Biomedical subjects
Publications and source records attributed to G A Dumanian.
Three cases of congenital arteriovenous malformations localized to the flexor digitorum superficialis presented to a single surgeon. In all three cases, the tumours were resectable with negligible morbidity to the upper extremity.
A novel method for the control of a myoelectric upper limb prosthesis was achieved in a patient with bilateral amputations at the shoulder disarticulation level. Four independently controlled nerve-muscle units were created by surgically anastomosing residual brachial plexus nerves to dissected and divided aspects of the pectoralis major and minor muscles. The musculocutaneous nerve was anastomosed to the upper pectoralis major; the median nerve was transferred to the middle pectoralis major region; the radial nerve was anastomosed to the lower pectoralis major region; and the ulnar nerve was transferred to the pectoralis minor muscle which was moved out to the lateral chest wall. After five months, three nerve-muscle units were successful (the musculocutaneous, median and radial nerves) in that a contraction could be seen, felt and a surface electromyogram (EMG) could be recorded. Sensory reinnervation also occurred on the chest in an area where the subcutaneous fat was removed. The patient was fitted with a new myoelectric prosthesis using the targeted muscle reinnervation. The patient could simultaneously control two degrees-of-freedom with the experimental prosthesis, the elbow and either the terminal device or wrist. Objective testing showed a doubling of blocks moved with a box and blocks test and a 26% increase in speed with a clothes pin moving test. Subjectively the patient clearly preferred the new prosthesis. He reported that it was easier and faster to use, and felt more natural.
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BACKGROUND: We propose a simple algorithm for management of patients with challenging abdominal fascial defects. METHODS: The medical records of 64 patients with complicated abdominal wall defects representing a consecutive series by a single surgeon over a 4-year period were reviewed. Group I patients presented with massive fascial defects and closed wounds. They were reconstructed with autogenous tissue using either the separation of parts (SOP) procedure or free tensor fascia lata (TFL) grafts. Group 2 patients had fascial defects with open wounds. Wound closure was first accomplished with either STSG or primary skin closure over viscera. These patients, now "converted" into patients with closed wounds, were reconstructed months later as in group 1. RESULTS: Average defect size was 320 cm2. Wound closure was achieved in one procedure in all patients with open wounds. Time to discharge after this procedure averaged 9 days. The only morbidity of wound closure was skin graft donor site pain. Average time from temporary staged closure with skin grafts to definitive closure with autogenous tissue was 5 months. Repair of closed fascial defects with autogenous tissue was performed in 51 patients. Average time to discharge after autogenous tissue repair was 6.6 days. Recurrence of hernia was noted in 2 (3.9%) patients with an average follow-up of 24 months. CONCLUSIONS: Treatment of challenging abdominal wall defects can be accomplished simply and safely utilizing the above surgical algorithm. Open wounds are converted into closed wounds and fascial defects are repaired with autogenous tissue. This treatment plan has proved to be effective in a wide variety of situations.
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Although tourniquets play an integral role in extremity surgery, no clear guidelines exist for the use of tourniquets in microsurgery. We undertook a study in 12 healthy volunteers to better understand the coagulation properties of blood distal to an inflated tourniquet. At a 15-min inflation time, blood distal to an inflated tourniquet clots faster than blood taken from the opposite arm after addition of exogenous thrombin (12.5 s vs 17.5 s, P < 0.0001). Neither fibrinopeptide A (FPA) levels nor tissue plasminogen activator (tPA) levels were different from those of controls. Tissue factor pathway inhibitor (TFPI), an endogenous local anticoagulant, was slightly but significantly elevated in tourniquet blood. Although much remains to be understood, we believe that microvascular surgery in a bloodless field is safe and efficacious. Nine patients are presented who successfully underwent microvascular surgery in a bloodless field, using various types of extremity tourniquets.
The basic principles of successful wound closure remain the same: careful preoperative evaluation, removal of underlying nonviable tissue, and well-vascularized soft-tissue coverage. Many complex or "hostile" back wound closures also require stabilization of the spine and a two-layered wound closure. The use of long arteriovenous fistulas with free tissue transfer provides an additional weapon for the treatment of these complex wounds.
PURPOSE: Lower-extremity arterial anatomy that is insufficient for successful vein bypass grafting and major proximal foot wounds often lead to leg amputation in patients with severe ischemia. Free tissue transfer, which can provide limb salvage in these patients after arterial reconstruction, was studied. METHODS: During a 45-month period, 21 patients who otherwise would have undergone leg amputation were treated with arterial bypass by means of vein grafting and free tissue transfer. Ages of the patients ranged from 40 to 73 years (average, 59 years); 18 of the 21 patients had diabetes mellitus; and all patients except one were men. Arterial reconstruction was performed from the femoral (nine of 21 patients) or popliteal artery (12 of 21 patients) to the posterior tibial (eight patients), dorsalis pedis (five patients), peroneal (three patients), popliteal (one patient), or anterior tibial artery (one patient), or directly to the free flap (three patients). The tissue transferred included latissimus dorsi (five patients), rectus abdominus (five patients), omentum (five patients), gracilis (two patients), radial forearm flaps (three patients), and a scapular flap (one patient). Foot defects were debrided, including the appropriate toe or transmetatarsal amputation, covered with the transferred flap, and then split-thickness skin grafted. Arterial flow for all flaps was through the vein grafts, with direct arterial anastomosis and with venous outflow through adjacent tibial veins. RESULTS: All 21 procedures were successful initially, without operative mortality, but three failed within 4 weeks because of uncontrolled infection (two) or embolization from a remote site (one) and required below-knee amputation. Grafts remained patent in 18 procedures, and follow-up of this cohort ranged from 1 to 45 months (mean, 13.3 months). Two patients died, one after 4 months and one after 6 months, of unrelated illness; at the time of death, they had functioning grafts. The remaining 19 patients are alive. Of these, 15 have patent arterial grafts, all viable free flaps. Thus, limb salvage was accomplished in 18 of 21 (86%) patients who otherwise would have required below-knee amputation. CONCLUSION: Patients destined for leg amputation despite aggressive traditional arterial bypass grafting methods can achieve limb salvage with the additional technique of free tissue transfer.
We developed a new quantitative rat sciatic nerve model to test whether free fat grafts can reduce postoperative perineural scar formation. Epineurectomies of sciatic nerves were performed to create scar. The force required to distract the nerve a unit distance was measured after surgery to determine the time of maximal scar formation. Nerve stiffness normalized for rat weight was statistically greater at 2 months after the initial dissection (0.097+/-0.009 g/mm/g rat weight; n = 10 limbs) than rat limbs that had not undergone a previous dissection (0.075+/-0.012 g/mm/g rat weight). Perineural scar thickness was thicker at 2 months than the perineural tissue in preoperative controls. Free fat grafts decreased nerve stiffness at 2 months (0.078+/-0.012 g/mm/g rat weight) in comparison to the contralateral surgical control limb without a fat graft (0.094+/-0.014 g/mm/g rat weight). Free fat grafts reduced the strength of postoperative perineural scar in this surgical model; however, they were associated with an unexpected finding of substantial postoperative neuropathy.
Primary invasive Aspergillus Infection of the soft tissue is rare and typically affects immunocompromised patients in several distinct patterns of clinical presentation. In general, the role of surgery in the treatment of this disease is the removal of infected or necrotic tissue to prevent dissemination and mortality. However, the specific surgical recommendations have varied widely among reports due to the varied clinical circumstances in each series. The authors present the case of a patient with a primary invasive Aspergillus infection. They review the reported surgical experience with this disease, and discuss outcomes and surgical approaches in the context of several variations in clinical presentation. In all situations, antifungal therapy and prompt surgical intervention are critical in treating these initially localized but potentially lethal infections. The extent of intervention can range from minor debridement to amputation, and is based on the presence of persistent immunocompromise, the presence and extent of tissue necrosis, and the rate of progression during antifungal therapy.
BACKGROUND: Patient selection criteria have not been clearly established for use of the radial artery as a bypass conduit. To help establish such criteria, we measured changes in digital blood flow and hand function after radial artery removal. METHODS: Ninety-eight patients of the first 122 consecutive patients considered for radial artery harvest met predetermined criteria by vascular noninvasive studies to undergo removal of the radial artery. In 42 of these 98 patients, the radial artery was actually used as a bypass conduit; 28 of these 42 patients returned for noninvasive vascular studies, a critical review of hand function, and a hand symptom questionnaire. RESULTS: There were no significant differences between the operated and nonoperated hands for digital-brachial indices, cold response, grip or pinch strength, digital two-point discrimination, or nine-hole peg tests. The patients had an increased incidence of a small amount of forearm numbness and tingling, but no increase of pain or cold intolerance. CONCLUSIONS: For properly selected patients, there are minimal changes in hand function after radial artery removal.
Necrotizing fasciitis is a destructive soft tissue infection that is most typically caused by group A streptococci or a combination of facultative and anaerobic bacteria. Patients at risk for the development of necrotizing fasciitis often have compromised immune function or poor tissue perfusion. This report describes a case of necrotizing fasciitis caused by Cryptococcus neoformans, a pathogen not previously associated with this primary destructive soft tissue infection. The process occurred in a patient at risk for the development of opportunistic infection. We briefly review the risk factors for the development of necrotizing fasciitis and the typical bacteriologic findings. Cryptococcal infections and their treatment are described. Despite the uncommon pathogen, the treatment of this patient followed established principles-prompt surgical intervention and systemic antimicrobial therapy tailored to the offending organisms.
The vascular noninvasive studies of 289 consecutive cardiac surgery patients were reviewed to better understand hand blood-flow physiology in an older population with vascular disease. The radial artery was found to be more important to pulsatile digital blood flow than the ulnar artery. In more than 20 percent of hands, the thumb and the index and fifth fingers lost pulsatile blood flow with radial artery compression at the wrist compared with only 5 percent with ulnar artery compression. The maintenance of pulsatile digital blood flow did not follow anatomic patterns of blood vessels previously presumed to be of paramount importance. The hand acts more like a single vascular bed than it does like two separate systems with a connecting arch.
The surgically created vascular anastomosis is a thrombogenic zone of uncertain etiology. This study was designed to investigate the importance of tissue factor as a cause of human microvascular thrombogenicity. The ability of tissue factor pathway inhibitor (TFPI) to block the effect of tissue factor was also tested in this whole-vessel model system. Tissue factor activity in the presence of absence of TFPI was assayed on the luminal surface of dissected human placental arteries, on the advential surface, and also at the site of a microvascular anastomosis. Vessel wall thrombin activity was measured in the presence and absence of TFPI. Platelet deposition onto a vessel surface using a perfusion system was measured with and without TFPI. Tissue factor activity was greater on the adventitia (4.6 +/- 2.8 x 10(-4) units factor Xa generated/min) than on the endothelium (1.8 +/- 1.6 x 10(-4), P < 0.03) or at a surgically created anastomosis (2.1 +/- 1.2 x 10(-4), P < 0.04). TFPI reduced Xa generation to undetectable levels in 21 of 23 endothelial, adventitial, and anastomotic segments (P < 0.002). TFPI significantly reduced vessel wall thrombin activity in comparison to control anastomoses (control, 3.2 +/- 1.7 ng fibrinopeptide A (FPA)/(ml x min); TFPI, 1.4 +/- 1.2 ng FPA/(ml x min); P < 0.0001). TFPI reduced the platelet deposition on vessel segments with intact endothelium (no TFPI, 0.88 +/- 0.69 x 10(6) platelets/cm2; TFPI, 0.49 +/- 0.29 x 10(6) platelets/cm2; P < 0.06) and on vessel segments with anastomoses (no TFPI, 1.3 +/- 0.70 x 10(6) platelets/cm2; TFPI, 0.76 +/- 0.35 x 10(6) platelets/cm2; P < 0.02). This study demonstrates the importance of tissue factor as a thrombogenic element in a human whole-vessel model system. TFPI is effective in reducing this thrombogenicity.
BACKGROUND: Abdominal wall dehiscence with an associated enterocutaneous fistula is a surgical complication with high morbidity and mortality. Management of the abdominal wall defect is complicated by the continued emergence of liquid bowel contents. PATIENTS AND METHODS: Large abdominal wall wounds of 10 patients with postoperative abdominal wall dehiscence and active enterocutaneous fistulae were managed with early skin grafting directly onto the granulated abdominal viscera. RESULTS: Skin graft take averaged 93 +/- 12%, and there were no perioperative complications related to the skin grafting procedure. Overall mortality was 1 out of 10 patients. Enterocutaneous fistula output did not prove overly injurious to the skin grafts. Wound care was simplified in all but 1 patient with fitting of an ostomy appliance. CONCLUSION: Temporary abdominal wall wound closure with skin grafts improved patient comfort and simplified wound care in a staged reconstructive approach to this surgical complication.
We describe a simple technique to facilitate the primary closure of skin defects. Skin, subcutaneous tissue and fascia are undermined as a unit on both sides of the defect. Fascial releasing incisions are performed, creating two bipedicled fascial flaps attached to the overlying skin. The fascia is approximated, if possible, and the skin sutured. We believe this technique offers a number of advantages and results in a superior closure to that obtained with the conventional method of skin undermining. This approach has enabled the closure of 10 of 11 medium sized wounds.
The human microvascular anastomosis represents a localized environment with strongly thrombotic tendencies. In previous studies, an increase in initial platelet deposition at a human ex vivo anastomosis was measured. It is postulated that this increase in anastomotic platelet deposition was due to a reduction in anastomotic prostacyclin production as a consequence of local endothelial cell injury or loss. Instead, in this study, an increase in anastomotic prostacyclin production over unsutured controls (control 1093 +/- 222 pg/ml of 6-keto prostaglandin F (PGF) 1-alpha, n=21; anastomosis 2494 +/- 414, n=21, mean +/- 1 SEM, p=0.005) is demonstrated. Anastomotic prostacyclin production was augmented by addition of arachidonic acid (0.1 mM) (39,000 +/- 11,300 pg/ml of 6-keto PGF 1-alpha, n=7, p<0.001) and suppressed by the preincubation of vessel segments with aspirin in a dose-dependent fashion (1mM) (83+/-22 pg/ml of 6-keto PGF 1-alpha, n=21, p<0.001); aspirin (0.1 mM) (312 +/- 56 pg/ml of 6-keto PGF 1-alpha, n=7, p<0.001). In further studies using a perfusion apparatus of human blood pumped through human placental artery segments, suppression of prostacyclin production did not augment initial platelet deposition (control anastomosis 4.9 +/- 2.2 x10(6) platelets per cm2, aspirin treatment 6.0 +/- 2.8 x 10(6) platelets per cm2, n=5, mean +/- 1 SEM, p>0.05). Suppression of platelet function with aspirin (0.1 mM) also did not decrease initial platelet deposition onto the anastomosis (5.8 +/- 2.8 x 10(6) platelets per cm2, n=r, p>0.05). In this model system, initial platelet deposition at the anastomosis may not be dependent upon cyclooxygenase pathways.
The Charles procedure, named for Sir Richard Henry Havelock Charles, is an eponym for a surgical treatment of leg lymphedema. Sir Havelock led a fascinating life, with his travels taking him to India, the Afghan territories, and the Court of King George V of England. At the turn of this century, Sir Havelock published material describing a series of 140 consecutive patients treated successfully for scrotal lymphedema. In a book chapter published a decade later, entitled "Elephantiasis Scroti," Sir Havelock briefly described the treatment of leg lymphedema but did not document a single successful case report. The name of Sir Havelock Charles was absent from the literature until 1950, when Sir Archibald McIndoe attributed the treatment of leg lymphedema with radical excision and skin grafting to Sir Havelock. References to Charles for the treatment of leg lymphedema have proliferated since that time.