac artery. Following anastomosis, microemboli were clearly observed in eight of eight animals during the first 30 minutes after clamp release. Embolic events were sometimes of impressive magnitude and in one case were associated with cessation of blood flow throughout the preparation. No microemboli were observed in eight of eight animals subjected only to dissection of the cremaster, nor were any observed in eight of eight animals in which the isolated cremaster was subjected only to 2 hours of clamp ischemia. These findings may be significant in explaining perturbations to blood flow following free-tissue transfer and instances of partial tissue necrosis following apparently successful arterial repair. These findings also identify an important factor (microemboli) to be considered in research on reperfusion injury.

Animals↗
PubMed1988

Vascular isolation of the rat cremaster muscle.

The vascular supply to the rat cremaster muscle was completely isolated to provide a microvascular preparation with a controllable blood flow. The anatomy of the cremaster vascular supply and the surgical approach to isolate the cremaster muscle on its neurovascular pedicle are described. The functional integrity of this isolated cremaster preparation was tested using intravital video microscopy to evaluate the tissue's response to vasoactive agents and to peripheral nerve stimulation. The isolated cremaster muscle was positioned in situ in a controlled tissue bath and concentration response curves to the topical application of norepinephrine (NE) and acetylcholine (Ach) were determined. Vasoconstriction elicited by the topical application of NE or by stimulation of the genitofemoral nerve trunk was similar for both the isolated and standard cremaster preparations. Application of 10(-5) M Ach caused maximal vasodilation equal to that produced by 10(-3) M papaverine in both preparations. In summary, the isolated cremaster muscle of the rat is an acceptable model of a skeletal muscle microcirculation which can be used to investigate microvascular function when precise monitoring or control of perfusion to the entire muscle is needed.

Acetylcholine↗
PubMed1986

Microvascular reconstruction after electrical and deep thermal injury.

Six cases are presented demonstrating uncomplicated primary healing following early microvascular reconstruction for complex electrical and deep thermal injuries. We advocate early preservation of eschar and the prevention of infection with the use of penetrating topical antibacterial agents, removal of the soft-tissue eschar when clinically indicated, and immediate coverage of the undebrided bone through the provision of well-vascularized tissue. Microvascular free tissue transfer should be considered as a primary method of reconstruction for complex electrical or thermal injury whenever clinically feasible. These reconstructive techniques offer an early, reliable means of definitive reconstruction, preserving function, providing uncomplicated healing, and promoting early rehabilitation.

Adult↗
PubMed1986

Surgical anatomy and blood supply of the fascial layers of the temporal region.

In 15 fresh cadavers (30 sides), we studied the two layers of fascia in the temporal region, with particular regard to their blood supply and to their usefulness--together or separately--as microvascular free-tissue autografts. The superficial temporal fascia (temporoparietal fascia, epicranial aponeurosis) lies immediately deep to the hair follicles. It is part of the subcutaneous musculoaponeurotic system and is continuous in all directions with other structures belonging to that layer--including the galea above and the SMAS layer of the face below. The deep temporal fascia (temporalis fascia, investing fascia of temporalis) is separated from the superficial fascia by an avascular plane of loose areolar tissue. It completely invests the superficial aspect of the temporalis muscle down to (but not beyond) the zygomatic arch. It is firmly attached to periosteum all around the margin of the muscles. Below it is attached to the upper border of the zygomatic arch. We found the deep temporal fascia to be supplied solely by the middle temporal artery, a constant branch of the superficial temporal. The middle temporal artery arises 1 to 3 cm below the upper border of the zygomatic arch, runs always superficial to the arch, and enters the deep temporal fascia immediately above that layer's attachment to the zygomatic arch. If the middle temporal vessels are protected, the two layers of temporal fascia can be raised together as a fully vascularized tissue island. This island can be fashioned as a bilobed or a double-layered flap, depending on the manner of dissection. The potential surgical usefulness of these findings is discussed.

Adult↗
PubMed1985

Mandibular reconstruction with microvascular bone transfer. Series of 10 patients.

Mandibular reconstruction with microvascular bone transfer was carried out in 10 patients, including 8 with far advanced intraoral carcinoma and 2 with posttraumatic facial and mandibular defects. Eight patients presented with compromised defects as a result of radiation injury, infection, and scarring. Nine patients experienced primary bony union with complete functional and esthetic reconstruction of the mandible, and two patients eventually received dentures. This technique has resulted in a more effective, more reliable, and earlier reconstruction compared with conventional methods.

Adult↗
PubMed1985

Monitoring free vascularised jejunum grafts.

A reliable method of monitoring free vascularised jejunum to the head and neck region has been used in six patients. Preliminarily, the jejunum island flap is subdivided into major and minor segments. Transferred to the neck, the major part is used to reconstruct the oesophageal or pharyngeal defect, while the minor part supplied by the same segmental mesenteric artery is exteriorised through the neck incision. After five days direct monitoring, the marker segment is clamped, tied and excised before suturing the neck wound under local anaesthesia. No failures of the graft occurred. The effectiveness of this technique has surpassed all previously published and unpublished methods.

Aged↗
PubMed1985

Distal revascularization and microvascular free tissue transfer: an alternative to amputation in ischemic lesions of the lower extremity.

Most lower extremity amputations result from complications of diabetes and arterio-sclerotic occlusive diseases below the inguinal ligament. Improved limb salvage has been achieved by an aggressive approach to distal revascularization in the severely ischemic lower extremity. There remains, however, a high incidence of amputation resulting from progression of the ulceration or gangrene into deeper and less well-vascularized tissues, such as tendon and bone. Even in the nonischemic extremity, such wounds rarely heal without flap coverage. Microvascular free tissue transfers promote healing by providing coverage with healthy, nondiseased, well-vascularized tissue for these difficult defects. Successful free flap transfer requires a high-pressure recipient inflow vessel. In contrast to individuals with nonarteriosclerotic lesions, many individuals with nonhealing ischemic lesions have no acceptable artery demonstrated on high-resolution angiography to serve as a recipient vessel. Limb salvage has been achieved in four candidates for amputation utilizing distal revascularization followed by free tissue transfer coverage of the ischemic lower leg defects.

Aged↗
PubMed1985

Experience with the temporoparietal fascial free flap.

The temporoparietal fascia is an ideal tissue source for free transfer to distant sites where ultrathin coverage is either desirable or mandatory. The fascia's dependable vascular anatomy facilitates the technical aspects of microvascular transfer by means of its large vessels, ample pedicle, and ability to be grafted on either side. Furthermore, this highly vascular tissue is available in surprisingly large quantities, and its donor scar is hidden in the hair. The authors have found this flap useful (1) in covering exposed bone and tendon without adding unwanted bulk, (2) in providing thin flap coverage or lining in major facial reconstruction, (3) in covering vital structures such as exposed nerves and vessels, (4) in providing neovascularity both as a recipient graft bed and for control of chronic infection, and (5) in reestablishing gliding-tendon mechanisms. The authors have successfully employed this free flap in 15 cases which involved deformities of the ankle, foot, Achilles tendon, forearm, hand, nose, and contralateral ear and scalp. Seven cases are utilized to illustrate the broad application of this unique and versatile free flap.

Achilles Tendon↗
PubMed1984

Managing the outer limits of reconstruction with microsurgical free tissue transfer.

Six patients had major deficits reconstructed with microsurgical free tissue transfer. In contrast to some opinions that free tissue transfer is a "method of last resort," these patients were selected for microsurgical reconstruction as a method of first choice due to the qualities desired in the reconstruction, the reliability of the technique, and the desire to minimize the functional or aesthetic deficit at the donor site. Microsurgical techniques allowed a reconstruction in these cases that would have been difficult or impossible by conventional techniques, while they markedly improved the quality and reliability of the reconstruction and decreased the donor morbidity. Microsurgical free tissue transfer has been reported to have a success rate of 94% in centers where a significant volume of surgery is done. We believe the continued refinement of microsurgical techniques and their increased application will improve the results of reconstruction in a large category of severe traumatic and cancer defects.

Adult↗