Which manufacturing characteristics are predictors of outlet strut fracture in large sixty-degree Björk-Shiley convexo-concave mitral valves? The Björk-Shiley Study Group

BACKGROUND: Identification of predictors of outlet strut fracture is important for recipients of large (>/=29 mm) 60-degree Bj?rk-Shiley convexo-concave mitral valves when it comes to decision making on prophylactic explantation. An association between the manufacturing process of Bj?rk-Shiley convexo-concave valves and the risk of fracture has been suggested. OBJECTIVE: The aim of this study was to determine which items from the manufacturing records, in addition to known risk factors, were predictive of fracture of large 60-degree Bj?rk-Shiley convexo-concave mitral valves. METHODS: All Dutch recipients (n = 2264) of Bj?rk-Shiley convexo-concave valves were followed up until fracture, death, reoperation, or end of the study (July 1, 1996). Information was abstracted from the manufacturing records of large 60-degree Bj?rk-Shiley convexo- concave mitral valves (n = 655) in Dutch recipients and included items that described the manufacturing process and items for which an association with strut fracture had been suggested. Manufacturing records were available for 637 valves (97%), including 25 fractured valves. RESULTS: Multivariate analysis identified age at implantation (hazard ratio 0.95, 95% confidence interval 0.93-0.97), lot size (<175 valves versus >/=175 valves; hazard ratio 6.6, 95% confidence interval 2.2-20.1), number of hook deflection tests performed (0 or 1 versus >/=2; hazard ratio 4.7, 95% confidence interval 1.4-16.2), number of disks that were used (1 versus >/=2; hazard ratio 5.9, 95% confidence interval 1.9-18.5), and lot fracture percentage (hazard ratio 1.6, 95% confidence interval 1.4-1. 8) as independent predictors of fracture. Although the added predictive value of a model with these 5 variables was sizable compared with a model containing age only, it was only slightly better than a model with age, lot size, and lot fracture percentage. CONCLUSION: If the serial number of a large 60-degree Bj?rk-Shiley convexo-concave mitral valve is known, manufacturing information can add significantly to the prediction of fracture. Information on lot size and lot fracture percentage should be made available to clinicians for risk assessment of prophylactic explantation.     

Survival and reoperation pattern after 20 years of experience with aortic valve–sparing root replacement in patients with tricuspid and bicuspid valves

Objective

Remodeling or reimplantation are established operative techniques of aortic valve–sparing root replacement. Long-term follow-up is necessary comparing tricuspid and bicuspid aortic valves.

Outlet strut fracture of Björk-Shiley convexo-concave valves: can valve-manufacturing characteristics explain the risk?

BACKGROUND: Bj?rk-Shiley 60 degrees convexo-concave prosthetic heart valves (Shiley, Inc, Irvine, Calif, a subsidiary of Pfizer, Inc) continue to be a concern for approximately 35,000 nonexplanted patients worldwide, with approximately 600 events reported to the manufacturer to date. Fractures of the outlet struts of the valves began to appear in the early 1980s and have continued to the present, but their causes are only partially understood. METHODS: A matched case-control study was conducted evaluating manufacturing records for 52 valves with outlet strut fractures and 248 control subjects matched for age at implantation, valve size, and valve position. RESULTS: In addition to the risk factors recognized as determinants of outlet strut fracture, the United Kingdom case-control study has observed 7- to 9-fold increased risk with performance of multiple hook deflection tests. This test was performed more than once, usually after rework on the valve. Six valves in this study underwent multiple hook deflection tests, of which 4 experienced an outlet strut fracture. Cracks and further rework were noted for these valves. Significant associations were also observed between outlet strut fracture and disc-to-strut gap measurements taken before the attachment of the sewing ring. CONCLUSIONS: It is our view that a combination of factors related to valve design, manufacturing process, and patient characteristics are responsible for outlet strut fractures of Bj?rk-Shiley convexo-concave valves. Multiple hook deflection tests have emerged as a potential new risk factor for outlet strut fracture in both The Netherlands and the United Kingdom. This factor appears to be correlated with the presence of other abnormalities. A further study is needed to investigate the factors correlated with multiple hook deflection tests. On confirmation of risk, the presence of multiple hook deflection tests may be added to equations, quantifying the risk of outlet strut fracture for comparison against risk of mortality and serious morbidity from explant operations.     

Are older patients with mechanical heart valves at increased risk?

Background. Controversy exists regarding the use of mechanical valves in older patients. Many authorities believe that the use of anticoagulants in the elderly is associated with an increased risk of warfarin-related complications. Therefore, we compared the results with mechanical valves in older patients to a cohort of younger patients.

Methods. Aortic (AVR) or mitral valve replacement (MVR) with a mechanical valve was performed in 1,245 consecutive patients who were followed prospectively. They were grouped by age (group 1, ≤ 65 years; group 2, > 65 years). The study groups consisted of AVR (group 1, 459 patients; group 2, 323 patients) MVR (group 1, 313 patients; group 2, 150 patients).

Results. The average age for the groups was: AVR (group 1, 51 years; group 2, 70 years; p = 0.03) and MVR (group 1, 53 years; group 2, 70 years; p = 0.03). For AVR the incidence of thromboembolism was 0.050 (group 1) and 0.038 (group 2) (p = 0.37) and the actuarial freedom from thromboembolism was 83.0% ± 3.0% and 86.5% ± 1.0%, respectively (p = 0.13). The incidence of bleeding after AVR was 0.021 for group 1 and 0.028 for group 2 (p = 0.49). For MVR the incidence of thromboembolism was 0.059 for group 1 and 0.051 for group 2 (p = 0.75) and the actuarial freedom from thromboembolism was 78.8% ± 3.0% and 75.4% ± 8.7%, respectively (p = 0.71). The incidence of bleeding after MVR was 0.020 for group 1 and 0.027 for group 2 (p = 0.62).

Conclusions. Mechanical valves perform well in selected older patients with no increased risk of bleeding or thromboembolism.     

Is addition of anti-platelet therapy to warfarin beneficial to patients with prosthetic heart valves?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether addition of anti-platelet therapy to warfarin reduced the incidence of thromboembolic complications in patients with prosthetic heart valves. Altogether 253 papers were found using the reported search, of which 11 papers represented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses were tabulated. We conclude that low dose aspirin (80-100 mg daily) in addition to warfarin in patients with prosthetic heart valves reduces all cause long term mortality (NNT=19), with significant reductions in thromboembolism but an increase in bleeding.     

Use of flexibility tests in the manufacturing process of 60 degrees Björk-Shiley convexo-concave valves and the risk of outlet strut fracture

OBJECTIVES: Outlet strut fracture remains a concern for 30,000 patients living with a Bj?rk-Shiley convexo-concave heart valve (Shiley, Inc, Irvine, Calif, a subsidiary of Pfizer, Inc). Previous studies (Netherlands and United Kingdom) investigating valve manufacturing aspects identified multiple performance of the hook deflection test as a risk factor for 60 degrees valves. The present study validated this finding using new data with a greater number of valves implanted worldwide. Risks of outlet strut fracture associated with other manufacturing aspects were also investigated. METHODS: A matched case-control study design was used including 416 outlet strut fracture cases and 803 controls. RESULTS: Analyses similar to that of the Dutch and United Kingdom studies produced odds ratios of 3.4 (95% confidence interval [CI]: 1.1-10.3) and 2.8 (95% CI: 1.1-7.3), respectively, for multiple hook deflection tests. Load deflection test, which replaced the hook deflection test, showed a statistically significant association with outlet strut fracture: odds ratio of 5.0 (95% CI: 2.1-11.8) and 6.2 (95% CI: 2.2-18.0) for single and multiple load deflection tests, respectively. An analysis where hook deflection tests were separated from load deflection tests showed significantly elevated odds ratios with performance of any type of flexibility test, and the highest odds ratio was observed with a combined performance of load and hook deflection tests. CONCLUSIONS: Multiple hook deflection tests can now be considered for inclusion in the risk model used for guidelines on explant surgery to improve prediction of outlet strut fracture and provide patient reassurance. Load deflection tests and combined performance of hook and load deflection tests were found to be significant risk factors. No outlet strut fractures were reported for valves manufactured after March 1984 when the load deflection test was still in place. Examining manufacturing documents for these valves may identify new risk factors that could be responsible for the outlet strut fractures risk that remains unexplained to date.     

Survival in prostate cancer patients ≥70 years after radical prostatectomy and comparison to younger patients

Purpose  

The purpose of our study was to evaluate and compare the survival in prostate cancer (PCa) patients who underwent radical prostatectomy (RP) < and ≥70 years.     

Survival and long-term outcomes after mitral valve replacement in patients aged 18 to 50 years

Objective

To provide long-term data on survival and major morbidity after mitral valve replacement in patients aged 18 to 50 years.

Potential presence of metals in patients treated with metal–metal coupling prostheses for hip arthroplasty at 7 and 10 years of follow-up

Background

Beginning in 2008, metal-on-metal prostheses have been in the spotlight owing to much higher revision rates than expected. Adverse local tissue reactions have been well described in the literature as potential complications.

Methods

Between 2012 and 2013, 13 patients with metal-on-metal total hip replacements were evaluated clinically and radiologically and with laboratory samples. The same tests were repeated between 2015 and 2016 on eight patients to assess any changes. In the laboratory assessment, we searched for chromium, cobalt, molybdenum, and nickel in blood and urine samples over 24 h.

Results

Clinical assessment has shown good score in all patients except one. On a second examination, between 2015 and 2016, all patients obtained results similar to those obtained in the first assessment, except a patient, who reported a recent fall. In the radiological assessment between 2012 and 2013, results were optimal, apart from a case of aseptic mobilization. The patients reassessed 3 years after the first examination showed radiological results similar to those previously obtained, apart from a patient, who showed signals of mobilization. Metal levels found in their blood decreased in most cases after 3 years. Urine levels of nickel increased in five subjects, and chromium levels increased in four, but levels of cobalt and molybdenum decreased in four patients.

Conclusion

It could be hypothesized that the decreasing trend of metal ion levels is associated with a stable wear status. On the contrary, a progressive increase in metal ion levels must be considered as early proof of implant loosening.

     

Conversion to sirolimus of patients with chronic allograft nephropathy—a retrospective analysis of outcome and influencing factors

Purpose

The purpose of this study was to analyse the outcome and its influencing factors in patients whose therapy was converted from calcineurin inhibitors (CNI) to sirolimus (SRL) due to chronic allograft nephropathy (CAN).

Materials and methods

Therapies of 78 patients (44 men) with CAN from three European transplant centres were converted from CNI therapy to SRL and followed 24 months. Slopes for creatinine clearance before and after conversion were calculated. Influencing factors were analysed by a multivariance analysis.

Results

The slope of the creatinine clearance improved significantly (?0.90 vs. ?0.34 ml min^?1 month^?1; p?<?0.01). In patients whose therapy was converted from cyclosporine A (CyA) to SRL, the slope improved significantly, whereas conversion from Tacrolimus (Tac) to SRL did not affect the slope. The benefit was more pronounced in (1) patients with low or moderate baseline creatinine clearance, (2) patients receiving SRL after conversion without additional mycophenolate mofetil and (3) patients with low or moderate proteinuria.

Conclusion

Conversion from CyA to SRL but not from Tac to CRL is associated with a reduced loss of renal allograft function in patients with CAN.     

The lifetime risk of pneumonia in patients with neuromuscular scoliosis at a mean age of 21?years: the role of spinal deformity surgery

Background

Patients with neuromuscular disorders often have an increased risk of pneumonia and decreased lung function, which may further be compromised by scoliosis. Scoliosis surgery may improve pulmonary function in otherwise healthy patients, but no study has evaluated its effect on the risk of pneumonia in patients with neuromuscular scoliosis (NMS).

Methods

The patient charts of 42 patients (mean age 14.6 years) who had undergone surgery for severe NMS (mean scoliosis 86°) were retrospectively reviewed from birth to a mean of 6.1 years (range 2.8–9.5) after scoliosis surgery. The main outcome was radiographically confirmed pneumonia as a primary cause for hospitalization. We excluded postoperative (3 months) pneumonia from the analyses.

Results

The lifetime annual incidence of pneumonia was 8.0/100 before and 13.4/100 after scoliosis surgery (p > 0.10). The mean number of hospital days per year due to pneumonia were 0.59 (SD 2.3) before scoliosis surgery and 2.24 (SD 6.9) after surgery (p > 0.10). Multivariate analysis demonstrated that lifetime risk factors for pneumonia were epilepsy (RR 15.2, 95 % CI 1.3–176.8, p = 0.027), non-cerebral palsy (CP) etiology (RR = 10.2, 95 % CI 3.2–32.7, p < 0.001) and major scoliosis (main curve >70°; RR = 11.3, 95 % CI 1.8–70.7, p = 0.01).

Conclusions

Epilepsy, non-CP etiology and major scoliosis are significant risk factors for pneumonia in patients with NMS. Scoliosis surgery does not decrease the incidence of pneumonia in patients with severe NMS.

Level of Evidence

Retrospective comparative study, Level III.

Electronic supplementary material

The online version of this article (doi:10.1007/s11832-015-0682-8) contains supplementary material, which is available to authorized users.     

High-flexion TKA in patients with a minimum of 120 degrees of pre-operative knee flexion: outcomes at six?years of follow-up

We prospectively evaluated outcomes of high-flexion total knee arthroplasty in 165 patients who had advanced arthritis with a minimum 120-degree pre-operative knee flexion, with a mean follow-up of 77 months. Patients were divided into two groups according to their ability to perform full-range (heel-to-buttock) pre-operative knee flexion (group A) and the inability to do so (group B). The overall clinical rating was “excellent” in 96% of patients and “good” in 4% of patients. Mean maximum knee flexion decreased from 137.9° to 134.8°, with no statistical difference between pre- and post-operative knee flexion. However, patients in group A had significantly decreased knee flexion (146.2° vs. 135.0°, p < 0.001), whereas patients in group B exhibited no change in knee flexion (133.7° vs. 134.7°, p = 0.14). We found that 14.7%, 36.5% and 43.0% of the studied patients could engage in kneeling, Thai polite style sitting and cross-legged sitting, respectively, with no significant differences between groups A and B. The survival rates for any reoperation and prosthesis-related problem (such as early loosening) at six years were 98.3% and 100%, respectively. At six-year follow-up in patients with well preserved pre-operative knee flexion, the high-flexion knee prosthesis provided a favourable outcome without improving knee flexion.     

Is there a suitable method of anticoagulation in pregnant patients with mechanical prosthetic heart valves?

A best evidence topic was written according to a structured protocol in order to identify the mode of anticoagulation that has the best safety profile for both the mother and the foetus in pregnant patients with mechanical prosthetic heart valves. A total of 281 papers were identified using the reported search, of which eight represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. The reported measures were foetal mortality, maternal mortality, congenital abnormalities and embryopathy, and maternal thromboembolic and haemorrhagic complications. The medical orthodoxy has warned of the combination of oral anticoagulation and pregnancy due to the well-documented warfarin embryopathy. Yet only one of the reported papers identified a greater incidence of foetal aberrations among warfarin use, with the highest reported rate being 6.4% and two of the assessed papers reporting no embryopathy at all. Foetal mortality with oral anticoagulation use ranged from 1.52 to 76%. All reported publications demonstrated a superior maternal outcome with warfarin use, with a range of thromboembolic events from 0 to 10% in comparison with 4 to 48% where heparin was used. Thus, it is concluded that warfarin is a more durable anticoagulant with a better maternal outcome despite it carrying a greater foetal risk. Although, in contrast to previous teaching, the risks of embryopathy are not the major drawback of oral anticoagulation. Heparin is consistently less effective, but may be preferred for the superior foetal outcome. Heparin usage during the first trimester reduces the foetal risk but is still associated with an adverse maternal outcome. While the focus for clinicians looking after pregnant women with mechanical heart valves may be to prevent maternal thromboembolic complications, the overriding concern for many women is to avoid any harm to their unborn child, even when this places their health at risk. Thus women with mechanical heart valves must be fully informed of the risks involved with different anticoagulation for an informed decision to be made.     

Colorectal endoscopic submucosal dissection for elderly patients at least 80?years of age

Background

Endoscopic submucosal dissection (ESD) has been used recently for successful en bloc resection of even large lesions, although no consensus appears in medical literature concerning its application to elderly patients. This prospective cohort study aimed to evaluate the efficacy and safety of colorectal ESD for patients 80?years of age or older.

Methods

Colorectal ESD procedure findings were compared with clinical outcomes, including associated complications and mortalities, for two age groups totaling 196 consecutive patients with 202 colorectal lesions. Of the 196 patients, 31 patients (16%) were 80?years of age or older (group E), and 165 patients (84%) were younger than 80?years (group Y).

Results

The median ages were 82?years in group E and 68?years in group Y. The frequency of chronic concomitant diseases was significantly higher in group E (65%) than in group Y (27%) (p?=?0.003). No significant pressure decrease or need for oxygenation was observed in either group. In addition, groups E and Y did not differ significantly in terms of mean lesion sizes (40.9 vs. 39.7?mm) en bloc resection rates (84% vs. 93%), curative rates (78% vs. 84%), median procedure times (65 vs. 70?min), or associated complications (no perforation or delayed bleeding cases [0%] vs. 5 perforations [3%]) The median postprocedure hospitalization period was 3?days in both groups. Except for 10 cases requiring subsequent lymph node dissection surgery, follow-up colonoscopy examinations showed no recurrences or ESD-related mortalities in either group.

Conclusion

Colorectal ESD is a safe and effective treatment for elderly patients (age????80?years) despite a significantly higher frequency of chronic concomitant diseases than among younger patients.     

Clinical outcomes of patients 80 years of age and older with soft tissue sarcoma

Objectives

Although soft tissue sarcoma (STS) is rare, its incidence is increasing among older patients. Few studies have compared the outcomes between conservative and surgical treatments for STS patients aged ≥80 years. We assessed the outcomes of both treatments in this population and the association between older age and surgical outcome.

Which patients do not recover from shoulder impingement syndrome,either with operative treatment or with nonoperative treatment?: Subgroup analysis involving 140 patients at 2 and 5 years in a randomized study

Background and purpose — Shoulder impingement syndrome is common, but treatment is controversial. Arthroscopic acromioplasty is popular even though its efficacy is unknown. In this study, we analyzed stage-II shoulder impingement patients in subgroups to identify those who would benefit from the operation.Patients and methods — In a previous randomized study, 140 patients were either treated with a supervised exercise program or with arthroscopic acromioplasty followed by a similar exercise program. The patients were followed up at 2 and 5 years after randomization. Self-reported pain was used as the primary outcome measure.Results — Both treatment groups had less pain at 2 and 5 years, and this was similar in both groups. Duration of symptoms, marital status (single), long periods of sick leave, and lack of professional education appeared to increase the risk of persistent pain despite the treatment. Patients with impingement with radiological acromioclavicular (AC) joint degeneration also had more pain. The patients in the exercise group who later wanted operative treatment and had it did not get better after the operation.Interpretation — The natural course probably plays a substantial role in the outcome. Based on our findings, it is difficult to recommend arthroscopic acromioplasty for any specific subgroup. Regarding operative treatment, however, a concomitant AC joint resection might be recommended if there are signs of AC joint degeneration. Even more challenging for the development of a treatment algorithm is the finding that patients who do not recover after nonoperative treatment should not be operated either.Shoulder impingement syndrome has traditionally been divided into 3 progressive stages: (1) edema and hemorrhage (stage I), (2) fibrosis and tendinitis (stage II), and (3) tears of the rotator cuff, biceps ruptures, and bone changes (stage III) (Neer 1983). Nowadays, the term impingement syndrome is used to refer to a full range of rotator cuff abnormalities, being still a diagnosis based on physical examination (Papadonikolakis et al. 2011). Diercks et al. (2014) highlighted the need for a combination of clinical tests in the diagnosis, and suggested the use of an imaging test after prolonged symptoms (of more than 6 weeks) to rule out rotator cuff tears. Shoulder impingement is a common cause of shoulder pain (van der Windt et al. 1995, Urwin et al. 1998). Tendinopathy is considered to have a multifarious etiology: intrinsic mechanisms may be more important than extrinsic mechanisms (Factor and Dale 2014).Both nonoperative treatment and operative treatment have been used to treat this syndrome (Coghlan et al. 2008, Dorrestijn et al. 2009, Kromer et al. 2009, Chaudhury et al. 2010). It has been shown that arthroscopic acromioplasty is not superior to a supervised exercise program (Ketola et al. 2009, 2013, Papadonikolakis et al. 2011, Diercks et al. 2014, Saltychev et al. 2015). However, arthroscopic acromioplasty has been increasingly used during the last decade (Paloneva et al. 2015). Similar results have been obtained with open and arthroscopic acromioplasty (Davis et al. 2010). It is unclear whether a specific subgroup of patients who would benefit from arthroscopic acromioplasty can be identified. In most studies, the inclusion criterion has simply been failure of nonoperative treatment (Brox et al. 1999, Henkus et al. 2009). We have already done a cost-effectiveness study that suggested that arthroscopic acromioplasty followed by a structural exercise program is less cost-effective than exercise treatment alone (Ketola et al. 2009), and this was confirmed by Saltychev et al. (2015). We have now analyzed the 140 impingement patients from our previous study (Ketola et al. 2009) in subgroups to find out whether there is a subgroup of patients who would really benefit from arthroscopic acromioplasty. Secondly, we wanted to determine whether there is a subgroup in which the procedure should be avoided.     

Cementless Revision TKA with Bone Grafting of Osseous Defects Restores Bone Stock with a Low Revision Rate at 4 to 10 years

Background  

Addressing bone loss in revision TKA is challenging despite the array of options to reconstruct the deficient bone. Biologic reconstruction using morselized loosely-packed bone graft potentially allows for augmentation of residual bone stock while offering physiologic load transfer. However it is unclear whether the reconstructions are durable.     

What level of symptoms are patients with adult spinal deformity prepared to live with? A cross-sectional analysis of the 12-month follow-up data from 1043 patients

European Spine Journal - Previous studies suggest that a meaningful and easily understood measure of treatment outcome may be the proportion of patients who are in a “patient acceptable...     

Survivorship analysis of 150 consecutive patients with DIAM? implantation for surgery of lumbar spinal stenosis and disc herniation

Recently, the Device for Intervertebral Assisted Motion (DIAM™) has been introduced for surgery of degenerative lumbar disc diseases. The authors performed the current study to determine the survivorship of DIAM™ implantation for degenerative lumbar disc diseases and risk factors for reoperation. One hundred and fifty consecutive patients underwent laminectomy or discectomy with DIAM™ implantation for primary lumbar spinal stenosis or disc herniation. The characteristics of the 150 patients included the following: 84 males and 66 females; mean age at the time of surgery, 46.5 years; median value of follow-up, 23 months (range 1–48 months); 96 spinal stenosis and 54 disc herniations; and 146 one-level (115, L4–5; 31, L5–6) and 4 two-level (L4–5 and L5–6). In the current study, due to lumbosacral transitional vertebra (LSTV) L6 meant lumbarization of S1 and this had a prominent spinous process so that the DIAM™ was implanted at L5–6. Reoperations due to any reasons of the DIAM™ implantation level or adjacent levels were defined as a failure and used as the end point for determining survivorship. The cumulative reoperation rate and survival time were determined via Kaplan–Meier analysis. The log-rank test and Cox regression model were used to evaluate the effect of age, gender, diagnosis, location, and level of DIAM™ implantation on the reoperation rate. During a 4-year follow-up, seven patients (two males and five female) underwent reoperation at the DIAM™ implantation level, giving a reoperation rate of 4.7%. However, no patients underwent reoperation for adjacent level complications. The causes of reoperation were recurrent spinal stenosis (n = 3), recurrent disc herniation (n = 2), post-laminectomy spondylolisthesis (n = 1), and delayed deep wound infection (n = 1). The mean time between primary operation and reoperation was 13.4 months (range 2–29 months). Kaplan–Meier analysis predicted an 8% cumulative reoperation rate 4 years post-operatively. Survival time was predicted to be 45.6 ± 0.9 months (mean ± standard deviation). Based on the log-rank test, the reoperation rate was higher at L5–6 (p = 0.002) and two-level (p = 0.01) DIAM™ implantation compared with L4–5 and one-level DIAM™ implantation. However, gender (p = 0.16), age (p = 0.41), and diagnosis (p = 0.67) did not significantly affect the reoperation rate of DIAM™ implantation. Based on a Cox regression model, L5–6 [hazard ratio (HR), 10.3; 95% CI, 1.7–63.0; p = 0.01] and two-level (HR, 10.4; 95% CI, 1.2–90.2; p = 0.04) DIAM™ implantation were also significant variables associated with a higher reoperation rate. Survival time was significantly lower in L5–6 (47 vs. 22 months, p = 0.002) and two-level DIAM™ implantation (46 vs. 18 months, p = 0.01) compared with L4–5 and one-level DIAM™ implantation. The current results suggest that 8% of the patients who have a DIAM™ implantation for primary lumbar spinal stenosis or disc herniation are expected to undergo reoperation at the same level within 4 years after surgery. Based on the limited data set, DIAM™ implantation at L5–6 and two-level in patients with LSTV are significant risk factors for reoperation.