Prevention of vascular graft infection by rifampin bonding to a gelatin-sealed dacron graft

This study examines the efficacy of rifampin bonding to a gelatin-sealed knitted Dacron graft to prevent perioperative bacteremic vascular graft infection. Antibiotic bonding was obtained by soaking grafts for 15 minutes in a 1 mg/ml saline solution of rifampin at 37°C. Nineteen dogs had thoracoabdominal aortic bypass: seven (group I) received a rifampin treated graft; six (group II) received an untreated gelatin-coated graft; and six (group III) received an uncoated Dacron graft. Two days later bacteremic challenge was produced by rapid intravenous injection of 5×10 ⁵ colony forming units of methicillin resistantStaphylococcus aureus.Grafts were harvested five days after this challenge and cut into 10 fragments, each submitted to bacterial counts. Results were expressed as CFU/cm ² of graft material. In group I, no graft was infected, whereas all grafts in groups II and III were infected (p<0.05). Median bacterial counts from the infected fragments (median±SD) were similar in groups II (2.5×10⁵ CFU/cm²) and III (4×10⁴ CFU/cm²). Blood cultures at time of sacrifice were negative in all dogs in group I and positive in five of six dogs in groups II and III. Cultures of liver, spleen, kidney, and lung specimens were always negative in group I and positive in 22 of 24 specimens in group II and 23 of 24 specimens in group III. Soaking a gelatin-sealed Dacron graft in rifampin solution evidently prevents early bacteremic graft infection and secondary foci of infection in this model.Presented at the Annual Meeting of the French Vascular Surgery Society, Nancy, France, May 18–19, 1990.     

Transfemoral intraluminal graft implantation for abdominal aortic aneurysms

This study reports on animal experimentation and initial clinical trials exploring the feasibility of exclusion of an abdominal aortic aneurysm by placement of an intraluminal, stent-anchored, Dacron prosthetic graft using retrograde cannulation of the common femoral artery under local or regional anesthesia. Experiments showed that when a balloon-expandable stent was sutured to the partially overlapping ends of a tubular, knitted Dacron graft, friction seals were created which fixed the ends of the graft to the vessel wall. This excludes the aneurysm from circulation and allows normal flow through the graft lumen. Initial treatment in five patients with serious co-morbidities is described. Each patient had an individually tailored balloon diameter and diameter and length of their Dacron graft. Standard stents were used and the diameter of the stent-graft was determined by sonography, computed tomography, and arteriography. In three of them a cephalic stent was used without a distal stent. In two other patients both ends of the Dacron tubular stent were attached to stents using a one-third stent overlap. In these latter two, once the proximal neck of the aneurysm was reached, the sheath was withdrawn and the cephalic balloon inflated with a saline/contrast solution. The catheter was gently removed caudally towards the arterial entry site in the groin to keep tension on the graft, and the second balloon inflated so as to deploy the second stent. Four of the five patients had heparin reversal at the end of the procedure. We are encouraged by this early experience, but believe that further developments and more clinical trials are needed before this technique becomes widely used.     

Infrainguinal polytetrafluoroethylene grafts: Saved limbs or wasted effort? A report on ten years' experience

Two-hundred and twenty-four infrainguinal polytetrafluoroethylene reconstructions were performed for critical ischemia over a 10 year period: 48 to the above-knee popliteal artery, 113 to the below-knee popliteal artery, and 63 to the tibial vessels. The cumulative patency rates were 84±6% and 63±9% for above-knee popliteal, 53±5% and 35±7% for below-knee popliteal, 45±6% and 30±9% for tibial vessels at one and five years respectively. Limb salvage rates were 81±6% and 73±9% (above-knee popliteal), 69±5% and 57±9% (below-knee popliteal), 64±7% and 32±10% (tibial vessels) at one and five years respectively. Graft occlusion did not result in limb loss in 32 cases. Preoperatively, 54% of the patients had limited mobility while 43% were regarded as severely restricted. At follow-up, 57% of the patients were considered to be independent, 26% had limited mobility, and 17% were still severely restricted. Polytetrafluoroethylene provides good short-term limb salvage and improved mobility in patients with critical ischemia and poor life expectancy. Its use is well worth the effort.     

Late results of small untreated abdominal aortic aneurysms

We report our experience with 73 patients who were initially selected for nonoperative management of an abdominal aortic aneurysm less than 5 cm in diameter. Size of the aneurysm was determined by ultrasound (34); arteriography (16); computerized tomography (17); plain x-ray (4); and magnetic resonance imaging (2). End points of the study were subsequent elective resection, rupture, death from cause other than rupture, or an intact aneurysm followed for a minimum of three years. Overall, 28 (38%) aneurysms were subsequently resected on an elective basis; four (5%) ruptured; 15 (21%) were intact at the time of the patient's death; and 26 (36%) remained intact during follow-up of 3 to 6.5 years. Indications for elective resection were aneurysm enlargement (21); symptoms suggesting impending rupture (3); and improvement in medical condition (4). In the 43 aneurysms initially less than 4 cm diameter, 16 (37%) had elective resection and one (2%) ruptured, and in the 30 that were 4–4.9 cm, 12 (40%) were resected and three (10%) ruptured. The four aneurysms that ruptured had enlarged to greater than 5 cm prior to rupture. We conclude that aneurysms less than 4 cm can be safely followed. Aneurysms 4–4.9 cm should be considered for operation, depending upon the size of the aneurysm, patient's life expectancy, and risk factors for surgery. Any aneurysm that enlarges should be resected, especially if the aneurysm becomes larger than 5 cm in diameter.Presented at the Annual Meeting of the Southern California Vascular Surgical Society, September 21–23, 1990.     

Chylous ascites following abdominal aortic surgery

Three patients, two women, one man (mean age 74 years), who had abdominal aortic aneurysms (2) or aortobifemoral surgery (1), developed chylous ascites postoperatively. They were studied to determine their clinical course and develop a plan for management of this complication. In each patient, the ascites was not manifest until abdominal swelling developed two weeks after operation, and the problem was confirmed by the finding of milky fluid on paracentesis. A low serum albumin (mean 2.6 gm) was also characteristic. The ascites was not altered by parenteral nutrition or reduction of dietary fat and ingestion of medium chain triglycerides. In one patient (man, age 93) the ascites resolved spontaneously two months after abdominal aortic aneurysm surgery. Another (woman, age 70) was cured following operative ligation of a lymphatic fistula identified at operation five weeks after abdominal aortic aneurysm repair. In the third (woman, age 60), the ascites resolved immediately following placement of a peritoneal venous shunt six weeks after an aortobifemoral bypass. Chylous ascites is rare after aortic surgery and manifests itself about two weeks after operation, at times after discharge from hospital. It has an indolent course, but may resolve spontaneously up to two months after operation. Its course appears not to be foreshortened by diet, including omission of fat, but can be successfully treated surgically with a shunt or fistula ligation. If done early a protracted hospital course may be avoided. Presented at the Ninth Annual Meeting of the Southern California Vascular Surgical Society, Newport Beach, California, September 22, 1990.     

Replacement of the abdominal aorta with an aortic homograft in a patient with an aortic dissection

The use of aortic and femoral homografts in early vascular surgery has been abandoned for the more successful and abundant synthetic substitutes. With the recent introduction of cryopreservation, homograft use has again met with improved success. A 40-year-old man who had a DeBakey Type I aortic dissection initially underwent replacement of the aortic root with a pulmonary homograft. Subsequently, in the presence of an intraabdominal infectious process, progressive mesenteric and lower limb ischemia was treated by replacing the abdominal aorta with an aortic homograft. Thirty-six months postoperative the patient has a functioning gastrointestinal tract and no vascular insufficiency of the lower extremities and no evidence of degeneration of the homograft. Further laboratory studies should be undertaken using the newer and improved cyropreserved homograft in the presence of, or potential for, an intraabdominal infectious process. Presented at the 42nd Annual Meeting of the Southwestern Surgical Congress, LaQuinta, California, April 22–25, 1990.     

Concomitant abdominal aortic aneurysm and colorectal cancer: A decision analysis approach to a therapeutic dilemma

The therapeutic approach to a patient with concomitant abdominal aortic aneurysm and colorectal carcinoma is not clear. Decision analysis helps clarify decision options and quantify therapeutic outcomes. Variables used in decision analysis include life expectancy after resection for colorectal cancer and abdominal aortic aneurysm, rupture rate of abdominal aortic aneurysm, complications of colorectal cancer, complications of abdominal aortic aneurysmorrhaphy, and colorectal resection. The results support the concept that the symptomatic lesion should be treated first. When both lesions are asymptomatic and the aneurysm is 4–5 cm in diameter, it should be resected first, if the colorectal cancer has a <5% chance of obstruction or perforation, as is found in noncircumferential lesions. When the aneurysm is >5 cm, it should be resected first if the cancer has a <22% chance of obstructing or perforating, as with circumferential lesions. Simultaneous resection should be considered for patients with aneurysms >5 cm and cancers with a >75–80% chance of obstruction or perforation, provided the dual procedures can be performed with a <10% operative mortality and <50% complication. rate.The views expressed in this article are those of the author and do not reflect the official policy or position of the Department of the Army, Department of Defense, or the United States Government.     

The role of inflammation in nonspecific abdominal aortic aneurysm disease

The predominant pathologic feature of abdominal aortic aneurysm is elastin destruction, and elastin destruction may be mediated by inflammation. In this investigation serial sections of abdominal aortic aneurysm specimens were selectively stained to study the relationship between inflammation and elastin degradation. In addition, soluble aortic extracts were examined for the presence of immunoglobulins. An inflammatory infiltrate was present in 8 of 10 of the abdominal aortic aneurysm specimens examined. The infiltrate was mononuclear, commonly located at the junction of the media and adventitia; it did not codistribute with loss of elastin. The presence of an inflammatory component in abdominal aortic aneurysm was associated with a large amount of immunoglobulin in soluble extracts from aneurysmal tissue compared to atherosclerotic and normal control extracts. This study further characterizes the microscopic pathology of abdominal aortic aneurysm and describes the presence of immunoglobulin in soluble tissue extracts. In addition, the possible role of inflammation in abdominal aortic aneurysm as it relates to protease expression is detailed. Presented in part at the meeting of the New England Vascular Society, September 21–22, 1989, Bretton Woods, New Hampshire.     

Acute pancreatitis following aortic aneurysm repair: Report of three cases

This paper reports three cases of acute pancreatitis that occurred after repair of an abdominal aortic aneurysm. The aneurysms were ruptured in two patients and asymptomatic in one. No patient had biliary disease or history of pancreatitis or alcohol abuse. Two of the patients required operation for drainage and debridement; one died. The etiology and diagnosis are discussed.     

Simultaneous resection of renal carcinoma and abdominal aortic aneurysm

A 62-year-old man with a 6.5 cm abdominal aortic aneurysm and coexistent left renal cell carcinoma was treated by simultaneous radical left nephrectomy and abdominal aortic aneurysm repair. Care was taken to avoid potential infection of the bypass graft by inadvertent contamination with urine. Pathologic examination of the left kidney revealed a renal cell carcinoma, clear cell type, with no evidence of invasion into the renal vein or lymph node metastases. The patient had an uncomplicated recovery and is well and free of disease four years after operation. In cases of equivalently life threatening surgical diseases, simultaneous resection is warranted.     

Inflammatory reactions after vascular prosthesis implantation: A comparison of gelatin-sealed and unsealed dacron prostheses

Despite widespread use of the gelatin-sealed knitted Dacron prosthesis (GDP) in clinical practice owing to its zero porosity, the biological impacts of this graft are still controversial. We conducted a randomized controlled study on 50 patients undergoing abdominal aortic aneurysm repair to evaluate the inflammatory reaction to GDP (n=25) and unsealed knitted Dacron prostheses (UDP, n=25). There were no significant differences in the mean age, size of the aneurysm, operative time, blood loss, or transfusion requirements between the GDP and UDP groups. During the first 7 postoperative days (PODs), slight fever and leukocytosis were noticed in both groups. Significant differences in maximum body temperature, leukocyte count, and plasma C-reactive protein concentration were observed between the GDP and VDP groups on POD 14: 37.2±0.5°C vs 36.9±0.3°C (P=0.019), 8,151±1,788/l vs 6,914±1,501/l (P=0.015), and 32.6±27.5mg/l vs 19.0±15.8mg/l (P=0.048), respectively. By POD 21, however, there were no detectable differences in these variables. Thus, we concluded that GDP caused an inflammatory reaction in the 2nd week after implantation, but ultimately there were no significant differences from UDP by the 3rd week.     

Effect of perigraft seroma fluid on fibroblast proliferation in vitro

Different theories have been postulated in the last 10 years in an attempt to explain the pathogenetic mechanisms involved in perigraft seroma formation. This paper reports our experience with in vitro analysis of the cellular composition and the effect of perigraft seroma fluid on fibroblast proliferative activity. Our results indicate that the cellular component of the fluid was almost exclusively represented by polymor-phonuclear leukocytes. Perigraft seroma fluid was stimulatory on fibroblast growth, while plasma samples from the patient and normal controls were inhibitory. These findings suggest that a perigraft seroma may represent a complex phenomenon which cannot be explained exclusively in terms of fibroblast stimulation or inhibition. This pattern displays a close similarity to experimental observations in the early phases of wound healing. Perigraft seroma formation could be mediated by an intense and persistent chemotactic stimulus on leukocytes, which does not allow normal progression of wound healing through fibroblast growth and collagen deposition.     

Late upper extremity embolic complications of occluded axillofemoral grafts

The use of axillary femoral grafting in the treatment of patients at high risk for aortoiliac reconstruction has become a widely accepted treatment modality. Ischemia and even loss of the donor upper extremity have been reported to occur early after graft occlusion. This report describes three patients who developed emboli to the upper extremity at nine, 15, and 34 months following occlusion of their axillary femoral graft. Based on our experience, we consider an occluded axillofemoral graft a permanent threat to the viability of the donor upper extremity. Anatomic changes suggestive of potential ischemia include: presence of a blind pouch in the graft stump, or Y elongation of the artery with proliferative changes in the intima.     

Thoracic aortic ectasia in a patient with Takayasu's disease

Arterial aneurysm formation occurs in 15 to 20% of patients with Takayasu's disease. The timing of surgical intervention of these aneurysms is controversial. A case of ectasia of the descending thoracic aorta in a patient with Takayasu's disease is presented. The diagnosis and timing of surgical intervention of aneurysms associated with Takayasu's disease are discussed.Presented at the Society for Clinical Vascular Surgery Symposium, April, 1991, Kauai, Hawaii.     

Wound instillation for postoperative pain relief: A comparison between bupivacaine and saline in patients undergoing aortic surgery

In a double blind trial 72 patients having elective aortic surgery were randomized to receive either 40 ml of 0.25% bupivacaine or 40 ml of saline through one or two indwelling wound irrigation catheters every four hours over a total of 48 hours. In transverse incisions the two catheters were randomly placed either subcutaneously or in the rectus sheath; in vertical incisions one catheter was placed subcutaneously. Analgesia was assessed by visual analogue score on Postoperative Days 1 and 2 and the number of doses of intramuscular morphine given during the instillation period. Pulmonary function was monitored by forced expiratory volume and peak flow on Postoperative Days 1 to 5; arterial blood gases were monitored preoperatively and Postoperative Day 2. In all parameters evaluated there was no statistically significant difference between the saline (n=33) or the bupivacaine (n=37) groups. Site of the catheter in the transverse groups made no difference. Comparing vertical (n=21) and transverse (n=49) incisions, the mean visual analogue scores on the first postoperative day were 40 and 29, respectively (p<0.05). Wound instillation with bupivacaine neither improves pulmonary function nor reduces morphine requirements when compared to saline. Transverse incisions may be less painful than vertical ones.     

Intravenous digital subtraction arteriography in the evaluation of vascular grafts

Between 1982 and 1986 intravenous digital subtraction arteriography was used to evaluate vascular grafts in 97 patients (54 males, 43 females). Indications included recurrent symptoms, absent or diminished pulses, a drop in Doppler pressure measurements, and clinical uncertainty with respect to graft patency. Problems identified included graft stenosis, stenosis of the anastomosis or its distal vessels, false aneurysm, arteriovenous fistula and emboli. Forty-eight operations were carried out following intravenous digital subtraction arteriography, and radiographic findings were verified surgically. Twice, intravenous digital subtraction arteriography did not show significant graft findings which were discovered at surgery. Thus intravenous digital subtraction arteriography showed a sensitivity of 95.8% and specificity of 100%. Complications following intravenous digital subtraction arteriography were: two patients developed urticaria, and one superficial thrombophlebitis. There were no cases of pulmonary edema or death. In conclusion intravenous digital subtraction arteriography is very useful in the diagnosis of graft-related problems if done on a selective basis looking at graft and anastomosis site only, intravenous digital subtraction arteriography is done on an outpatient basis, has high sensitivity and specificity, good patient acceptance, is safe, fast and is less expensive than conventional arteriography.     

The management of traumatic aortic tear in the multiply-injured patient

Patients with traumatic aortic tears and severe life-threatening associated injuries require early and expeditious evaluation and treatment in order to improve survival. Diagnostic and treatment priorities, however, are not clearly established in this subset of patients. The purpose of this retrospective analysis was to help identify successful diagnostic and treatment priorities in this group of patients. Between 1979–1989 the medical records of all patients sustaining blunt chest trauma resulting in a traumatic aortic tear were reviewed. There were 11 patients with multiple injuries and this diagnosis was treated at Boston University Medical Center. Five patients had diagnostic peritoneal lavage or an exploratory laparotomy prior to a thoracotomy. Four patients had only a thoracotomy. Two patients in this series had a thoracotomy prior to treatment of suspected intraabdominal injuries. One of these two patients died. Our overall survival rate was 82%. This series suggests that the management sequence in patients with coexistent injuries should include treatment of severe associated injuries prior to treatment of the aortic injury and that initial treatment of traumatic aortic tears is appropriate if there is no evidence of severe life-threatening trauma.     

Acute aortic occlusion secondary to aspergillus endocarditis in an intravenous drug abuser

A 55-year-old black man, an intravenous substance abuser who had an acute arterial embolus to the distal aorta originating from his mitral valve, was noted on pathologic examination of the clot to have aspergillosis emboli. The infective endocarditis also resulted in emboli to the brain with subsequent death.     

A prospective study of a hand-held ultrasound device in abdominal aortic aneurysm evaluation

PURPOSE: Effective treatment of abdominal aortic aneurysm (AAA) requires both early detection and timely repair to reduce aneurysm-related mortality. The purpose of this prospective study was to evaluate the utility of a hand-held ultrasonography (US) device in AAA screening in a Veterans Affairs vascular surgical service. METHODS: During a 16-month period, patients with risk factors for AAA were evaluated in a blinded fashion with a hand-held US device performed by physicians. A conventional abdominal duplex US examination was also performed by a certified vascular ultrasonographer. Results of the hand-held US was compared with the conventional duplex US examination. RESULTS: A total of 104 patients were evaluated (97 men, mean age 67 +/- 6.3 years). The mean times for hand-held and conventional duplex US examinations were 5.3 +/- 3.2 minutes and 3.1 +/- 2.4 minutes (not significant), respectively. Using the conventional duplex US as a reference, the sensitivity and specificity of the hand-held device in detecting a AAA were 93% and 97%, respectively. The positive and negative predictive values of the hand-held device were 89% and 98%, respectively. The likelihood ratios of positive and negative tests of the hand-held US device examination were 82 and 0.14, respectively. The diagnostic accuracy of the hand-held US device as compared with the conventional duplex US was 98%. CONCLUSIONS: A hand-held portable US device is effective and accurate in AAA screening with results comparable to the conventional abdominal duplex examination. Moreover, hand-held portable US for AAA screening can be performed expeditiously during physical examination. It should be used as an extension in routine physical examination in vascular patients.     

Surgical treatment of primary aortoduodenal fistula

Primary aortoduodenal fistula is a rare and potentially fatal condition. Awareness of its existence, precise diagnostic evaluation,and early surgical intervention are essential for the survival of the patient. Although early experience indicated that interruption of the fistula, repair of the enteric defect, oversewing of the aorta and extraanatomic bypass was the procedure of choice, in situ aortic replacement with a prosthetic graft seems to be a viable option. This article includes a case report of a primary aortoduodenal fistula and review of the literature.