A rare case of Clostridium paraputrificum bacteremia in a 78-year-old Caucasian man diagnosed with an intestinal neoplasm.

Clostridium like species, particularly Clostridium perfrigens, are the second most common causes of human anaerobic infections, including myonecrosis and bacteremia. Clostridium paraputrificum is an infrequent isolate, which has been identified in only 1% of reported cases of clostridial infections. We herein report a rare case of C. paraputrificum bacteremia in a 78-year-old Caucasian man diagnosed with an intestinal carcinoma and liver neoplastic lesions. The isolate was susceptible to chloramphenicol, meropenem, metronidazole, vancomycin, and resistant to clindamycin and penicillin, and the patient was successfully treated with metronidazole. Malignancy and inflammatory bowel diseases are often associated with clostridial bacteremia, which cannot be neglected.

Survey on the interest and commitment of AIFM members to scientific activities (SicAS) - The initiative of the FutuRuS working group.

PURPOSE: The "FutuRuS" working group of the Italian Association of Medical Physics and Health Physics (AIFM) designed a survey (SicAS) to get feedback from its members regarding their interests and their experience in taking part in scientific activities and events, with the objective of focusing future efforts of the AIFM towards increasing the scientific activity of the medical physics expert (MPE). METHODS: SicAS was sent out in March 2022 to all AIFM members by newsletter and official communication. SicAS was structured into three sections: personal information and institution of affiliation information, involvement in scientific activities, interest in and commitment to scientific activities. Responses were collected in a fully anonymised mode from the Google Forms platform and analysed with descriptive statistics. RESULTS: Out of 1289 members (active at the end of 2021), 467 responded to the Survey (response rate of 36%). The Survey results highlighted that AIFM members ranked the involvement of the MPE in scientific activities as highly relevant to the profession. However, 34.7% indicated devoting less than 10% of their working time to scientific activities. 67.5% of the respondents were dissatisfied with the time spent on scientific activities. The primary barrier was the lack of time (77%), followed by a lack of mentoring (32%). CONCLUSIONS: SicAS highlighted the need for AIFM initiatives to support members' scientific activities. National societies should help develop and support networks between members, create links among universities, hospitals, research institutions and industries, and provide guidelines and learning platforms for enhancing the MPEs' involvement in scientific activities.

Strengthening preparedness against global health threats: A paradigm shift based on One Health approaches.

The implementation of preparedness strategies to prevent and mitigate the impact of global health threats poses several challenges. It should promptly identify cross-cutting drivers of pandemic threats, assess context-specific risks, engage multiple stakeholders, and translate complex data from multiple sources into accessible information for action. This requires a coordinated, multidisciplinary and multisectoral effort engaging systems that, most of the time, work in isolation. The One Health (OH) approach promotes the collaboration and communication among different disciplines and sectors, and could be applied across the preparedness phases at national and international level. We discuss here gaps and needs in preparedness strategies, which can benefit from the OH approach, and a set of actionable recommendations, as shared with the G20-2021 with a dedicated Policy Brief. The discussion adds to the current debate about OH operationalization and promotes a paradigm shift towards coordinated prevention and preparedness strategies for early assessment and management of global health threats.

No difference between supine and prone position for ERCP in conscious sedated patients: a prospective randomized study.

BACKGROUND AND AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is usually performed with the patient prone or in the left lateral position. The supine position could be more comfortable and may facilitate airway management. On the other hand, technical difficulties and a greater risk of adverse cardiorespiratory events have been shown when ERCP is performed in a supine patient. Our aim was to assess, in a tertiary referral center, the differences between performing ERCP with the patient supine or prone, in terms of technical features and complications both during and after the procedure. PATIENTS AND METHODS: Between December 2005 and May 2006, 120 patients (66 female, mean age 62 years) who had an intact papilla and were candidates for therapeutic ERCP were prospectively randomized to undergo ERCP under conscious sedation with midazolam, in the prone (n = 60) or supine (n = 60) position, by an expert endoscopist (tutor) or a trainee. The following parameters were recorded: difficulty of cannulation and difficulty of ECRP procedure, time needed to visualize the papilla, time needed to achieve opacification and cannulation, exam duration, episodes of tachy/bradycardia and desaturation, episodes of duodenoscope displacement into the stomach, and complications. RESULTS: Ninety-eight patients underwent ERCP for benign disease and 22 for malignant biliary strictures. The ERCP success rate was 98.3 % in the tutor group and 43.3 % in the trainee group. No significant differences were found between the two groups of operators (tutors and trainees) in the recorded parameters and complication rates encountered in prone versus supine patients. CONCLUSION: Our results show that ERCP success rates and complications (intraoperative and postoperative) are similar whether ERCP is performed with the patient prone or supine, even when operators are of differing skill levels. Training, technique, and a proper learning phase are recommended in order to perform ERCP with no differences whether the patient is prone or supine.

Eosinophilic esophagitis is a component of the anticonvulsant hypersensitivity syndrome: description of two cases.

Anticonvulsant hypersensitivity syndrome is a rare syndrome caused by a specific, severe unusual reaction to antiepileptic agents; anticonvulsant hypersensitivity syndrome develops 1 week to 3 months after the introduction of the drug and most frequently consists of a multisystemic and multiorgan involvement. Drug withdrawal usually leads to rapid improvement of symptoms. Up to now no oesophageal damage has been described. We present two cases of carbamazepine hypersensitivity syndrome with concomitant development of eosinophilic oesophagitis that resolved after drug withdrawal.

Hancock II porcine bioprosthesis: excellent durability at intermediate-term follow-up.

OBJECTIVES: This study aimed to assess the clinical performance and durability of a new generation of porcine valve, the Hancock II bioprosthesis, at intermediate-term follow-up. BACKGROUND: Standard porcine bioprostheses undergo progressive structural deterioration, mainly due to cusp and commissural calcification, affecting durability and requiring reoperation. The Hancock II bioprosthesis, which is currently undergoing clinical investigation, is made from a porcine aortic valve treated with a calcium-retarding agent (sodium dodecyl sulfate [T6]), which should delay onset of calcification and increase durability. METHODS: From May 1983 to December 1992, we used the Hancock II bioprothesis in aortic (59 patients), mitral (101 patients) and mitral-aortic (25 patients), valve replacement procedures. Postoperative follow-up ranged from 0.1 to 8.7 years (mean [+/- SD] 4.5 +/- 2.6 years) and was 100% complete. Freedom from major postoperative events was calculated at 7 years for patients with aortic valve replacement and at 8 years for those with mitral and mitral-aortic valve replacement. RESULTS: The actuarial survival rate was 48 +/- 10%, 76 +/- 3% and 63 +/- 6%; freedom from valve-related mortality was 91 +/- 4%, 94 +/- 2% and 89 +/- 6%; freedom from thromboembolism was 80 +/- 11%, 90 +/- 2% and 79 +/- 7%; and freedom from reoperation was 100%, 97 +/- 1% and 89 +/- 6% after aortic, mitral and mitral-aortic valve replacement, respectively. No structural valve deterioration occurred. CONCLUSIONS: At intermediate-term follow-up the Hancock II bioprosthesis showed excellent durability in all positions. However, the effectiveness of anticalcification treatment must be assessed with longer follow-up studies.

Wireless capsule endoscopy in the diagnostic of small intestine angiodysplasia in chronic uremic patient.

Gastroenteric bleeding due to angiodysplasia (AD) is a relatively common occurrence in patients with end-stage renal failure. Gastric and colon angiodysplasic lesions can be easily revealed by endoscopic procedures, whereas lesions of the small intestine are more difficult to detect. Imaging modalities used in the diagnostic imaging algorithm for the detection of small-bowel AD, include non-invasive methods like enema-helical computer tomography,(99m)Tc-labelled red blood cell scintigraphy, and angiography, and invasive methods such as intraoperative enteroscopy. We report the cases of 3 hemodialysis patients with recurrent episodes of gastrointestinal bleeding, caused by small-bowel AD diagnosed by means of wireless-capsule endoscopy. In all cases, previous gastroscopy and colonoscopy were unrevealing. Wireless-capsule endoscopy consists in swallowing a capsule endoscope (11 mmx27 mm) which contains a miniature video camera, a light source, batteries, and a radio transmitter. Video images are transmitted by means of radio telemetry to aerials taped to the body that allow images to be captured. Moving images from a period as long as 6 h are stored on a portable recorder. Wireless-capsule endoscopy may prove valuable in the assessment of gastrointestinal bleeding in uremic patients with unrevealing results at gastroscopy and colonoscopy.

[Angiodysplasia of the small bowel: a possible cause of anemia even in mild chronic renal failure]. / Angiodisplasia dell'intestino tenue: una possibile causa di anemizzazione nell'IRC anche di grado lieve.

BACKGROUND: Gastroenteric angiodysplasia (AD) is a vascular lesion characterized by vascular ectasias to the submucous sheath of the gastrointestinal tract. Lesions can be flat or raised, isolated or grouped and can break or ulcerate causing acute hemorrhage or, more commonly, chronic bleeding. CASE-REPORT: We describe a 65-year-old patient with a 3-yr history of chronic renal failure (CRF), who gradually developed anemia (hemoglobin (Hb) 10 g/dl) without any episodes of clinically relevant bleeding or any exposure to bleeding risk factors. Blood pressure (BP) was normal and renal function was stable (serum creatinine (Cr) 1.9 mg/dl). Routine laboratory tests showed a slight reduction in serum iron and transferrin saturation and a slightly elevated absolute reticulocyte count. These findings were associated with a positive occult gastrointestinal blood test and raised the clinical suspicion of chronic gastrointestinal blood loss. Oesophagogastro-duodenoscopy and colonoscopy demonstrated an absence of significant lesions, suggesting the need to investigate for a lesion localized in the small intestine. Capsular endoscopy, a recently developed endoscopic technique, particularly suited for small bowel pathology, was performed, and demonstrated the presence of an angiodysplasic lesion, located in the jejunum. CONCLUSIONS: Our case report supports the necessity for a complete clinical and laboratory evaluation of the possible causes of anemia superimposed on relative erythropoietin deficiency in CRF patients. When gastrointestinal blood loss is suspected, the entire gastroenteric tract should be examined to search for the bleeding sites. Our report also demonstrates that AD could be responsible for gastrointestinal bleeding even in mild CRF and not only, as usually reported, in end-stage renal disease (ESRD). Capsular endoscopy offers the unique possibility to determine the bleeding site in the small intestine and appears as an effective diagnostic procedure in CRF patients.

Sequence of the gene encoding an alkaline serine protease of thermophilic Bacillus smithii.

The complete nucleotide sequence of the gene encoding an alkaline serine protease from Bacillus smithii has been determined. Degenerate oligodeoxyribonucleotide primers were used to prime the amplification of a 507-bp sequence of the gene. This sequence was successively used for constructing new primers applied in inverse polymerase chain reaction, using as template self-ligated DNA fragments. The deduced amino-acid sequence is compared to serine proteases from B. amyloliquefaciens, B. licheniformis, B. subtilis and Thermus aquaticus.

The TB structural genomics consortium: a resource for Mycobacterium tuberculosis biology.

The TB Structural Genomics Consortium is an organization devoted to encouraging, coordinating, and facilitating the determination and analysis of structures of proteins from Mycobacterium tuberculosis. The Consortium members hope to work together with other M. tuberculosis researchers to identify M. tuberculosis proteins for which structural information could provide important biological information, to analyze and interpret structures of M. tuberculosis proteins, and to work collaboratively to test ideas about M. tuberculosis protein function that are suggested by structure or related to structural information. This review describes the TB Structural Genomics Consortium and some of the proteins for which the Consortium is in the progress of determining three-dimensional structures.

Extracorporeal photochemotherapy as adjuvant treatment of heart transplant recipients with recurrent rejection.

Recurrent rejection is an uncommon, severe complication after heart transplantation that is associated with a poor long-term prognosis. Photopheresis (ECP), a new form of extracorporeal photo-chemotherapy used for the treatment of cutaneous T cell lymphoma and several autoimmune diseases, has also been used for prevention and treatment of acute rejection in heart transplant recipients. It seems to induce specific suppression of both cellular and humoral rejection. In this study, we evaluated whether ECP added to standard therapies allowed better control of rejection and reduction of conventional immunosuppressive drugs in patients with repeated rejection episodes. Eight heart transplant recipients (6 men and 2 women, mean age 48 yr), with recurrent rejection were treated with ECP for 6 months. Endomyocardial biopsies (EMB) were performed monthly. As a result of treatment, 7 patients on ECP experienced a reduction of the number and severity of rejection episodes. The fraction of EMB negative for rejection increased from 13 to 41%, whereas the fraction of specimens with multifocal and/or diffuse moderate lymphocytes infiltration (grades 3A and 3B) decreased from 41 to 21%. ECP allowed reductions of daily immunosuppressive therapy: prednisone by 44% (16.9 vs. 9.4 mg), cyclosporine by 21% (366 vs. 291 mg), and azathioprine by 29% (137 vs. 97 mg). No major side effects were observed. We conclude that, although the number of patients is small, the use of ECP was safe and associated with improved control of recurrent rejection. This allowed tapering of immunosuppressive drugs, which was particularly useful in two patients with insulin-dependent diabetes and one with sternal wound osteomyelitis.

Transmyocardial laser revascularization using a thoracoscopic approach.

Transmyocardial revascularization is a new technique aimed to improve perfusion of the ischemic myocardium by creating transmyocardial channels with a laser. This report demonstrates that transmyocardial revascularization with a holmium laser can be performed through a thoracoscopic approach.

Pregnancy in patients with a porcine valve bioprosthesis.

Seven patients who became pregnant after valve replacement with a Hancock bioprosthesis were followed up during 8 pregnancies. Six had undergone isolated mitral valve replacement, and 1 had mitral and aortic valve replacement. Their age at the time of operation ranged from 14 to 31 years (average 24); delivery occurred 21 to 88 months (average 51.3) after valve replacement. All women were in sinus rhythm at the time of gestation, and administration of oral anticoagulants was avoided in all. No embolic episodes occurred either after operation or during pregnancy, labor, or puerperium. The only major complication during pregnancy was cardiac failure in 1 patient, associated with onset of atrial fibrillation. Four women had vaginal delivery and 3 required cesarean section. All but 1 delivered a normal, healthy baby. One premature infant died soon after birth because of respiratory distress. No maternal or fetal hemorrhagic complications were observed. One patient died 3 months after delivery in severe heart failure caused by diffuse calcification of both mitral and aortic xenografts. Another women underwent successful reoperation soon after the second pregnancy because of calcific stenosis of the mitral porcine valve. It is concluded that (1) bioprosthetic valves can be considered the most suitable devices employed in women of childbearing age because anticoagulants can be avoided, therefore eliminating the risks related to inappropriate administration of oral anticoagulants as well as the hazards associated with the potential teratogenic effect of coumarin drugs; and (2) pregnancy might favor calcification of porcine heterografts, leading to bioprosthetic failure. Until further data are available to support this suspicion, close clinical and echocardiographic follow-up study of these patients is recommended after pregnancy.

Calcific degeneration as the main cause of porcine bioprosthetic valve failure.

Sixty-seven glutaraldehyde-processed porcine bioprostheses (PBs), recovered at autopsy or reoperation from 65 patients, were evaluated by roentgenologic and pathologic examination. Seven patients with 8 PBs were younger than 20 years of age. The time interval of function was 2 to 138 months (average 62). Pathologically, 53 explants had signs of intrinsic dysfunction, which was ascribed to calcification in 36 (68%). By x-ray examination, calcific deposits were found in 55 of 67 PBs (82%). The mean duration of function was 70 +/- 32 months in calcified PBs vs 27 +/- 18 months in noncalcified PBs (p less than 0.001). All 26 PBs that had been in place for longer than 6 years were calcified. In 45 PBs the Ca++ deposits were considered severe (mean time of function 76 +/- 32 months) and mild in 10 (mean time of function 44 +/- 22 months) (p less than 0.005). The Ca++ deposits were located at the commissures in 54 PBs (98%), at the body of cusps in 41 (75%), at the free margin in 37 (67%) and at the aortic wall in 37 (67%). When mild, Ca++ deposits involved the commissures in 90% of cases, the body of cusps in 30% and the free margin only in 10%. Forty-seven calcified PBs were mounted on a flexible stent, and 8 had a rigid stent, with an average time of function of 63 +/- 28 and 113 +/- 18 months, respectively (p less than 0.00001). Ca++ dysfunction occurred earlier in the aortic than in the mitral position (59 +/- 19 vs 86 +/- 35 months, p less than 0.05). All the PBs explanted from young patients and 47 of 59 PBs removed from adult patients were calcified, with an average time of function of 50 +/- 21 vs 73 +/- 33 months, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Role of antibiotic sensitivity testing before first-line Helicobacter pylori eradication treatments.

BACKGROUND: The resistance of Helicobacter pylori to antibiotics has been advocated as a major cause of treatment failure, and antimicrobial sensitivity testing has been proposed to improve efficacy; however, its role before first-line therapy has not been investigated in detail. AIM: To assess whether antimicrobial sensitivity testing improves the eradication rate of first-line anti-Helicobacter treatments and to compare the effectiveness of ranitidine bismuth citrate and omeprazole in the presence of H. pylori resistance to antibiotics. METHODS: Two hundred and forty-two patients were assigned to either empirical or antimicrobial sensitivity testing-based treatment; within each group, subjects were further randomized to receive ranitidine bismuth citrate, 400 mg b.d., tinidazole, 500 mg b.d., and clarithromycin, 500 mg b.d., or omeprazole, 20 mg b.d., clarithromycin, 500 mg b.d., and amoxicillin, 1 g b.d., for 1 week, with substitution of the resistant antibiotic in the antimicrobial sensitivity testing-based treatment group. RESULTS: Eradication rates were 67% [confidence interval (CI), 55-79%] in the empirical treatment group and 76% (CI, 65-87%) in the antimicrobial sensitivity testing-based group (P=N.S.). The overall success rate was 60% (CI, 51-69%) with omeprazole and 82% (CI, 73-91%) with ranitidine bismuth citrate (P<0.03); the latter overcame antibiotic resistance in 12 of 15 strains vs. zero of eight strains by omeprazole. CONCLUSIONS: Antimicrobial sensitivity testing before first-line treatment does not improve the eradication rate, which is greater when ranitidine bismuth citrate is included in the treatment.

Results of reoperation for primary tissue failure of porcine bioprostheses.

Results of reoperation for primary tissue failure of porcine bioprostheses were evaluated in 574 patients discharged from the hospital from 1970 to 1981. A total of 413 had undergone isolated mitral valve replacement and 161 isolated aortic valve replacement. Through March, 1984, 88 patients (15%) had required reoperation: 59 had undergone mitral and 29, aortic valve replacement. Primary tissue failure was the main cause of bioprosthetic dysfunction; it occurred in 64 patients (46 mitral and 18 aortic) at a mean postoperative interval of 93 +/- 4 months (range 34 to 158). During the same period, 11 patients required reoperation for bioprosthetic endocarditis, 11 for paravalvular leak, and two for thrombosis. These patients are not included in this review. Reoperation for primary tissue failure was performed after a mean interval of 72 +/- 6 months (range 38 to 158) for patients with aortic bioprostheses and after 101 +/- 5 months (range 34 to 153) for those with mitral bioprostheses (p less than 0.05). Overall mortality at reoperation was 12.5%: 11% for the mitral group and 16% for the aortic group. In 62 patients (45 mitral and 17 aortic) primary tissue failure was caused by calcification of the cusps, associated with severe fibrous tissue overgrowth in seven. Bioprosthetic failure was caused by an intracuspal hematoma in one patient with mitral valve replacement and by lipid infiltration of the cusps in one patient with aortic valve replacement. Actuarial freedom from bioprosthetic primary tissue failure at 12 years is 61% +/- 5% for the mitral group and 69% +/- 7% for the aortic group. On the basis of our long-term follow-up of patients after mitral or aortic replacement with a porcine bioprosthesis, we conclude: primary tissue failure is the most frequent indication for reoperation in patients with a porcine bioprosthesis; calcification of the cusp tissue is the leading cause of primary tissue failure; reoperation for primary tissue failure may be a major concern, although mortality for elective cases is low; and the limited durability of porcine bioprostheses suggests their use be restricted to selected patients.

Fatal obstruction of the left ventricular outflow tract caused by low-profile bioprostheses in the mitral valve position.

Two cases of fatal left ventricular outflow tract obstruction following mitral valve replacement with low-profile bioprostheses are described. This unfortunate experience shows that correct orientation of the prosthesis is mandatory also when using low-profile bioprosthetic valves to avoid this complication, particularly in patients with a small left ventricular cavity.

Long-term performance of the Hancock porcine bioprosthesis in the tricuspid position. A review of forty-five patients with fourteen-year follow-up.

Because little information is available regarding the clinical performance of the Hancock porcine bioprosthesis (Johnson & Johnson Cardiovascular, King of Prussia, Pa.) implanted in the tricuspid position, we reviewed the long-term follow-up of patients who had tricuspid valve replacement with this device. From March 1970 to December 1983, 45 patients had tricuspid valve replacement, either isolated (seven patients) or combined with replacement of other valves (38 patients) by means of a standard, glutaraldehyde-preserved Hancock porcine bioprosthesis. Follow-up ranged from 0.2 to 14.7 years (mean, 7.6 +/- 3.6 years) and was complete. The late mortality rate was 6.6% +/- 1.6%/pt-yr and the actuarial survival rate at 14 years was 23% +/- 9%. Reoperation because of structural deterioration of the tricuspid, the mitral, or both bioprostheses was performed in nine patients (3.7% +/- 1.2%/pt-yr) from 40 to 177 months (mean, 112 +/- 43 months) and resulted in no deaths. Actuarial freedom from structural deterioration of a Hancock tricuspid porcine bioprosthesis at 14 years is 68% +/- 13%. Morphologic examination of explanted porcine bioprostheses showed that those implanted in the tricuspid position had lower degrees of calcification and less severe structural changes than those simultaneously explanted from the mitral position. We conclude that the Hancock porcine bioprosthesis has an acceptable long-term durability and satisfactory performance after tricuspid valve replacement, and we continue to favor its use in the tricuspid position even in association with mechanical prostheses in the left side of the heart.

Aortic valve replacement with the Hancock standard, Björk-Shiley, and Lillehei-Kaster prostheses. A comparison based on follow-up from 1 to 15 years.

Three series of patients undergoing isolated aortic valve replacement with the standard glutaraldehyde-preserved Hancock porcine bioprosthesis, the standard Björk-Shiley spherical disc prosthesis, and the Lillehei-Kaster tilting disc prosthesis were compared during a 15-year follow-up. From March 1970 to December 1985, aortic valve replacement was performed in 506 patients, 379 men and 109 women, whose ages ranged from 17 to 71 years (mean, 47 +/- 12 years); 196 had a Hancock bioprosthesis, 147 a Björk-Shiley prosthesis, and 163 a Lillehei-Kaster prosthesis. There were no significant differences among the three groups in terms of mean age, preoperative New York Heart Association class, valve lesion, associated intracardiac procedures, and operative mortality (11.7% for the Hancock bioprosthesis group, 8.8% for the Björk-Shiley prosthesis group, and 9.2% for the Lillehei-Kaster prosthesis group). Cumulative duration of follow-up is 1140 patient-years (mean, 6.6 +/- 1.5 years, 100% complete) for Hancock bioprosthesis patients, 878 patient-years (mean, 5.9 +/- 0.4 years, 98% complete) for Björk-Shiley prosthesis patients, and 1184 patient-years (mean, 7.3 +/- 0.3 years, 97% complete) for Lillehei-Kaster prosthesis patients. Actuarial survival rates at 15 years are 30% +/- 15% for Hancock bioprosthesis, 49% +/- 6% for Björk-Shiley prosthesis, and 44% +/- 7% for Lillehei-Kaster prosthesis patients. There were eight embolic episodes in Hancock valve recipients (0.7% +/- 0.1%/pt-yr), nine in Björk-Shiley prosthesis recipients (1.0% +/- 0.3%/pt-yr), and nine (0.7% +/- 0.1%/pt-yr) in Lillehei-Kaster prosthesis recipients (p = no significant difference). Actuarial freedom from emboli at 15 years is 89% +/- 4% for Hancock, 92% +/- 3% for Björk-Shiley, and 93% +/- 2% for Lillehei-Kaster prosthesis recipients (p = no significant difference). A significant difference was found in the incidence of the following complications. (1) Anticoagulant-related hemorrhage: 0.1% +/- 0.1%/pt-yr for Hancock bioprosthesis, 1.3% +/- 0.3%/pt-yr for Björk-Shiley prosthesis, and 1.9% +/- 0.4%/pt-yr for Lillehei-Kaster prosthesis patients (p less than 0.001), with an actuarial freedom at 15 years of 97.6% +/- 1% for Hancock, 85% +/- 5% for Björk-Shiley, and 68.8% +/- 10% for Lillehei-Kaster recipients (p less than 0.001). (2) Structural deterioration: 3.7% +/- 0.6%/pt-yr for Hancock and none for Björk-Shiley and Lillehei-Kaster patients (p less than 0.001), with an actuarial freedom of 100% for Björk-Shiley prosthesis and Lillehei-Kaster prosthesis patients and 38.4% +/- 12% for Hancock bioprosthesis patients at 15 years.

Early mechanical failures of the Hancock pericardial xenograft.

From August 1981 to July 1984, a total of 97 Hancock pericardial xenografts were implanted in 84 patients, whose ages ranged from 13 to 75 years (mean 55.7 +/- 13). Mitral value replacement was performed in 17, aortic valve replacement in 54, and mitral-aortic valve replacement in 13. Operative survivors were reevaluated from July to September 1985. Cumulative duration of follow-up is 167 patient-years (range 0.5 to 4.1 years), and follow-up is 99% complete. The overall late mortality (at 4 years) is 3.6% +/- 1.4% per patient year, and the actuarial survival rate is 95.4% +/- 3% for aortic valve replacement, 74.7% +/- 16.5% for mitral valve replacement, and 67.1% +/- 20.7% for mitral-aortic valve replacement. One patient sustained a thromboembolic event after mitral valve replacement, but no such complications occurred after aortic or mitral-aortic valve replacement. Actuarial freedom from embolism at 4 years is 100% for aortic and mitral-aortic valve replacement and 93.3% +/- 6.4% for mitral valve replacement. Reoperation for Hancock pericardial xenograft dysfunction was performed in seven patients (five aortic and two mitral-aortic). In the aortic valve replacement group the causes were endocarditis in one, paravalvular leak in one, and primary tissue failure in three; all survived reoperation. The two patients with mitral-aortic valve replacement required reoperation because of primary tissue failure of both Hancock pericardial xenografts, and one died. All values explanted because of primary tissue failure showed commissural tears causing severe prosthetic regurgitation. Calcium deposits were severe in one and mild but unrelated to the cusp rupture in another. Collagen disarray was seen only at the site of the tears, whereas the collagen structure was well preserved in the intact parts of the cusps. Four patients with aortic valve replacement and one with mitral valve replacement show evidence of Hancock pericardial xenograft failure and are awaiting reoperation. The actuarial freedom from primary tissue failure at 4 years is 74.3% +/- 9.8% for aortic and 78.9% +/- 13.2% for mitral Hancock pericardial xenografts. At medium-term follow-up, the Hancock pericardial xenograft has shown poor durability and an extremely high rate of early mechanical failure, especially in the aortic position. These observations suggest the need for a close follow-up of Hancock pericardial xenograft recipients and possibly elective reoperation in asymptomatic patients with clinical evidence of prosthetic failure. These results have led us to discontinue the clinical use of this pericardial xenograft.