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Biomedical subjects

P D Fry

Publications and source records attributed to P D Fry.

At least 37 records · Page 2Linked to original sources
PubMed1987

Predicting failure in polytetrafluoroethylene vascular access grafts for hemodialysis: a pilot study.

In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk.

Blood Vessel Prosthesis↗
PubMed1982

Revascularization of the leg using polytetrafluoroethylene: cumulative patency in patients with claudication and limb salvage.

Of 196 polytetrafluoroethylene bypass grafts in the leg, 113 were placed in the femoropopliteal and 83 in the femorotibial or femoroperoneal position. Claudication was the indication for 31 percent of the grafts, and 67 percent were done for limb salvage. Cumulative patency rates calculated by the life-table method for the femoropopliteal grafts were 66 percent at 1 year, 53 percent at 2 years, and 49 percent at 3 years. Corresponding patency rates for the femorotibial or peroneal grafts were 48, 44, and 36 percent, respectively. An analysis of factors influencing graft patency indicated that the best results were obtained with femoropopliteal grafts done for claudication in the presence of good distal runoff and grafts placed in limbs without previously failed grafts. Graft occlusion was most likely in distal bypasses for limb salvage and limbs with previously failed grafts. It is concluded that alternatives to PTFE bypass should be considered in those patients at greatest risk for graft occlusion. In patients who lack a satisfactory saphenous vein but who must have a bypass graft, polytetrafluoroethylene is an acceptable arterial substitute; however, thrombectomy or revision will be required to maintain patency in a high proportion of cases.

Actuarial Analysis↗
PubMed1982

Polytetrafluoroethylene and bovine grafts for vascular access in patients on long-term hemodialysis.

A 4-year retrospective chart review of patients whose vascular access for hemodialysis was via a polytetrafluorethylene (PTFE) or a bovine graft revealed that cumulative patency differed little between the two groups. The average graft life was 27 months. Those with vascular access through the forearm, particularly with a loop type of graft, fared the best. Recurrent thrombosis was a serious problem. For this the authors recommend elective graft replacement followed by a "rest period" of 2 to 3 weeks. Failing grafts should be repaired as directed by fistulographic findings. Polytetrafluoroethylene seems to be safer, if not more reliable, than the bovine graft. Rupture and life-threatening hemorrhage did not occur with PtFE.

Animals↗
PubMed1980

Aortoenteric fistulas: a preventable problem?

The results of management in 22 patients with secondary aortoenteric fistula are reviewed to determine whether this condition can be prevented. In 14 patients who had resection of an aneurysm, the fistula developed in spite of adequate coverage of the synthetic graft. Most fistulas occurred at sites of anastomosis (81%). Half the patients presented with sudden massive gastrointestinal hemorrhage; however, in 40% hemorrhage had occurred up to 18 months before admission. Endoscopy is the most useful diagnostic modality, but the condition must first be suspected. The most successful definitive management of this problem was removal of the graft and revasoularization of the lower limbs by insertion of an extra-anatomic bypass graft. The overall mortality in the series was 60% and the operative mortality 47%. The preventive aspects of this complication and technical details of the aortic and duodenal closure are discussed. The authors believe that this serious complication of aortic bypass grafting may be prevented by ensuring that the suture line is adequately separated from the small bowel and duodenum.

Aorta↗
PubMed1979

Polytetrafluoroethylene grafts for vascular access for hyperalimentation.

A polytetrafluoroethylene (PTFE) graft from the brachial artery to the axillary vein may provide a safe and trouble-free means of vascular access in selected patients requiring long-term intravenous feeding in the hospital setting. This route for the administration of solutions supplying total parenteral nutrition (TPN) should be considered in persons whose requirement for parenteral feeding is likely to extend over many months and in whom there are other sources of bacteremia which can imitate or be confused with infection of a conventional central venous feeding line. In a 52-year-old man an 8-mm PTFE graft was anastomosed end-to-side to the brachial artery and the axillary vein and brought through a subcutaneous tunnel on the medial aspect of the upper arm. Access to it was obtained by intermittent puncture with a no. 21 butterfly needle. Hyperosmolar TPN solutions flowed easily by gravity drip into the shunt. The graft seemed resistant to infection. This form of vascular access appears to exclude parenteral feeding lines, solutions and catheters as sources of sepsis.

Arteriovenous Shunt, Surgical↗
PubMed1979

Current status of the peritoneovenous shunt for the management of intractable ascites.

Renewed interest in the management of intractable ascites has led to the use of a peritoneovenous shunt for its control. Analysis of Canadian experience with this technique in the last 2 years has demonstrated that there are problems associated with it that have not been reported in the surgical literature. A group of 60 patients who underwent peritoneovenous shunting at several Canadian centres was analysed. The operative mortality was 20% but was related to the underlying disease rather than to the operative procedure. Although the initial response to shunting was excellent in 53%, long-term patency (more than 3 months) was achieved in only 43%, but the procedure greatly improved the quality of life in those patients. The indications for shunting, the complications, results and cumulative patency rates are discussed.

Adult↗
PubMed1978

Initial experience with the polytetrafluoroethylene graft for limb salvage. A report on twenty patients.

The early results of the bypass procedures for limb salvage using the new polytetrafluoroethylene (PTFE) graft are analyzed. Of twenty patients presenting with either severe rest pain or gangrene, patency has been maintained in fourteen for a mean period of thirteen months to date. Particularly satisfying results have been achieved when bypassing into single dominant arteries below the knee where limb salvage and graft patency was obtained in all cases.

Aged↗
PubMed1976

Current surgical approach to toxic megacolon.

Presented evidence illustrates that proctocolectomy performed as an emergency procedure is frequently less than adequate in salvaging patients with toxic megacolon, and a current mortality of 27 per cent is recorded. The mortality and morbidity of this disease are directly related to the delay in recognition and treatment of this complication and to iatrogenic perforation of the colon during colectomy, which results in fecal peritonitis. This is particularly evident when definitive operation is postponed for more than five days after the initial diagnosis of toxic megacolon. The rationale of current adherence to proctocolectomy for this complication is questioned, and a plea is made for the recognition of the life-saving potential for ileostomy-colostomy for selected patients and also for closer and earlier collaboration between surgeon and internist during the management of these patients.

Adult↗
PubMed1975

Ruptured abdominal aortic aneurysm.

A total of 131 surgically treated ruptured abdominal aortic aneurysms have been reviewed. Factors affecting morbidity and mortality rates have been analyzed. In our experience very little improvement has occurred in the last 10 years and the question is raised whether a plateau has been reached in the management of this catastrophic disease. Patient selection is not considered to be the key to better results, since some operated patients inevitably die. Improved technique with better, more rapid control of blood loss, especially from venous tears, will continue to yield better results. Eighty-six nonoperative cases have been studied. Diagnostic accuracy is lower than it should be, often leading to delayed surgery or death.

Age Factors↗