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Biomedical subjects

J M Malone

Publications and source records attributed to J M Malone.

At least 55 records · Page 3Linked to original sources

Gastric outlet obstruction caused by traumatic pseudoaneurysm of superior mesenteric artery.

Traumatic pseudoaneurysms of the superior mesenteric artery (SMA) are extremely rare. We describe two cases of posttraumatic proximal SMA pseudoaneurysms with symptoms of gastric outlet obstruction. Repair was accomplished by aorta-SMA bypass with saphenous vein. Injuries to the proximal SMA are easily missed at laparotomy, especially if intestinal ischemia or hematomas are absent. Recognition and repair are stressed to avoid the complications associated with pseudoaneurysm formation.

Adult↗

Porta hepatis disruption from blunt trauma.

Extrahepatic porta hepatis injuries from blunt abdominal trauma are exceedingly rare; all recently reported cases involve disruption of the common bile duct at its intrapancreatic portion. We herein report a patient with lacerations of the proper hepatic artery and bile duct occurring from deceleration/torsion of the porta hepatis after high speed vehicular collision.

Accidents, Traffic↗

Prochlorperazine and transdermal scopolamine added to a metoclopramide antiemetic regimen. A controlled comparison.

Cisplatin-induced nausea and vomiting occurs both acutely and over a prolonged period of time. These symptoms may be incapacitating and are frequently given as a reason to discontinue therapy. We compared prochlorperazine and transdermal scopolamine when added to a standardized metoclopramide antiemetic regimen. Twenty-seven patients receiving cisplatin at 100 mg/m2 were randomly assigned to one of the two treatment arms. Patients were observed during chemotherapy and answered a standard questionnaire 24-26 hours later. Among similar treatment groups no differences were seen regarding the number of emetic events, level of nausea, degree of sedation or overall acceptability of one treatment arm or another. While not superior to prochlorperazine, transdermal scopolamine is a useful antiemetic agent and can be combined with metoclopramide in an attempt to reduce cisplatin-induced nausea and vomiting. Further evaluation of this approach is needed.

Administration, Cutaneous↗

Timing of carotid endarterectomy after acute stroke.

An arbitrary delay of at least 6 weeks before performing carotid endarterectomy after acute stroke has been recommended based on anecdotal reports. This prolonged interval may increase the danger of recurrent neurologic deficit before surgery. From September 1978 to September 1988, carotid endarterectomy was performed on 140 patients at variable intervals after stroke. Eleven patients had temporary stroke, which left 129 patients with neurologic symptoms that persisted for 3 weeks or had a cortical infarct on CT scanning. A prospective therapeutic protocol was applied to 82 patients admitted with acute stroke. They were observed until neurologic recovery reached a plateau, based on clinical observation by a neurologist, before performing angiography and carotid endarterectomy (group I). Forty-seven patients were not seen until after recovery from stroke was established (group II). At initial presentation, the severity of neurologic deficit was classified as mild, moderate, or severe in 31%, 58%, and 11%, respectively. Recovery before operation was registered as complete in 11%, mild residual in 66%, moderate residual in 21%, and severe residual in 2%. Group I patients (n = 82, 64%) were operated on within 6 weeks of stroke and group II (n = 47, 36%) were operated on at varying times after 6 weeks. No significant difference was found in the incidence of cerebrovascular events (1.2% vs 4.2%) and deaths (1.3% vs 2.1%) between groups I and II with respect to the timing of carotid endarterectomy, and no significant difference was found between patients operated on at 2, 4, 6, or more than 6 weeks after stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Iatrogenic tibial pseudoaneurysm following below-knee amputation.

Tibial vessel injury during lower extremity amputation has not been reported, despite the obvious proximity of these vessels to the fibula and tibia. We present a case of acute pseudoaneurysm with arteriovenous fistula of the posterior tibial vessels following amputation, due to (unrecognized) arterial and venous injury due to fibular periosteal elevation.

Adult↗

Prevention of amputation by diabetic education.

This prospective randomized study evaluated the influence of a simple education program on the incidence of lower extremity amputation in diabetic patients. Two hundred three patients were randomized into two groups: Group 1, education (103 patients, 203 limbs) and Group 2, no education (100 patients, 193 limbs). There were no significant differences in medical management or clinical risk factors between the two groups. The amputation rate was three times higher in Group 2 (21 of 177 limbs versus 7 of 177 limbs; p less than or equal to 0.025), the ulceration rate was three times higher in Group 2 (26 of 177 limbs versus 8 of 177 limbs; p less than or equal to 0.005), and there was no difference in the overall incidence of infection (2 of 177 limbs). Overall success in Group 1 was highly significantly different from Group 2 (160 of 177 limbs versus 128 of 177 limbs; p less than or equal to 0.0005). This study demonstrated that a simple education program significantly reduced the incidence of ulcer or foot and limb amputation in diabetic patients.

Amputation, Surgical↗

Trauma malpractice claims related to trauma level designation.

The purpose of the present study was to review a one-state experience (Arizona) with trauma malpractice claims as a function of hospital trauma level designation. A total of 191 cases covering 7 years was reviewed and analyzed. Three categories of treatment facilities were compared: American College of Surgeons-categorized Level I hospitals, all other hospitals, and outpatient treatment facilities. Only 22 percent of the malpractice claims were found in Level I facilities, whereas 58 percent were found in other hospitals and 20 percent came from outpatient facilities. Not surprisingly, the indemnity awards were more than two times higher in other hospitals than in Level I hospitals. However, the legal dollars spent in defense per claim were two times higher in Level I than either outpatient hospitals or outpatient treatment facilities, suggesting that Level I malpractice claims are more defensible. We have identified six areas of high potential liability and have made some suggestions for the reduction of risk management in those areas.

Arizona↗

Actinomycosis mimicking pelvic malignancy.

Pelvic actinomyces, usually a complication of an intrauterine device (IUD), is uncommon and may present a diagnostic dilemma because of an atypical clinical presentation. We present a patient with a cervical tumor, extensive parametrial induration with involvement of the posterior bladder wall, and regional lymph nodes which mimicked advanced cervical cancer and presented a significant diagnostic problem.

Actinomycosis↗

Chemotherapy in a pregnant rat model. 1. Mitomycin-C: pregnancy-specific kinetics and placental transfer.

Although cancer complicates pregnancy infrequently, its occurrence jeopardizes maternal and fetal well-being. Treatment with chemotherapeutic agents may adversely affect rapidly dividing fetal tissue, while physiologic changes in pregnancy may alter maternal drug disposition. Previous work on placental transfer and pregnancy-specific kinetics of antineoplastic agents is limited, making the establishment of treatment guidelines for the pregnant cancer patient difficult. Using a pregnant rat model and sensitive HPLC methodology we quantitated the placental transfer and resulting fetal exposure of mitomycin-C (MMC), an alkylating agent. Following maternal dosing, the relative fetal exposure was 6.4%, indicating that MMC does cross the placenta, although to a limited degree. Significant pregnancy-specific alterations in drug disposition, including higher plasma concentrations and decreased clearances in pregnant animals, highlight the need for drug-level monitoring and possible dosage modification when these agents are used in pregnancy.

Amniotic Fluid↗

Chemotherapy in a pregnant rat model. 2.5-fluorouracil: nonlinear kinetics and placental transfer.

As more women postpone childbearing into their later reproductive years (M. A. Adams, G. P. Oakley, and J. S. Marks, J. Amer. Med. Assoc. 247, 493, 1982), the incidence of cancer in pregnancy is likely to increase. Information regarding the placental transfer and pharmacokinetics of antineoplastic agents is limited. The purpose of this study was to determine the kinetics of 5-fluorouracil, a fluorinated pyrimidine with known nonlinear kinetics (J. M. Collins, R. L. Dedrick, F. G. King, et al., Clin. Pharmacol. Ther. 28, 235, 1980) in a pregnant rat model and compare maternal and fetal disposition. A significant amount of 5-fluorouracil crosses the placenta and the relative fetal exposure increases in a dose-dependent fashion. In the pregnant rat model, 5-FU exhibited nonlinear pharmacokinetics as reflected by an increasing half-life, and a greater than proportional increase in the area under the concentration-time curve (AUC) with increasing dose. Fetal saturation of elimination occurred at a lower dose than in the maternal compartment. The significance of these findings to observed embryotoxicity is discussed in a pharmacodynamic model relating the pharmacokinetic behavior of a drug to its embryotoxic effects.

Animals↗

Reliability of frozen section examination in identifying poor prognostic indicators in stage I endometrial adenocarcinoma.

Management of Stage I adenocarcinoma of the uterus includes hysterectomy, bilateral salpingo-oophorectomy, and selective paraaortic and pelvic lymphadenectomy. Postoperative radiation therapy (RT) is selectively employed in patients with histologically defined poor prognostic indicators. We attempted to identify these poor prognostic indicators by frozen section (FS) at primary surgery in 55 patients with Stage I endometrial adenocarcinoma; we found an excellent correlation between the results obtained on gross examination of the uterus with selected FS and the results after extensive sampling and microscopic examination of permanent section (PS). The depth of myometrial invasion was accurately predicted in 96.5%, and histologic grade in 94.5% of these patients. Sixty-six percent of patients with occult invasion of the cervix on PS were identified on FS. Using the above criteria, we identified by FS all patients (15/55) who required adjuvant RT obviating the need for pelvic lymph node dissection. On the basis of our preliminary data, we recommend the use of careful gross examination and selective FS to identify patients requiring selective pelvic and paraaortic lymphadenectomy and adjuvant therapy, thereby eliminating the need for staging lymph node dissection with its associated morbidity and complications.

Adenocarcinoma↗

Vascular access in gynecologic cancer using the Groshong right atrial catheter.

From December 1986 through July 1987, forty-one Groshong catheters were inserted in 38 patients with invasive gynecologic cancer for a cumulative total of 4170 days of patient use. (mean catheter indwelling time: 93 days; range: 3-300 days). A supraclavicular approach was used to cannulate the brachiocephalic vein in 31 patients. In 6 patients, the subclavian vein was cannulated via an infraclavicular approach, while 4 patients had the catheters placed via external jugular venous cutdown. Thirty-seven catheters were inserted at the bedside without fluoroscopy using the Seldinger technique and a peel-away catheter introducer sheath. A chest x-ray was used to confirm the right atrial position of the catheter. Major complications included two pneumothoraces, and three catheter-related cases of sepsis. A unique feature of the Groshong catheter is a pressure-sensitive two-way valve at the intravascular end, minimizing the potential for air embolism and back-bleeding. This eliminates the need for a heparin flush or external clamping, but permits blood sampling. Catheter insertion and maintenance procedures at bedside are simple, time saving, and cost effective. With the increasing use of continuous chemotherapy infusion protocols, use of vesicant drugs, hyperalimentation, and the need for outpatient therapy, we recommend early placement of the Groshong catheter in the oncology patient.

Adolescent↗

Acellular vascular matrix: a natural endothelial cell substrate.

A preliminary assessment was made of the acellular vascular matrix graft as a substrate for endothelial cell seeding, with respect to surface pretreatment (none versus fibronectin and/or serum) and presence of exogenous growth factor. Arteries were harvested from greyhounds and exposed to a sequential detergent extraction process to produce the acellular vascular matrix. Human umbilical vein endothelial cells were grown in tissue culture, harvested in first passage, then seeded at 10(5) cells/cm2 on sections of acellular vascular matrix and on gel-coated polystyrene positive controls. After 18 hour incubation, endothelial cell-seeded acellular matrices were fixed and processed for histologic and planimetric analysis; control wells were fixed and endothelial cells were counted by planimetry. Pretreatment of the acellular vascular matrix was found to have no effect on the percentage of endothelial cell coverage of the matrix. There was significantly better endothelial cell coverage of the acellular matrix than on matched gel-treated polystyrene control wells. Withdrawal of growth factor resulted in a significant reduction in endothelial cell coverage for all acellular vascular matrix groups. Growth factor withdrawal also significantly reduced attachment of endothelial cells on gel-treated polystyrene. Cell surface area was significantly smaller when growth factor was withdrawn from all groups except from the acellular vascular matrix without pretreatment. We conclude that: (1) the acellular vascular matrix is conductive to endothelial cell adherence and spreading even without pretreatment; and (2) sudden withdrawal of exogenous growth factor may impair early coverage of substrates by endothelial cells due to an effect on their adherence or spreading.

Animals↗

Efficacy of prophylactic antibiotics in vascular surgery: an arterial wall microbiologic and pharmacokinetic perspective.

This prospective study examined microbiologic features of arterial tissue and pharmacokinetics and bioactivity of cefamandole and cefazolin in patients undergoing elective primary prosthetic aortoiliofemoral/infrainguinal reconstruction. Double-blind, randomized, perioperative prophylaxis (1 gm intravenously every 6 hours for nine doses) with cefamandole or cefazolin was administered to 47 patients. Specimens of blood serum, subcutaneous fat, thrombus, atheroma, and arterial wall were obtained for culture and minimal inhibitory concentration and drug level analysis by high-pressure liquid chromatography. The serum half-life (hr +/- SEM) was 1.43 +/- 0.36 for cefamandole and 2.22 +/- 0.40 for cefazolin. Over the first 2 hours of surgery and for all time intervals combined, the serum concentration of cefazolin was significantly higher (p less than 0.025) than cefamandole. Irrespective of sampling time, the tissue concentration of cefazolin was significantly greater (p less than 0.005) than cefamandole. Positive arterial tissue cultures were obtained in 12 of 29 patients (41.4%) from 23 of 116 (19.8%) arterial tissue specimens. Coagulase-negative Staphylococcus was the predominant isolate, 64 of 93 (68.8%). Twenty-five of the 51 coagulase-negative staphylocci tested (49%) were slime-producers. During surgery, the arterial tissue concentration of cefamandole fell below the geometric mean minimal inhibitory concentration against all organisms combined, and against S. aureus (with the highest minimal inhibitory concentration of the prevalent isolates), significantly more often than the concentration of cefazolin. The data show that a significant number of primary elective aortoiliofemoral/infrainguinal reconstructions are associated with positive arterial tissue cultures, which represent a potential source of graft infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Arteries↗

Fibrinolytic treatment of residual thrombus after catheter embolectomy for severe lower limb ischemia.

Intraoperative intraarterial fibrinolytic therapy (IIFT) was employed in 28 patients with acute limb ischemia. In 17 patients, significant residual calf thrombus was demonstrated by completion arteriography after standard balloon catheter thromboembolectomy, whereas in 11, pretreatment arteriography was not obtained. With the patient systemically heparinized, a bolus of fibrinolytic agent was instilled into the distal vessels below an inflow occlusion clamp. Among the 17 patients under angiographic control, arteriography was repeated after 30 minutes and a second bolus was injected if significant residual thrombus was still present. Successful lysis was achieved in 88% of these 17 limbs and streptokinase (SK) and urokinase (UK) were equally effective. The dosage of SK varied between 50,000 and 150,000 units (seven patients) and of UK between 35,000 and 150,000 units (21 patients). Serum fibrinogen levels declined significantly after IIFT (t test; p less than 0.05), but the average level remained within the normal range. Major bleeding developed in two patients, both of whom received SK and underwent a concomitant major abdominal vascular procedure, with a severe fall in fibrinogen values to 10 and 17 mg/dl. A minor groin hematoma occurred in one patient treated with UK. There was a significant difference in the incidence of bleeding between SK (2/7) and UK (1/21) (chi 2; p less than 0.05). Compartment syndrome developed in six limbs (21%). Amputation was required in two patients (7%). There was no correlation between prolongation of ischemia time as a result of IIFT and the incidence of compartment syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization↗