Endovascular repair of a ruptured giant popliteal artery aneurysm.

An 88-year-old woman with hypertension, chronic vein insufficiency, and repeated cellulites in the right lower extremity was admitted to our hospital with a new episode of right leg inflammation and edema associated with fever and leukocytosis. Due to unilateral enlargement of the leg and D-simer levels of 1000 microg/mL, a concomitant deep venous thrombosis was suspected and ultrasonography was performed. Color duplex-scanning found normal flow in the right deep leg veins but revealed an 11-cm-diameter popliteal artery aneurysm. A computed tomography scan confirmed the diagnosis and revealed a large perianeurysmal hematoma, and angiography provided evidence of perianeurysmal bleeding. The patient was unfit for open surgery, so an endovascular approach under local anesthesia was elected. The aneurysm was successfully excluded with an endograft, and 15 months after surgery, the patient is alive and had an uneventful postoperative course.

Surgical treatment of arterial ischemia associated with the use of the angioseal vascular closure device.

BACKGROUND: Despite the theoretical effectiveness of the Angio-Seal closure device to control bleeding after arterial puncture it can increase the risk of ischemia. OBJECTIVES: To describe arterial lesions caused by the device, surgical techniques needed to repair those lesions and surgical outcome in patients who underwent surgery for arterial ischemia after heart catheterization. PATIENTS AND METHODS: Seven patients underwent surgery over a period of 12 months at our institution. Five patients underwent emergency surgery and two a delayed procedure. The cause of ischemia was dissection of an atheroma plaque at the puncture site in four cases, dissection of the superficial femoral artery in one case, thrombosis of the common femoral artery in one case, and plication of the posterior arterial wall in one case. Arterial repair in these patients required the insertion of a vascular graft in three cases, endarterectomy plus angioplasty in two cases, endarterectomy plus graft interposition plus thrombectomy of the superficial femoral artery in one case and endarterectomy plus femoropopliteal bypass in one case. RESULTS: Treatment was successful in all patients. Mean follow up was 7.6 months (range 5-11 months). During the study period one patient died due to cardiopathy. No patients had to be re-operated and no limb losses were recorded. All the patients were asymptomatic from a vascular point of view with normal active lives for their age. CONCLUSIONS: Surgical repair is effective, although, generally, it is not restricted to a simple thrombectomy, requiring the use of different arterial repair techniques.

Evaluation of the Duke criteria in 93 episodes of prosthetic valve endocarditis: could sensitivity be improved?

BACKGROUND: Since publication of the Duke criteria for diagnosing endocarditis, several articles have confirmed their sensitivity when native and prosthetic valves are considered together. OBJECTIVES: To compare the differences between the older von Reyn criteria and the Duke criteria in prosthetic valve endocarditis only, and to determine if the latter's sensitivity could be improved by adding 2 minor criteria: new-onset heart failure and presence of conduction disturbances. METHODS: We retrospectively evaluated 93 episodes of prosthetic valve endocarditis from January 1986 to January 1998 in a teaching hospital, and then analyzed the 76 surgically confirmed episodes to compare the differences between the von Reyn and Duke diagnostic criteria. RESULTS: The von Reyn criteria rejected the diagnosis in 16 of the confirmed episodes, compared with 1 diagnosis missed by the Duke criteria and 1 missed using our suggested modifications. Definite diagnosis (Duke) was established in 60 episodes, compared with a diagnosis of probable (von Reyn) in 36 episodes (P<.001). Our modifications improved the sensitivity of the Duke criteria, diagnosing 70 episodes as definite (P = .02). CONCLUSIONS: As was the case with native valve endocarditis, the Duke criteria proved to be more sensitive than the von Reyn criteria in prosthetic valve endocarditis. The addition of 2 minor criteria (new-onset heart failure and presence of conduction disturbances) could improve the diagnostic sensitivity of the Duke criteria.

Nosocomial infections in patients having cardiovascular operations: a multivariate analysis of risk factors.

A total of 970 adult patients undergoing cardiovascular operations during a 1-year period were eligible for a case-control study on the risk factors for nosocomial infection. Cases were defined as patients in whom a postoperative infection developed. Every case was paired with one uninfected subject. Nosocomial infection occurred in 89 (9.2%) patients. A total of 120 episodes of infection were diagnosed (1.3 episodes per patient). The infection ratio was 12.4%. Surgical site infection was the most common (5.6%), followed by pneumonia (3.2%), urinary tract infection requiring the use of intravenous antibiotics (1.8%), deep surgical site (0.9%), and bacteremia (0.7%). Advanced age, urgent intervention, duration of surgical procedure, blood transfusion, and use of invasive procedures (urinary catheter, chest tubes, nasogastric tube passage) were significantly associated with infection in the bivariate analysis. Nosocomial infection resulted in a significant increase in the length of hospital stay. Cases showed an almost fivefold greater risk of death than controls (odds ratio, 4.73; 95% confidence interval, 1.11 to 6.83; p = 0.009). Age older than 65 years, female sex, and mode of surgical intervention were selected in the multivariate analysis for patients undergoing cardiac operations, whereas general anesthesia or assisted ventilation, central venous catheter, and blood transfusion were the variables selected for patients undergoing operation for vascular disorders. In summary, the recognition of risk factors for postoperative infection in patients undergoing cardiovascular surgical procedures may contribute to improve their prognosis and to more organized surveillance and control activities in the hospital environment.

Partial replacement of mitral valve by homograft. An experimental study.

Satisfactory long-term clinical results with heart valves have renewed the interest in the use of mitral homografts, despite the technical difficulties with their surgical implantation. This report describes the behavior and viability of the partial mitral homograft in the ortotopic position in a chronic sheep model (n = 25). The 20 surviving animals were studied hemodynamically and were anesthetized and electively put to death 3, 6, 9, and 12 months after the operation. All specimens had a normal mitral valve without signs of infection or thrombosis. Light, scanning, and transmission electron microscopy showed the presence of viable endothelial cells from the recipient covering the graft, signs of reendothelialization, and organized dense collagen tissue. The structural integrity was more evident in the fresh mitral homografts. This method may provide consider improvement in the viability of the mitral homograft, and it could be a valid alternative for repair of mitral valve localized pathology.

Repair of nonsevere rheumatic aortic valve disease during other valvular procedures: is it safe?

OBJECTIVE: To investigate the long-term performance of aortic valve repair, we analyzed the results obtained in a 22-year period in patients who underwent repair of nonsevere rheumatic aortic valve disease during other valvular procedures. METHODS: Fifty-three patients (mean 40 +/- 11.6 years of age) with predominant rheumatic mitral valve disease had concomitant aortic valve disease in association with serious tricuspid valve disease in 25 of them. Preoperatively, aortic valve disease was considered moderate in 47.2% of the patients and mild in 52.8%. All patients underwent reparative techniques of the aortic valve (free edge unrolling, 44; subcommissural annuloplasty, 40; commissurotomy, 36) at the time of mitral or mitrotricuspid valve surgery. The completeness of follow-up during the closing interval was 100%, with a mean follow-up of 18.8 years (range 8 to 22.5 years). RESULTS: Hospital mortality rate was 7.5%. Of 49 surviving patients, 26 (53.1%) died during late follow-up. The actuarial survival curve including hospital mortality was 35.4% +/- 8.7% at 22 years. For patients who underwent mitral and aortic valve surgery, the actuarial survival curve at 22 years was 32.3% +/- 13%, whereas for patients who had a triple-valve operation the survival was 37.0% +/- 10.1% (p = 0.07). Twenty-five patients underwent an aortic prosthetic valve replacement. Actuarial free from aortic structural deterioration and valve-related complications at 22 years was 25.3% +/- 9.3% and 12.7% +/- 4.8%, respectively. CONCLUSIONS: Long-term functional results of reparative procedures of nonsevere aortic valve disease in patients with predominant rheumatic mitral valve disease have been inadequate at 22 years of follow-up. According to these data, conservative operations for rheumatic aortic valve disease do not seem appropriate.

Repair of chordae tendineae for rheumatic mitral valve disease. A twenty-year experience.

Sixty-two patients with rheumatic mitral valve disease (mean age 42.2 +/- 10.2 years) underwent repair of chordae tendineae between June 1974 and May 1994. Chordal shortening was done in 38 patients, fenestration in 17, resection of secondary chordae in 3, replacement in 2, and transposition in 2. In 41 patients, mitral commissurotomy was also done. Ring annuloplasty was done in all patients. The mean follow-up was 10.2 years (range 2 months to 20 years). The completeness of follow-up during the closing interval (January to July 1994) was 100%. Hospital mortality occurred in four patients (6.5%) and nine patients died during the late follow-up. The actuarial survival curve at 20 years was 65.8% +/- 10%. Six patients with mitral valve dysfunction (restenosis 4, insufficiency 2) and one with aortic valve dysfunction (structural deterioration of bioprosthesis) underwent reoperation. The actuarial curve of freedom from reoperation at 20 years for mitral valve dysfunction was 73.1% +/- 10.5%. In the 49 surviving patients, a Doppler echographic study during the closing interval showed a mean mitral valve area of 1.9 +/- 0.3 cm2. In the 43 patients with a repaired native valve, absent or trivial mitral regurgitation was documented in 35 and mild or moderate regurgitation in 8. In conclusion, repair of chordae tendineae in rheumatic mitral valve disease when feasible is a stable and safe procedure with a low prevalence of reoperation. However, the type of reconstructive operation and experience of the surgical team are major considerations in successful repair of the mitral valve.

Valve-related complications with the Hancock I porcine bioprosthesis. A twelve- to fourteen-year follow-up study.

Valve-related morbidity and mortality after heart valve replacement with the Hancock I porcine bioprosthesis has been retrospectively analyzed. From June 1974 through December 1976, 253 Hancock I bioprostheses (150 mitral and 103 aortic) were inserted in 220 selected patients who survived the operation and had follow-up until June 1989 (mean follow-up 13.5 years, with an accumulative follow-up of 2956.4 patient-years). One hundred seventeen patients had mitral valve replacement, 70 had aortic valve replacement, and 33 had combined mitral and aortic valve replacement. There were 27 thromboembolic events. The probability of being free from thromboembolism at 14 years was 81.0% +/- 7.4% for the mitral valve replacement group, 85.4% +/- 6.7% for the aortic group, and 67.1% +/- 18.4% for the mitral-aortic group. Fifteen episodes of prosthetic valve endocarditis occurred. There were 10 instances of nonstructural dysfunction (paravalvular leaks) in seven mitral valves (4.6%) and in three aortic valves (2.9%). One hundred twenty-two bioprostheses in 106 patients resulted in structural deterioration. The probability of freedom from structural deterioration at 14 years was 37.2% +/- 3.9% for the mitral group, 43.9% +/- 7.1% for the aortic group, and 30.1% +/- 8.9% for the mitral-aortic group. The logistic regression analysis between age at the time of operation and bioprosthetic life (structural deterioration-free period) demonstrates a linear regression curve (r = 0.53). There were 56 late deaths (27 patients died at reoperation). The actuarial survival rate (including hospital mortality) at 14 years was 57.2% +/- 5.4% for the entire series, with no statistically significant difference between groups. The probability of remaining free from valve-related morbidity and mortality at 14 years was 16.7% +/- 4.8% for the mitral group, 20.8% +/- 6.2% for the aortic group, and 14.0% +/- 7.0% for the mitral-aortic group. The long-term results of this series show that the clinical performance of the Hancock I porcine valve appears satisfactory during the first 6 years. The behavior of this bioprosthesis at 14 years' follow-up changes drastically, because only a minor group of patients is free from valve-related complications, justifying the restriction of its use for selected patients.

Early structural deterioration with the mitroflow pericardial xenograft in the mitral position.

Early structural deterioration with the mitral Mitroflow pericardial valve requiring reoperation occurred in 6 patients. Clinical diagnosis of prosthetic failure was made 5 to 58 months after valve implantation (mean, 38 months). Re-replacement was carried out 22 to 80 months (mean, 55 months) after the initial operation. Mode of failures were cuspal tear without calcification in three valves and massive calcifications in the remaining bioprostheses. High incidence of early structural deterioration of the Mitroflow pericardial valve makes this new prosthesis an unsatisfactory alternative as a substitute in the mitral position.

Behavior of mitral allografts in the tricuspid position in the growing sheep model.

BACKGROUND: On the basis of a previous experience in a chronic sheep model in which partial mitral allografts remained viable and properly functioning 12 months after operation, we assessed the results obtained by replacing the tricuspid valve with fresh antibiotic-preserved mitral allografts. METHODS: Twenty 3-month-old sheep with a mean weight of 23.7 +/- 2.3 kg underwent cardiopulmonary bypass and had a fresh antibiotic-preserved mitral allograft implanted in the tricuspid position with the heart beating under normothermic conditions. The tricuspid valve apparatus was not excised. After a mean follow-up of 13.2 months, the allograft was evaluated by gross inspection and light and electron microscopy. RESULTS: Nine sheep died of technical causes within the first week after operation and 2 at 4 and 6 months of infective endocarditis of the allograft. The hemodynamic study before heart explantation revealed residual tricuspid incompetence in 3 of the 9 survivors. Macroscopic examination showed flexible valves with no signs of structural deterioration, calcification, or thrombosis. Under light and scanning electron microscopic examination, allografts were almost completely denuded of endothelial cells and showed loosely arranged connective tissue with scarce signs of inflammatory reaction. Despite these findings, allografts were free from major structural damage. CONCLUSIONS: The mitral homograft could be an alternative to replacement of the tricuspid valve with a bioprosthesis or a mechanical prosthesis.

The CarboMedics "Top-Hat" supraannular prosthesis.

BACKGROUND: The CarboMedics "Top-Hat" supraannular prosthesis was designed to permit the implantation of a larger prosthesis. METHODS: Between June 1993 and November 1996, 127 patients (average age, 61.8+/-10.2 years) received a CarboMedics "Top-Hat" supraannular aortic prosthesis. The average follow-up was 15.7 months, and all surviving patients underwent echocardiographic study. This group is compared with 656 patients in whom a standard CarboMedics prosthesis was implanted and also with 2,927 patients who received other aortic prostheses. RESULTS: Using the standard and the supraannular sizers, there was an average increase of one size in favor of the supraannular prosthesis: 18.9+/-2.8 mm standard versus 20.8+/-2.6 mm supraannular (p < 0.005). For each prosthesis size (19 to 23 mm), the body surface area of the patients in whom a CarboMedics supraannular prosthesis was implanted was significantly smaller than that in those who received a CarboMedics standard prosthesis or any other model. Hospital mortality was 3.9%, and late mortality was 5.5%. The actuarial survival was 86.5%+/-3.9% at 42 months. CONCLUSIONS: Using the CarboMedics supraannular prosthesis allows implantation of a larger prosthesis compared with the standard CarboMedics prosthesis or other models. This advantage is especially important in patients with a small aortic root.

Durability of the Carpentier-Edwards porcine bioprosthesis: role of age and valve position.

The durability (structural deterioration-free interval) after valve implantation with the first-generation Carpentier-Edwards porcine bioprosthesis has been investigated. From 1978 through 1984, 420 patients (175 male, 245 female) underwent valve replacement with the Carpentier-Edwards standard bioprosthesis. Mean age was 50.6 years (range, 13 to 77 years). Isolated mitral valve replacement (MVR) was performed in 198 patients (47.1%), aortic valve replacement (AVR) in 136 (32.4%), and double valve replacement (DVR) in 86 (20.5%). Hospital mortality was 32 patients (7.6%), 7.5% for MVR, 5.1% for AVR, and 11.6% for DVR. Mean follow-up was 10.8 years (range, 9 to 15 years) and is 96.2% completed. Reoperation for structural deterioration was required in 143 patients. Actuarial curve free from structural deterioration at 15 years is 33.0% +/- 6.5% for MVR, 62.0% +/- 5.1% for AVR, and 44.2% +/- 8.2% for DVR (p < 0.03). Durability of the CE bioprosthesis for MVR was 101.6 +/- 34.5 months, 92.9 +/- 26.4 for AVR, and 84.3 +/- 25.3 for DVR (p = not significant). The regression logistic analysis between age at the time of surgery and durability of the bioprosthesis showed no correlation for the MVR group, but with the following predictive formula for AVR and DVR groups of patients older than 30 years" durability = 46.05 + 0.818 x age, for AVR (r2 = 0.43); durability = 15.81 + 1.122 x age, for DVR (r2 = 0.52). In conclusion, we have found a significant difference in the behavior of the CE porcine bioprosthesis between the mitral and aortic position.(ABSTRACT TRUNCATED AT 250 WORDS)

Open mitral commissurotomy: fourteen- to eighteen-year follow-up clinical study.

From May 1974 to December 1978, 159 patients with mitral stenosis underwent open mitral commissurotomy at our institution. Follow-up data were complete in 96.8%, with a mean follow-up of 13.7 years (range, 14 to 18 years). Preoperatively, most patients (n = 94) were in functional class III or IV. Valve calcification was found in 18 patients (11.3%), left atrial thrombosis was found in 21 (13.2%), and the subvalvular apparatus was affected in 105 (66%). When a residual insufficiency was detected during the operation, a mitral annuloplasty was performed (n = 43). There was one hospital death (0.6%) and 15 late deaths (9.5%). Actuarial survival at 15-year and 18-year follow-up is 89.4% +/- 3% and 75.2% +/- 10.8%. Fifteen patients (9.7%) had a thromboembolic episode 1 to 189 months after operation (mean, 104.3 months). Eleven patients (7%) required reoperation 3 to 183 months after operation (mean, 110.1 months). Freedom from reoperation at 18-year follow-up was 91.9% +/- 2.7%. Event-free actuarial survival at 15-year and 18-year follow-up was 73.4% +/- 4.2% and 54.3% +/- 10.5%. Most patients (n = 131) are in class I or II. Open mitral commissurotomy represents a safe surgical alternative for treating mitral stenosis, allowing a complete removal of atrial thrombosis if present. This long-term follow-up clinical study encourages us to persist in this successful surgical repair of mitral stenosis.

The CarboMedics valve: experience with 1,049 implants.

BACKGROUND: The lack of valve rotatability, the structural deterioration, and the rate of valve-related complications with the standard mechanical bileaflet prosthesis led to the development of a new second-generation bileaflet valve in 1986. METHODS: Between January 1989 and March 1994, 1,049 CarboMedics valves were implanted in 859 patients. The rotatability was used in 109 mitral prostheses (21.5%) and in 61 aortic prostheses (11.6%). Follow-up was 97.1% complete, with 3,049 patient-years. RESULTS: The hospital mortality was 6.9% for the mitral group, 3.4% for the aortic group, and 10.7% for the double-valve group (p < 0.005). The actuarial survival curve at 5 years was 77.3% +/- 3.6%, 90.1% +/- 2.5%, and 79.2% +/- 3.7% (p = 0.0003), freedom from thromboembolism was 89.1% +/- 3.6%, 87.1% +/- 3.8%, and 68.8% +/- 8.2%, freedom from reoperation was 95.9% +/- 1.4%, 98.9% +/- 0.6%, and 94.9% +/- 2.4%, and freedom from valve-related complications was 68.8% +/- 4.1%, 79.5% +/- 3.5%, and 55.3% +/- 5.9% after mitral, aortic, and mitral and aortic valve replacement, respectively. There were five episodes of valve thrombosis, but no structural deterioration occurred. CONCLUSIONS: The clinical performance of the CarboMedics valve is quite satisfactory, with a low incidence of valve-related mortality and morbidity. The rotatability feature was useful when the native valve was preserved or for repeat valve replacement.

Prophylactic resection of a tricuspid valve vegetation in infective endocarditis.

A heroin addict who appeared to have recovered clinically from infective endocarditis of the tricuspid valve as judged by the usual criteria underwent prophylactic resection of a large vegetation on the tricuspid valve in order to prevent severe pulmonary embolism. Prophylactic surgery was justified by the size and as judged by cross-sectional echocardiography of the vegetation and its morphology.

Tricuspid valve replacement in rheumatic disease: preoperative predictors of hospital mortality.

BACKGROUND AND AIM OF THE STUDY: The study analyzes the possible predictive power of different clinical and hemodynamic parameters with regard to hospital mortality after the first tricuspid valve replacement. METHODS: A retrospective study of 62 consecutive patients undergoing tricuspid valve replacement from 1974 to 1994 (7.2% of all tricuspid surgery performed at our institution in this period) was completed. Hospital mortality was 37%. Twenty-three patients died in hospital after the first tricuspid valve replacement (group I) and 39 patients (group II) survived this procedure. Tricuspid insufficiency was organic in 87% of group I and 84.6% of group II. RESULTS: The parameters showing significant differences between the two groups were NYHA class IV (p = 0.05), severe congestive heart failure (p = 0.02), mean right atrial pressure (p = 0.05), pulmonary arterial resistance (p = 0.006) and mean pulmonary arterial pressure (p = 0.0001). Cardiopulmonary bypass time (p = 0.005) and aortic cross-clamp time (p = 0.05) were longer in group I. Multiple regression analysis showed that the variables with greatest predictive power for hospital death were preoperative functional class, congestive heart failure and mean pulmonary artery pressure. The model gave a p < 0.001, with r = 0.58. CONCLUSIONS: The high hospital mortality rate after tricuspid valve replacement seems to be related to clinical functional class, severe congestive heart failure, and to chronic hemodynamic changes in the right atrium and pulmonary circulation.

Reoperation for bioprosthetic valve dysfunction. A decade of clinical experience.

During the 1970s, initial clinical experience with bioprostheses determined their worldwide use. However, bioprosthetic reoperation (BPR) is now common, particularly in groups with extensive implantation of these valve substitutes. From January 1980 to December 1989, a total of 470 patients had a total of 618 reoperations for bioprosthetic dysfunction and were retrospectively analyzed. Eighty-seven patients required a second BPR, 21 a third BPR, 5 a fourth BPR and 1 patient a fifth BPR. Structural deterioration was the main cause of valve dysfunction for the first and second BPR. However, paravalvular leak and infective endocarditis were more frequent for the remaining additional reoperations. Hospital mortality was 12.6%, 14.9% and 37% after the first, second and third or subsequent BPR, respectively. Univariate statistical analysis shows as hospital mortality risk factors: age at the time of the surgery, preoperative NYHA functional class IV, emergency surgery, concomitant tricuspid surgery, double (mitro-aortic) valve dysfunction, active infective endocarditis as the cause of failure and prolonged aortic cross-clamping time. Hospital mortality declined from 19.8% to 11.8% for the first and second half decade, respectively (P less than 0.005). In conclusion, bioprosthetic valve reoperation entailed a higher hospital mortality, particularly in the risk group of patients. In our hands, surgical experience has determined the improvement of the clinical results in this group of patients.

Gastropexy simplifies the use of the right gastroepiploic artery for myocardial revascularization.

Surgical anterior and superior fixation to the diaphragam of a segment of the greater curvature of the stomach simplifies the technical performance of harvesting the right gastroepiploic artery for coronary bypass grafting. Gastropexy avoids objections to the use of this pedicled arterial graft, such as the prolonged dissection time, the limited length of the conduit and the potential damage when abdominal surgery is later required.

Assessment of the diagnostic capacity of planar scintigraphy and SPECT with 99mTc-HMPAO-labelled leukocytes in superficial and deep sternal infections after median sternotomy.

Sternal infection is a rare complication of median sternotomy but is associated with considerable morbidity and mortality, particularly in the case of deep sternal infection (mediastinitis). Successful treatment depends on early diagnosis and on the location (deep or superficial) of the infection. Radiological techniques have many limitations, and although 67Ga scintigraphy is effective, it delays diagnosis by 48 h. We assessed the diagnostic capacity of planar scintigraphy and single photon emission computed tomography (SPECT) with 99mTc-hexamethylpropylene amine oxime (HMPAO)-labelled leukocytes in deep sternal infections after median sternotomy. We prospectively studied 41 patients with clinical suspicion of deep sternal infection 4 and 20 h after administration of the tracer. The final diagnosis was deep sternal infection in nine patients and superficial sternal infection in 10, with infection being ruled out in 22 patients. Planar scintigraphy did not detect any of the deep sternal infections at either 4 h or 20 h. SPECT correctly identified eight of the nine deep sternal infections at 4 h and all seven at 20 h, with no false positive results. Planar scintigraphy identified 16 of the 18 superficial sternal infections at 4 h and all of them at 20 h. SPECT identified 17 of these 18 infections at 4 h and all of them at 20 h. Other infections unrelated to the sternotomy were identified in seven patients. Leukocytes labelled with 99mTc-HMPAO are a highly reliable method for the early diagnosis of sternal infections after median sternotomy. Use of SPECT allows determination of the depth of the infection and differentiation of superficial from deep sternal infections. It is also possible to detect other sites of infection, thus providing alternative diagnoses.

Planar scintigraphy and SPET with 99Tcm-HMPAO-labelled leukocytes in patients with median sternotomy: normal patterns.

The aim of this study was to determine the normal planar and SPET patterns of the thoracic distribution of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) in 20 patients who had undergone a previous median sternotomy and without infectious complications at follow-up. The study included anterior and oblique anterior planar views at 4 and 20 h. SPET of the chest was also carried out at 4 and 20 h. At 4 h, the planar views showed low background vascular activity in the lungs and cardiac region in addition to the sternal uptake, which showed two patterns: homogeneous in five patients and heterogeneous in 15. A long and narrow defect of uptake along the sternal midline was the most characteristic finding. At 4 h, in addition to the background vascular activity in the lungs and cardiac region, the greatest uptake on SPET was in the sternum anteriorly and the marrow spine posteriorly without any focal uptake, allowing visualization of the mediastinum free of focal activity. At 20 h, both the planar and SPET images showed a higher organ-to-background ratio. Knowledge of these post-surgical patterns will make it easier to interpret planar and SPET images when 99Tcm-HMPAO-labelled leukocytes are used in the diagnosis of mediastinitis and sternal infections in patients who had previously undergone median sternotomy. Planar views were better for the assessment of sternal uptake, but SPET views were better for the direct visualization of the mediastinum by eliminating overlapping sternal uptake.