Prevalence of bacterial burden on macroscopic contaminants of orthopaedic surgical instruments following sterilization.

BACKGROUND: Macroscopic contamination of orthopaedic instruments with particulates, including cortical bone and polymethyl methacrylate (PMMA) bone cement, that have previously undergone pre-operative sterilization is frequently encountered peri- or intraoperatively, calling into question the sterility of such instruments. AIM: To determine if macroscopic contaminants of orthopaedic surgical instrumentation maintain a bacterial burden following sterile processing, and to determine the most commonly contaminated instruments and the most common contaminants. METHODS: Macroscopic contaminants in orthopaedic instrument trays were collected prospectively at a single tertiary referral centre over a 6-month period from August 2021 to May 2022. When identified, these specimens were swabbed and plated on sheep blood agar. All specimens were incubated at 37 °C for 14 days, and inspected visually for colony formation. When bacterial colony formation was identified, samples were sent for species identification. RESULTS: In total, 33 contaminants were tested, and only one contaminant was found to be growing bacterial colonies (Corynebacterium sp.). The items most commonly found to have macroscopic contamination were surgical trays (N=9) and cannulated drills (N=7). The identifiable contaminants were bone (N=10), PMMA bone cement (N=4) and hair (N=4). Eleven macroscopic contaminants were not identifiable. CONCLUSION: This study found that 97% of macroscopic orthopaedic surgical instrument contaminants that underwent sterile processing did not possess a bacterial burden. Contaminants discovered during a procedure are likely to be sterile, and do not pose a substantially increased risk of infection to a patient.

Early results of infragenicular revascularization based solely on duplex arteriography.

PURPOSE: Recent reports have both advocated and questioned the utility of duplex arteriography (DA) as the sole preoperative imaging modality for planning infragenicular revascularization. This study compares the outcome of patients with critical limb ischemia who underwent infragenicular vein grafts on the basis of DA alone versus conventional preoperative contrast arteriography (CA). METHODS: The study group is composed of 23 consecutive patients who underwent infragenicular vein bypass grafting solely on the basis of preoperative DA from 1998 to 1999. They were compared with 50 consecutive patients who underwent infragenicular vein bypass grafting after CA from 1996 to 1998. Peak systolic velocity and end-diastolic velocity of potential target arteries were recorded during DA studies. In situ saphenous vein grafts were used preferentially, and technical adequacy of all grafts was assessed with completion duplex or arteriography. RESULTS: DA and CA groups were comparable on the basis of age and risk factors. In one limb (4%), the target artery selected by DA was abandoned because of dense calcification. No other revision in target or inflow artery was required on the basis of intraoperative completion studies. At 1 year, primary graft patency (78% vs 70%, P =.72) and limb salvage (70% vs 81%, P =.21) were comparable between the two groups. In the DA group, mean preoperative target artery peak systolic velocity in patent versus failed grafts was 49 +/- 18 cm/s versus 31 +/- 9 cm/s (P =.04), whereas mean end-diastolic velocity was 22 +/- 7 cm/s versus 14 +/- 8 cm/s (P =.08). CONCLUSION: Infragenicular revascularization directed by DA alone provides early graft patency and limb salvage rates comparable to similar procedures that are based on CA. Preoperative DA target artery velocities may predict outcome and improve target selection. These initial results justify further clinical testing of DA as the primary imaging modality for planning infragenicular vein grafts.

Pedal branch artery bypass: a viable limb salvage option.

PURPOSE: We reviewed our experience with pedal branch artery (PBA) bypass to confirm the role of these target arteries for limb salvage and to identify patient and technical factors that may be associated with graft patency and limb salvage. METHODS: In this retrospective study we analyzed 24 vein grafts to PBAs performed from 1988 to 1998 for limb salvage in 23 patients who had no suitable tibial, peroneal, or dorsal pedal target arteries. These PBA grafts were compared with 133 perimalleolar posterior tibial, defined at or below the ankle, or dorsalis pedis bypass grafts performed contemporaneously; the Kaplan-Meier life table was used in the analysis of graft patency and limb salvage. Life table analyses and logistic regression analysis of prognostic patient variables were also performed. RESULTS: The PBA bypass represented 3% of infrainguinal revascularizations for chronic critical limb ischemia at our institution over the study period. Patients who received PBA bypasses were more likely to be male (92% vs. 69%, P =.02) with lower incidences of overt coronary artery disease (33% vs. 50%, P =.12) and stroke (0% vs 15%, P =.04), and a higher incidence of end-stage renal disease (21% vs 8%, P =.06) than those undergoing perimalleolar bypass. Seventeen percent of PBA bypasses were performed with the anterior lateral malleolar artery, a vessel not previously described as a common bypass target. Two-year primary patency and limb salvage for PBA versus perimalleolar bypass was 70% versus 80% (P =.16) and 78% versus 91% (P = .28), respectively. Patency and limb salvage rates were no different in bypasses with above-knee or below-knee inflow arteries. CONCLUSION: An autogenous vein bypass to the PBA, though rarely required, provides acceptable primary patency and limb salvage when compared with perimalleolar tibial artery bypass when no suitable, more proximal target arteries are available. The PBA bypass should be considered before major amputation is undertaken.

A specific inhibitor of apoptosis decreases tissue injury after intestinal ischemia-reperfusion in mice.

PURPOSE: Apoptosis is a stereotypical pathway of cell death that is orchestrated by a family of cysteine endoproteases called caspases. This study examined the effect of apoptosis inhibition with a specific caspase inhibitor on murine intestinal viability after ischemia-reperfusion (IR). METHODS: C57Bl6 X SV129 mice underwent segmental small bowel ischemia by vascular isolation of 10 cm of terminal ileum. In separate experiments, the ischemic time was varied from 30 to 130 minutes with a reperfusion interval of 6 hours. The degree of small bowel injury was quantified from 1 to 5 (increasing severity) by standardized, blinded histologic grading. The degree of apoptosis was assessed with a specific assay (terminal deoxyamcleotydil transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]) and quantified by calculating the apoptotic index (apoptotic cells/10 high-power fields). To evaluate for activation of interleukin-1beta converting enzyme we measured tissue mature interleukin-1beta levels using a specific enzyme-linked immunosorbent assay. To evaluate the effect of apoptosis inhibition on intestinal viability after IR, mice received 3.0 mg of the caspase inhibitor ZVAD (N-benzyloxycarbonyl Val-Ala-Asp-Ome-fluoromethylketone) subcutaneously before and after IR in five divided doses (n = 11), the same dose of ZFA (N-benzyloxycarbonyl Phe-Ala fluoromethylketone), a structurally similar molecule with no anticaspase activity (n = 9), or sham operation (n = 6). RESULTS: A linear relationship existed between ischemic interval and histologic grade (r = 0.69, P <.006). Increasing the ischemic interval from 0 to 50 minutes was associated with a fivefold increase in apoptotic index (P =.05). Ischemic bowel was measured to have an average of 57.3 +/- 7.8 pg/mL whereas normal bowel had an average of 1.8 +/- 0.5 pg/mL of mature interleukin-1beta present. Mice tolerated multiple injections of ZVAD and ZFA without signs of toxicity. Animals treated with ZVAD (apoptosis inhibitor) had little injury after 50 minutes of ischemia and 6 hours of reperfusion (injury grade 1.8) compared with sham controls (injury grade 1.2, P =.7) and had significantly less injury than mice treated with ZFA (placebo) (injury grade 3.0, P <.006). CONCLUSIONS: Increasing ischemic interval in a segmental small bowel murine IR model is associated with increased histologic injury and augmented apoptosis as evidenced by increased TUNEL staining and interleukin-1beta converting enzyme activation. Inhibition of apoptosis with a specific caspase inhibitor significantly diminishes the degree of small bowel injury.

Treatment of life-threatening ventricular arrhythmias with nonguided surgery supported by electrophysiologic testing and drug therapy.

Forty-six patients who had coronary artery disease, left ventricular aneurysm and life-threatening ventricular tachyarrhythmia underwent surgical treatment to eliminate or facilitate control of the arrhythmia. Surgery was performed without the assistance of intraoperative mapping techniques. Forty-three patients underwent preoperative or postoperative electrophysiologic testing, or both, and antiarrhythmic therapy was added, when indicated, postoperatively. The patients had a mean age of 63 years, a mean preoperative left ventricular ejection fraction of 27 +/- 9% and a mean preoperative left ventricular end-diastolic pressure of 23 +/- 9 mm Hg. Twenty-one patients (46%) underwent surgical treatment within 2 months of their last myocardial infarction. The overall operative mortality rate was 6.5% (three patients). Eighteen of the 43 operative survivors were discharged from the hospital on no antiarrhythmic therapy, whereas 25 received additional antiarrhythmic treatment. During a mean follow-up period of 36 months (range 2 to 88), there were 13 deaths; eight patients died suddenly, three died of congestive heart failure, one of myocardial reinfarction and one from a noncardiac cause. The overall cumulative cardiac mortality rate at 1, 2 and 3 years was 16, 22 and 35%, respectively, whereas the sudden cardiac death rate was 5, 12 and 20%, respectively. This experience suggests that high risk patients who undergo nonguided surgery for life-threatening ventricular arrhythmia and left ventricular aneurysm have a relatively low surgical mortality and a better long-term survival than previously reported. However, if utilized, such an approach must be systematically supported by perioperative electrophysiologic testing to determine the need for supplemental antiarrhythmic therapy.

Cardiac operations in patients over 80 years of age.

Twenty-five patients between 80 and 89 years of age underwent a variety of cardiac surgical procedures. Operative mortality was 4%. Perioperative complications were frequent and resulted in an increased hospital stay postoperatively (mean 19.5 days). At a mean follow-up of 29.1 months, 21 patients (84%) are alive, with improvement in functional class from 3.4 to 2.0 (p less than 0.005). Cardiac operations can be performed in patients over 80 years of age with low mortality and significant symptomatic benefit. A high incidence of complications necessitates careful monitoring but should not represent a contraindication to the surgical management of advanced heart disease in this group.

Urgent myocardial revascularization for dissection of the left main coronary artery: a complication of coronary angiography.

Acute subintimal dissection of the left main coronary artery (LMCA) is a rare but devastating complication of selective coronary angiography. The compromise of the coronary blood flow to an extensive area of myocardium becomes clinically evident in most patients shortly after the injury. Three patients who had catheter-induced LMCA dissection were successfully managed with aorta-coronary artery bypass. We recommend that urgent myocardial revascularization using standard techniques should be carried out in all patients following this injury.

Left ventricular function in end-stage renal disease: echocardiographic classification.

We used echocardiography (ECHO) to detect pericardial effusions and assess left ventricular (LV) function in 39 patients with end-stage renal disease (ESRD). Pericardial effusions were present in 24 patients (62%). Thirty-one patients (79%) had concentric hypertrophy and 20 patients (51%) had decreased LV compliance. The majority of patients with concentric hypertrophy and decreased LV compliance had normal LV internal dimensions and contractility. Six patients (15%) had ECHO results compatible with congestive cardiomyopathy. An echocardiographic distinction between congestive heart failure, decreased LV compliance, and salt and water overload in ESRD has allowed an appropriate therapeutic decision as to whether to administer cardiac glycosides or increase ultrafiltration as a treatment for pulmonary congestion. ECHO is a safe, convenient, and noninvasive method of assessing serial LV function, and it can be used to document progressive deterioration of LV function in ESRD.

Symptomatic methemoglobinemia with a commonly used topical anesthetic, cetacaine.

Severe cyanosis resulting from acquired methemoglobinemia after application of a topical anesthetic, Cetacaine spray, occurred in a 37-year-old patient following bronchoscopy for postoperative atelectasis. Response to methylene blue therapy was dramatic and complete. Attention is drawn to a dangerous adverse effect of this commonly used topical anesthetic agent.

Lobar pulmonary hemorrhage. An unusual complication of Swan-Ganz catheterization.

Massive lobar pulmonary hemorrhage related to Swan-Ganz catheterization represents a catastrophic complication that, to our knowledge, has received little attention in the literature. Our experience with two recent cases emphasizes the life-threatening nature of such bleeding as well as the potential for patient salvage after urgent resectional therapy. A spectrum of pulmonary vascular injuries is incurred after the insertion of a balloon-tipped catheter, and there are therapeutic approaches for each. The anticoagulation associated with cardiac surgical procedures prompts us to suggest that the technique of insertion and the use of the Swan-Ganz catheter in these patients be modified to avoid this complication.

Use of saphenous vein to extend and relocate coronary arteries: clinical experience during extensive reconstructive operations of the aortic root.

Eight patients with advanced disease of the aortic root involving the origins of the coronary arteries have been operated on with resection of the entire aortic root including the ostia of the coronary arteries. Reconstruction was performed by insertion of a composite prosthesis; extension and relocation of the proximal portion of the coronary arteries was accomplished with saphenous vein segments. Two patients had infected aortic valve prostheses, three patients had acute aortic dissection and three had annuloaortic ectasia. Seven of eight patients survived the operation, the only operative death occurring in a patient submitted to an operation in a shock state following rupture of the aorta. There was, however, a high incidence of subsequent late deaths resulting from continued infection and from central circulatory failure. An analysis of this series of patients suggests the possibility that a reconstruction that relocates and extends the proximal portion of the coronary circulation may provide a total blood flow that is inadequate or inappropriate, and further suggests that the methods used in the reconstruction of the proximal circulation may be critical to the prevention of myocardial hypoperfusion.

Epicardial pacemaker complicated by cardiac tamponade and constrictive pericarditis.

Following insertion of an epicardial pacemaker, our patient developed cardiac tamponade complicated by subacute constrictive pericarditis. Echocardiographic findings and intracardiac pressures were typical of constrictive pericarditis, which was confirmed at surgery. Although rare, these unusual complications should be considered in patients who develop evidence of reduced cardiac output following either transvenous or epicardial electrode placement.

Posterior pseudoaneurysm of the left ventricle: a prospective echocardiographic diagnosis.

A 69-year-old man had a posterior pseudoaneurysm of the left ventricle shown by echocardiography and cardiac catheterization. The patient had resection of the pseudoaneurysm and did well. The case illustrates the usefulness of echocardiography for detecting and evaluating left ventricular pseudoaneurysm and the effectiveness of surgery for that entity.

Left ventricular aneurysm resection: indications and long-term follow-up.

Forty-four patients had resection of a chronic postinfarction left ventricular aneurysm. Operative indications were heart failure, angina, and ventricular arrhythmias. Twenty-six patients (59%) had coronary grafting in addition to aneurysmectomy. The operative mortality rate was 4.5% (2/44), and late mortality (mean follow-up, 31 months) was 17.9% (7/39). Preoperatively all patients were in New York Heart Association Functional Class III or IV; 91% were Class I or II postoperatively. Coronary bypass grafting did not increase the operative mortality rate, and long-term survival was similar between those receiving coronary grafts and those not receiving grafts. Postoperative ventriculograms were evaluated in 10 patients by means of a system of internal grids. Amount of regional myocardial contraction correlated well with the patient's postoperative functional capacity. It is concluded that ventricular aneurysmectomy in combination with coronary bypass grafting is safe and effective, resulting in marked improvement in the patients' functional capacity and longevity.

Considerations in the management of open-heart surgery in uremic patients.

Life-threatening complications involving the central circulation commonly occur in uremic patients. The growing number of individuals maintained on long-term hemodialysis along with repeated demonstrations of their ability to tolerate major operative procedures are responsible for increasing surgical experience in this group. Despite a high incidence of subacute bacterial endocarditis (SBE) and accelerated coronary atherosclerosis, exposure of such patients to open-heart operations has been limited. Our management of two patients who recently underwent valvular replacement is outlined and a review of the literature revealed that, during the past decade, 20 uremic patients have undergone a variety of cardiac procedures. The catastrophic results of medical therapy in such individuals with SBE are emphasized and early surgical intervention is recommended.