Pulse contour cardiac output in surgical intensive care unit patients.

STUDY OBJECTIVE: To evaluate the ability of arterial waveform contour analysis to measure cardiac output (CO) continuously in postoperative critically ill patients. DESIGN: Thermodilution CO (TDCO) measurements were compared with simultaneous pulse contour CO (PCCO) measurements. SETTING: University hospital surgical intensive care unit. PATIENTS: 29 critically ill surgical patients with indwelling systemic arterial and pulmonary artery catheters. MEASUREMENTS AND MAIN RESULTS: TDCO measurements were compared with PCCO at 1- to 2-hour intervals. Mean TDCO was 5.75 +/- 1.79 L/min, and mean PCCO was 5.76 +/- 1.83 L/min. Analysis of the difference between TDCO and PCCO showed a bias of 0.01 +/- 0.5 L/min. Comparison of the difference between pairs of sequential TDCO measurements and the initial TDCO and subsequent PCCO measurements resulted in a correlation coefficient of 0.64. CONCLUSIONS: The PCCO method appears to be able to estimate changes in CO under the conditions tested, in which PCCO was recalibrated after each TDCO measurement. However, limitations of this method in the immediate postoperative period following aortic aneurysm surgery were identified.

Safety of vein bypass grafting to the dorsal pedal artery in diabetic patients with foot infections.

The results of 56 vein bypasses to the dorsal pedal artery performed in 53 diabetic patients who were admitted with ischemic foot lesions complicated by infection were reviewed. All patients had one or more of the following: infected ulcers (73%), cellulitis (45%), osteomyelitis (29%), gangrene (20%), or abscess (2%). Organisms were cultured from 84% of patients (average 2.6, range 1 to 9 organisms per infection). Elevated temperature (greater than 37.7 degrees C) or leukocytosis (greater than 9.0 x 10(3)/ml) were seen in 13% and 50% of patients, respectively. All patients were treated with broad-spectrum antibiotics, local debridement, wound care, and bed rest. Operative debridement or open partial forefoot amputation were required to control sepsis in 11 patients (20%). Treatment of infection delayed revascularization by an average of 10.7 days. All patients underwent autogenous vein bypasses to the dorsal pedal artery. Two grafts failed within 30 days (3.6%), and one patient died (1.8%). Wound infections developed in seven patients (12.5). One wound infection resulted in graft disruption and patient death at 2 months. Average length of stay of the initial hospitalization was 29.8 days. Fifty-two patients were discharged with patent grafts and salvaged limbs; however, 31 subsequent foot procedures and 35 rehospitalizations were required to ultimately achieve foot healing. Actuarial graft patency and limb salvage were 92% and 98%, respectively at 36 months. Pedal bypass to the ischemic infected foot is efficacious and safe as long as infection is adequately controlled first. The complexity of these situations often requires multiple surgical procedures and extensive wound care, resulting in prolonged or multiple hospitalizations.

Application of the quinolone antibiotic ciprofloxacin to Dacron utilizing textile dyeing technology.

Prosthetic arterial graft infection continues to be a significant and often devastating complication of vascular surgery. The organisms Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) are the primary pathogens causing acute and late graft infections, respectively. The objective of this study was to develop an infection-resistant prosthetic arterial graft by applying the bacteriocidal quinolone antibiotic ciprofloxacin to polyethylene terepthalate (Dacron) via thermofixation (pad/heat), a new application method founded on established textile procedures. We hypothesize that the limited fibrophilic characteristics of ciprofloxacin will permit binding to Dacron and at the same time allow persistent controlled release over an extended period of time. Using pad/heat technology, 33 micrograms (+/- 2.97 micrograms, n = 12) of ciprofloxacin was successfully bound to a 1-cm2 piece of woven Dacron. A full complement of microbiologic assays demonstrated superior, sustained antistaphylococcal activity of the pad/heat Dacron when compared to Dacron dipped into an equivalent concentration of ciprofloxacin. The sustained antimicrobial efficacy of ciprofloxacin pad/heat-treated Dacron opens new avenues in the development of infection-resistant biomaterials based on an understanding of textile chemistry.

Peripheral vascular bypass in juvenile-onset diabetes mellitus: are aggressive revascularization attempts justified?

This study was performed to evaluate the results of peripheral vascular reconstruction for arterial occlusive disease in patients with juvenile-onset diabetes mellitus. The results of 67 bypass procedures performed on 60 patients with juvenile-onset diabetes mellitus between Jan. 1, 1984 and Dec. 31, 1989, were reviewed. These patients had a mean age of 44.4 years (range, 29 to 59 years), with an average age of onset of diabetes mellitus of 9.8 years (range, 1 to 19 years). These procedures comprised 5.5% (67 to 1214) of the bypasses performed on diabetic patients during the same time period at a single institution. Fifty-four of 67 (91%) procedures were performed for limb salvage. Fifty-four (81%) procedures were primary infrainguinal bypasses with saphenous vein (femoropopliteal 19, femorodistal or popliteal-distal 35). Six procedures (9%) were revision procedures, four (6%) were in-flow procedures, and three (4%) were infrainguinal procedures with polytetrafluoroethylene. Thirty-day morbidity and mortality rates were 31% and 0%, respectively. Actuarial patency and limb salvage rates of the primary vein graft group were 66.0% (+/- 10.7) and 83.4% (+/- 8.0%), respectively, at 24 months. Cumulative survival of the entire group at 2 years was 84.1%. Although follow-up in this study is relatively short (24 months), the results suggest that the outcome of vascular reconstruction in patients with juvenile-onset diabetes mellitus is acceptable when compared with procedures performed in adult-onset diabetic and nondiabetic populations. The presence of juvenile-onset diabetes mellitus should not diminish the vascular surgeon's expectations of a successful outcome when considering lower extremity revascularization in these patients.

Safety of saline irrigation for angioscopy: results of a prospective randomized trial.

This study evaluates the hemodynamic effects and safety of saline irrigation necessary to obtain high-quality completion angioscopic studies, as compared with standard completion arteriography during infrainguinal bypass grafting. One-hundred ten patients undergoing primary infrainguinal bypass grafting, were prospectively randomized to either arteriography (N = 50) or angioscopy (N = 60) for a completion study to monitor the bypass procedure. All patients were hemodynamically monitored with pulmonary artery catheters and arterial lines. The arteriography group received an average of 27 ml (range 8-60 ml) of contrast per completion study, with a total administered intraoperative fluid volume of 2095 ml (range 650-4000 ml). The angioscopy group received an average bolus of 321 ml (range 90-650 ml) of irrigation fluid per completion angioscopy study, with a total administered intraoperative fluid volume of 2140 ml (range 850-5000 ml). Transient increases in pulmonary artery systolic and diastolic pressures and central venous pressures were measured during angioscopy. Although these changes reached statistical significance, the changes were of minimal clinical relevance, 1.9 (= 4.5), 1.6 (= 3.0) and 1.4 (= 2.3) mmHg respectively, and returned to baseline levels within 30 minutes. Intraoperative intervention with vasodilators and diuretics, the perioperative cardiac morbidity, and less than 30 day mortality, was not different between the two groups. Pressures generated within 24 bypass grafts were within physiologic arterial range for most of the study. With careful angioscopic technique applied and high quality care extended to the patient, irrigation with saline solution is simple, effective and safe.

Role of angioscopy in reoperation for the failing or failed infrainguinal vein bypass graft.

The purpose of this retrospective study is to review our ongoing experience with the use of angioscopy during reoperation for failed or failing infrainguinal vein bypass grafts and define the role of angioscopy in the management of this clinically demanding patient group. All hospital records, arteriograms, and intraoperative angioscopic video recordings of 79 consecutive failed or failing grafts (76 patients) examined with angioscopy during reoperation between 1987 and 1993 were reviewed. Clinical and intraoperative data, comparison of the preoperative arteriogram and intraoperative angioscopic findings, and surgical decisions or interventions resulting from the additional angioscopic findings were collated and analyzed according to a predetermined protocol. Sixty-six additional angioscopic findings were noted during the 79 reoperations and resulted in 61 additional interventions and surgical decisions with salvage of all or part of the graft in 90.9% in the early (< 30 day) failed (group 1), 84.6% in the late (> 30 day) failed (group 2), and 90.3% in the late (> 30 day) failing grafts (group 3). The amount of residual thrombus within the graft, as assessed by angioscopy after all interventions, was the critical determinant for overall early graft patency (p < 0.001) and long-term patency for all the subgroups after reoperation (group 1, p < 0.001; group 2, p = 0.0016; and group 3, p = 0.0194). Intraoperative angioscopy has an important role in these challenging procedures. It provides additional and useful information that not only influences the conduct and extent of the reoperative surgery but may provide insights into the pathogenesis of graft failure.

Comparison of angioscopy and angiography for monitoring infrainguinal bypass vein grafts: results of a prospective randomized trial.

PURPOSE: This study was designed to determine whether, in primary infrainguinal bypass grafts in which only saphenous vein is used as the graft conduit, routine monitoring with intraoperative angioscopy can improve early graft patency as compared with standard monitoring with intraoperative completion angiography; and to delineate the advantages and disadvantages of these two modalities and their respective roles for the routine monitoring of the infrainguinal bypass graft. METHODS: A total of 293 patients undergoing primary saphenous vein infrainguinal bypass grafting were prospectively randomized and monitored with either completion angioscopy or completion angiography. Clinical parameters, indications for operation, graft anatomy, and configuration were evenly matched in both groups. Forty-three bypasses were excluded from the study after randomization, including 12 veins randomized to angiogram, deemed inferior, and prepared with angioscopy. RESULTS: In the 250 bypass grafts (angioscopy 128, angiography 122) there were 39 interventions (conduit, 29; anastomosis, 8; distal artery, 2), 32 with angioscopy and 7 with angiography (p < 0.0001). Twelve (4.8%) of the 250 grafts failed in less than 30 days, four (3.1%) of 128 in the angioscopy group and eight (6.6%) of 122 in the angiography group (p = 0.11 by one-sided hypothesis test). CONCLUSION: Although no statistical improvement in the proportions of failures in primary saphenous vein bypass grafts routinely monitored with completion angioscopy rather than the standard completion angiogram was demonstrated, the study delineates a trend that favors completion angioscopy for routine vein graft monitoring and demonstrates the advantages of angioscopy in preparing the optimal vein conduit.

Angioscopically directed interventions improve arm vein bypass grafts.

PURPOSE: Our purpose was to determine the incidence and segmental distribution of intraluminal disease in the arm veins of patients in whom saphenous vein was unavailable or inadequate for bypass, determine whether angioscopic evaluation and directed interventions can upgrade the quality of arm vein conduit and improve early graft patency, and describe the angioscopic technique of in situ retrograde arm vein inspection. METHODS: Retrospective review of 109 infrainguinal arm vein bypass grafts in 104 patients performed with intraoperative angioscopic vein preparation and monitoring between August 1989 and March 1992 was undertaken. Four additional arm veins harvested were discarded because of diffuse disease. RESULTS: Intraluminal disease was noted in 71 (62.8%) of 113 arm veins, "webs" in 61 (54%), vein sclerosis in 25 (22.1%), localized stenosis in 11 (9.7%), and thrombus in 7 (6.2%). Intraluminal disease was most common in the cephalic (forearm 49.2%; arm 35.1%) and median cubital (33.3%) veins and least common in the basilic vein (11.7%). Eighty-three angioscopically directed interventions in 68 of 71 abnormal arm veins resulted in upgraded vein conduit quality in 47 (66.1%) of 71. Primary patency (< 30 days) was 99 (90.8%) of the 109 grafts, 85 (95.5%) of 89 grafts with normal or upgraded quality conduits, and 14 (70%) of 20 inferior-quality grafts (p = 0.0024). These differences persisted through 1 year by life-table analysis, (p < 0.001). CONCLUSIONS: Not only is the routine use of the angioscope in arm vein bypass grafting a sensitive technique to detect the intraluminal diseases so prevalent in arm veins but it can also direct endoluminal and surgical interventions that upgrade the quality of the vein conduit and improve early graft patency.