Impact of Hemodialysis on Surgical Outcomes and Mortality Rate after Lumbar Spine Surgery: A Matched Cohort Study

Outcomes of radiofrequency ablation for liver tumors in patients on hemodialysis: Results from the US Nationwide Inpatient Sample 2005-2020

OBJECTIVE

Few studies have examined the outcomes of radiofrequency ablation (RFA) for liver tumors in patients on hemodialysis. This study aimed to investigate short-term outcomes following RFA for liver tumors in patients on hemodialysis.

METHODS

Data of patients ≥ 20 years old diagnosed with liver tumors who underwent RFA were extracted from the Nationwide Inpatient Sample (NIS) database 2005-2020. The study population was divided into two groups: patients on hemodialysis and those not on hemodialysis. Propensity score matching (PSM) was employed to address baseline differences. Associations between hemodialysis and in-hospital outcomes, including prolonged length of stay (LOS), in-hospital mortality, unfavorable discharge, and complications were determined using logistic regression analyses.

RESULTS

After applying the inclusion and exclusion criteria, a total of 12,749 patients constituted the study population, with 550 remaining after 1:4 PSM (110 on hemodialysis and 440 without hemodialysis). After adjustment in the multivariable analyses, patients on maintenance hemodialysis showed significantly higher risks of prolonged LOS (adjusted odds ratio [aOR] = 2.88, 95 % confidence interval [CI]: 1.78-4.65), in-hospital mortality (aOR=31.90, 95 % CI: 17.68-57.58), unfavorable discharge (aOR=3.79, 95 % CI: 2.05-7.01), at least one complications (aOR=3.68, 95 % CI: 2.49-5.44), and greater total hospital costs (adjusted Beta [aBeta] = 126.75, 95 % CI: 113.68-139.82).

CONCLUSIONS

Patients on hemodialysis undergoing RFA for liver tumors have greater risks of adverse short-term outcomes including in-hospital mortality, prolonged LOS, complications, and unfavorable discharge. Careful consideration and close monitoring are warranted for patients on hemodialysis when planning for RFA.3.

Long-term outcomes of spine surgery in dialysis patients, focusing on activities of daily living, life expectancy, and the risk factors for postoperative mortality

BACKGROUND

Because of the high incidence of major perioperative adverse events, spine surgery in dialysis patients should be recommended carefully after consideration of its risks and benefits. However, the benefits of spine surgery in dialysis patients remain unclear because of the lack of long-term outcomes. The purpose of this study is to elucidate the long-term outcomes of spine surgery in dialysis patients, focusing on activities of daily living (ADLs), life expectancy, and risk factors for postoperative mortality.

METHODS

Data for 65 dialysis patients who underwent spine surgery at our institution and were followed up for a mean duration of 6.2 years were retrospectively reviewed. ADLs, number of surgeries, and survival times were recorded. The postoperative survival rate was calculated using the Kaplan-Meier method, and risk factors for postoperative mortality were investigated using a generalized Wilcoxon test and multivariate Cox proportional-hazards model.

RESULTS

Compared with preoperative ADLs, ADLs significantly improved at discharge after surgery and at the final follow-up. However, 16 of the 65 patients (24.6%) underwent multiple surgeries, and 34 (52.3%) died during the follow-up period. Kaplan-Meier analysis revealed that the survival rate after spine surgery was 95.4% at 1 year, 86.2% at 3 years, 69.6% at 5 years, 59.7% at 7 years, and 28.7% at 10 years, and the overall median survival time was 99 months. Multivariate Cox regression analysis showed that a dialysis period of ≥10 years was a significant risk factor.

CONCLUSIONS

Spine surgery in dialysis patients improved and maintained ADLs in the long term and did not shorten life expectancy. However, dialysis patients undergoing spine surgery require multiple surgeries more frequently, and a dialysis period of ≥10 years is a significant risk factor for postoperative mortality.

Clinical Outcomes of Lateral Lumbar Interbody Fusion with Percutaneous Pedicle Screw for Dialysis-Related Spondyloarthropathy

Background: The usefulness and problems with lateral lumbar interbody fusion (LLIF) with a percutaneous pedicle screw (PPS) for dialysis-related spondyloarthropathy are not clear. Therefore, we investigated the usefulness and problems with LLIF with PPS in dialysis-related spondyloarthropathy. Methods: In total, 77 patients who underwent LLIF with PPS were divided into two groups: the dialysis-related spondyloarthropathy group ("Group D") consisted of 15 patients (10 males and 5 females) with a mean age of 70.4 years and a mean duration of hemodialysis of 10.8 years; and the lumbar degenerative disease group ("Group L") included 62 patients (31 males and 31 females) with a mean age of 71.0 years. The mean follow-up period was 4 years in Group D and 3 years 9 months in Group L. We compared surgical invasiveness (operative time, blood loss), perioperative complications, clinical outcomes (Improvement ratio of the JOA score), bone fusion rate, reoperation, sagittal alignment, and coronal imbalance between the two groups. Results: There were no significant differences in operative time, blood loss, or the improvement ratio of the JOA score, but dialysis-related spondyloarthropathy was observed in one patient with superficial infection, three patients with endplate failure, and one patient with restenosis due to cage subsidence. Conclusions: We consider LLIF with PPS for dialysis-related spondyloarthropathy to be an effective treatment option because its surgical invasiveness and clinical outcomes were comparable to those for cases of lumbar degenerative disease. However, as endplate failure due to bone fragility and a reduced bone fusion rate were observed in dialysis spondylolisthesis cases, we advise a careful selection of indications for indirect decompression as well as the application of suitable pre- and postoperative adjuvant therapies.

Minimally invasive LLIF surgery to decrease the occurrence of adjacent-segment disease compared to conventional open TLIF

PURPOSE

Lateral lumbar interbody fusion with percutaneous pedicle screw fixation (Mis-LLIF) can establish indirect decompression by lifting the vertebra with a large intervertebral cage, which causes less damage to the posterior elements. Thus, Mis-LLIF is expected to reduce the incidence of adjacent segment disease (ASD). The aim of the study was to compare the occurrence of ASD between Mis-LLIF and conventional open transforaminal interbody fusion (TLIF).

METHODS

A total of 156 patients (TLIF group = 88, Mis-LLIF group = 68) who underwent single-level lumbar interbody fusion (L2/3, L3/4, or L4/5) at a single institution between 2003 and 2018 with minimum 2-year follow-up were retrospectively reviewed. The incidence of symptomatic ASD requiring reoperation (S-ASD) and radiological adjacent segment degeneration (R-ASD) 2 years postoperatively were investigated between 51 paired patients from both groups who were propensity score (PS) matched by demographic and baseline clinical data. The effect of characteristics arising from differences in surgical methods between Mis-LLIF and TLIF, such as the amount of distraction of the index fused level (∆H), on S-ASD and R-ASD was also examined.

RESULTS

There were no significant differences in the incidence of S-ASD between the Mis-LLIF and TLIF groups (adjusted OR 1.3; 95% CI 0.41-3.9). There was no significant difference in the incidence of R-ASD between the Mis-LLIF and TLIF groups both at the cranial (adjusted OR 1.0; 95% CI 0.22-4.5) and caudal level (adjusted OR 1.5; 95% CI 0.44-5.3). On the other hand, ∆H was significantly higher in the Mis-LLIF group than in the TLIF group (3.6 mm vs. 1.7 mm, respectively, P < 0.0001), and was extracted as a significant independent risk factor for S-ASD (adjusted HR 2.7; 95% CI 1.1-6.3) and R-ASD at the cranial side (adjusted HR 6.4; 95% CI 1.7-24) in multivariable analysis with PS adjustment.

CONCLUSIONS

The incidence of R-ASD or S-ASD was not significantly reduced in the Mis-LLIF group compared to the TLIF group, with greater ∆H potentially being a contributing factor. Using a thin cage in both TLIF and Mis-LLIF may decrease the occurrence of ASD.

The impact of stratified hypoalbuminemia and dialysis on morbidity/mortality after posterior spinal fusion surgery: An ACS-NSQIP study

Background:

Preoperative optimization in patients undergoing posterior spinal fusion is essential to limit the number and severity of postoperative complications. Here, we, additionally, evaluated the impact of hypoalbuminemia on morbidity and mortality after posterior spinal fusion surgery.

Methods:

This retrospective analysis was performed using data from a prospective multicentric database (ACSNSQIP:2015–2020) regarding patients undergoing posterior spinal fusions. Factors studied included; baseline demographics and 30-day postoperative complications (i.e., reoperations, readmissions, and mortality rates).

Results:

There were 6805 patients who met the inclusion criteria. They averaged 62 years of age and had an average BMI of 30.2. Within the 30-day postoperative period, 634 (9.3%) sustained complications; 467 (6.9%) were readmitted, 263 (3.9%) required reoperations, and 37 (0.5%) expired. Although multiple preoperative risk factors were analyzed, hypoalbuminemia, severe hypoalbuminemia, and dialysis were the strongest independent risk factors associated with complications (i.e., reoperations, readmissions, and mortality).

Conclusion:

Hypoalbuminemia, severe hypoalbuminemia, and dialysis were significant predictors for morbidity and mortality after posterior spinal fusion surgery.

Preoperative hypoalbuminemia and dialysis increase morbidity/mortality after spine surgery for primary pyogenic spinal infections (ACS-NSQIP Study)

Background:

We analyzed the role of hypoalbuminemia, dialysis, and other risk factors that increase morbidity/ mortality following surgery for primary pyogenic spinal infections (PSIs). The American College of Surgeons’ National Surgical Quality Improvement Program (ACS-NSQIP) that included 627 patients was utilized as our database.

Methods:

Primary spinal surgery for spondylodiscitis was evaluated in a ACS-NSQIP database involving 627 patients between 2010 and 2019. Outcome assessment included evaluation of 30-day postoperative morbidity, and mortality rates.

Results:

Within 30 postoperative days, complications occurred in 14.6% (92/627) of patients; 59 (9.4%) required readmission, and 39 (6.2%) required additional surgery. The most common complications were: wound infections, pneumonia, septic shock, and death (1.8%). Hypoalbuminemia (i.e., significantly associated with unplanned readmission and reoperation), and dialysis were the two major risk factors contributing to increased perioperative morbidity and mortality.

Conclusion:

Among 627 ACS-NSQIP patients undergoing primary surgery for PSIs, hypoalbuminemia and dialysis were associated with higher risks of major perioperative morbidity (i.e., within 30 postoperative days – mostly readmissions and reoperations) and mortality.

Dynamization-Posterior Lumbar Interbody Fusion for Hemodialysis-Related Spondyloarthropathy: Evaluation of the Radiographic Outcomes and Reoperation Rate within 2 Years Postoperatively

Study Design

Clinical case series.

Purpose

This study aimed to report dynamization-posterior lumbar interbody fusion (PLIF), our surgical treatment for hemodialysisrelated spondyloarthropathy (HSA), and investigate patients' postoperative course within 2 years.

Overview of Literature

HSA often requires lumbar fusion surgery. Conventional PLIF for HSA may cause progressive destructive changes in the vertebral endplate, leading to progressive cage subsidence, pedicle screw loosening, and pseudoarthrosis. A dynamic stabilization system might be effective in patients with a poor bone quality. Thus, we performed "dynamization-PLIF" in hemodialysis patients with destructive vertebral endplate changes.

Methods

We retrospectively examined patients with HSA who underwent dynamization-PLIF at our hospital between April 2010 and March 2018. The radiographic measurements included lumbar lordosis and local lordosis in the fused segment. The evaluation points were before surgery, immediately after surgery, 1 year after surgery, and 2 years after surgery. The preoperative and postoperative radiographic findings were compared using a paired t-test. A p-value of less than 0.05 was considered significant.

Results

We included 50 patients (28 males, 22 females). Lumbar lordosis and local lordosis were significantly improved through dynamization- PLIF (lumbar lordosis, 28.4°-35.5°; local lordosis, 2.7°-12.8°; p<0.01). The mean local lordosis was maintained throughout the postoperative course at 1- and 2-year follow-up (12.9°-12.8°, p=0.89 and 12.9°-11.8°, p=0.07, respectively). Solid fusion was achieved in 59 (89%) of 66 fused segments. Solid fusion of all fixed segments was achieved in 42 cases (84%). Within 2 years postoperatively, only six cases (12%) were reoperated (two, surgical debridement for surgical site infection; two, reoperation for pedicle screw loosening; one, laminectomy for epidural hematoma; one, additional fusion for adjacent segment disease).

Conclusions

Dynamization-PLIF showed local lordosis improvement, a high solid fusion rate, and a low reoperation rate within 2 years of follow-up.

Possible Association of Pedicle Screw Diameter on Pseudoarthrosis Rate After Transforaminal Lumbar Interbody Fusion

BACKGROUND

Although pedicle screw sizes may affect the rate of bone union after lumbar fusion surgery, there is currently no supportive clinical evidence.

METHODS

Eighty-five patients older than 50 years who underwent single-level L4/5 transforaminal lumbar interbody fusion with posterior pedicle screw (PS) fixation were analyzed. Patients with factors that potentially inhibit bone fusion, such as Parkinson disease, were excluded. Bone union was assessed using computed tomography and dynamic radiographs 1 year after surgery. Explanatory factors considered included sex, age, smoking, bone density, material of the cage, PS diameter (PSD), relative PS length, theoretical maximum PSD (PSD_max), which was defined as the maximum diameter of the screw that may be inserted without breaking cortical bone around the pedicle, and the filling index, which was defined as the difference between the cross-sectional area of maximum PS and actual PS (PSD_max^ˆ 2 - PSD ^ˆ 2). Japanese Orthopaedic Association scores before and 1 year after surgery were evaluated as a clinical outcome.

RESULTS

Nineteen levels were diagnosed as pseudoarthrosis. A multivariate logistic regression analysis identified a larger filling index (P = 0.016) and older age (P = 0.047) as risk factors for pseudoarthrosis. The Japanese Orthopaedic Association score 1 year after surgery and its recovery rate were significantly worse in patients with pseudoarthrosis than in those with fusion.

CONCLUSIONS

The selection of an appropriately sized screw is important for achieving rigid fusion after transforaminal lumbar interbody fusion. Preoperative planning using multiplanar reconstruction computed tomography is an important approach for ensuring good clinical results.