Clinical Outcomes of Spinal Surgery for Patients Undergoing Hemodialysis

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.

Perioperative Nutritional Supplementation Decreases Wound Healing Complications Following Elective Lumbar Spine Surgery: A Randomized Controlled Trial

BACKGROUND

The prevalence of malnutrition in patients undergoing lumbar spine surgery ranges from 5% to 50% and is associated with higher rates of surgical site infections, medical complications, longer lengths of stay, and mortality.

PURPOSE

To determine if perioperative nutritional intervention decreases wound healing complications in patients undergoing lumbar spine surgery.

STUDY DESIGN/SETTING

A prospective randomized controlled trial.

MATERIALS AND METHODS

Patients aged 55+ undergoing elective primary lumbar surgery were included. Patients with a preoperative albumin<3.5 g/dL were defined as malnourished. Intervention group received nutritional supplementation (protein shake) twice daily from postoperative day 0 to two weeks postdischarge. Control group was instructed to continue regular daily diets. Primary outcomes included minor in-hospital complications (wound drainage, electrolyte abnormalities, hypotension, ileus, deep venous thrombus) and wound healing complications within 90 days. Secondary outcomes included 90-day emergency room visits, readmissions, and return to the operating room. Baseline data were compared between groups using means comparison tests. Multivariable analysis evaluated association of outcomes with nutritional supplementation. Subanalysis of malnourished patients assessed effects of nutritional supplementation on outcomes.

RESULTS

One hundred three patients were included. Thirty-seven (35.9%) were considered malnourished preoperatively. Forty-six (44.7%) received nutritional intervention and 57 (55.3%) served as controls. Adjusted analysis found patients receiving supplementation had lower rates of in-hospital minor complications (2.1% vs. 23.2%, P <0.01), and perioperative wound healing complications (3.4% vs. 17.9%, P <0.05). Subgroup analysis of 37 malnourished patients demonstrated that malnourished patients who received perioperative nutritional supplementation had lower rates of minor complications during admission (0.0% vs. 34.4%, P =0.01) and return to the operating room within 90 days (0.0% vs. 12.4%, P =0.04).

CONCLUSIONS

Over one third of patients undergoing lumbar surgery were malnourished. Nutritional supplementation during the two-week perioperative period decreased rates of minor complications during admission and wound complications within 90 days. Malnourished patients receiving supplementation less often returned to the operating room. To our knowledge, this is the first study to investigate the effects of perioperative nutritional intervention on wound healing complications for patients undergoing elective lumbar spine surgery.

LEVEL OF EVIDENCE

I.

Postoperative Complications and Survival Rate in Hemodialysis-Dependent Patients Undergoing Cervical Spine Surgery

Introduction

Spine surgery is challenging in hemodialysis (HD)-dependent patients owing to their poor general condition. However, postoperative complications and the mortality and survival rates have not been specifically evaluated in a wide series. This study aimed to elucidate postoperative complications and the survival rate in cervical spine surgery in HD patients.

Methods

This study included 109 HD patients (70 men, 39 women) who had undergone cervical spine surgery between July 1996 and May 2018. Based on radiological diagnosis, we divided them into the destructive spondyloarthropathy (DSA) and non-DSA groups. We investigated the causes of hemodialysis, postoperative complications, postoperative inpatient mortality rate, and survival rate.

Results

The DSA and non-DSA groups included 100 surgeries in 89 patients and 21 surgeries in 20 patients, respectively. The mean age at surgery was 62.9 years for the DSA and 55.9 years for the non-DSA group (P=0.97). The DSA group had a shorter hemodialysis period at surgery compared with the non-DSA group (21.7 vs. 26.5 years, P<0.05). The two most common causes of HD in both groups were chronic glomerulonephritis (DSA, 45%; non-DSA, 57.1%) and diabetes (DSA, 11%; non-DSA, 14.5%). Postoperative complications were observed in 23% (23/100) and 19% (4/21) of surgeries in the DSA and non-DSA groups, respectively (P=0.782). The total in-hospital mortality rate was 2.5% (3/121). The 1-, 3-, 5-, and 10-year postoperative survival rates of all patients were 89.6%, 75.5%, 67.1%, and 44.7%, respectively. The survival rates did not depend on the group (DSA vs. non-DSA), pre- and postoperative Japanese Orthopedic Association score for cervical myelopathy, hemodialysis period, sex, and age (P>0.05). However, significantly low survival rates were observed in HD caused by diabetes compared with that by chronic glomerulonephritis (P<0.001) and other causes (P<0.001).

Conclusions

Cervical spine surgery in HD patients is associated with postoperative complications. The postoperative survival rate was found to be low if the cause of hemodialysis was diabetes.

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.

Inpatient Outcomes in Dialysis Dependent Patients Undergoing Elective Cervical Spine Surgery for Degenerative Cervical Conditions

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate inpatient outcomes in dialysis dependent patients undergoing elective cervical spine surgery.

METHODS

A total of 1605 dialysis dependent patients undergoing elective primary or revision cervical spine surgery for degenerative conditions were identified from the National Inpatient sample from 2002 to 2012 and compared to 1 450 642 nondialysis-dependent patients undergoing the same procedures. The National Inpatient Sample is a de-identified database; thus, no institutional review board approval was needed.

RESULTS

Dialysis dependence was associated with higher inpatient mortality rates (7.5% vs 1.9%; P < .001) as well as both major (17.3% vs 0.6%; P < .001) and minor (36.8% vs 10.5%; P < .001) complication rates as compared with nondialysis-dependent patients. Dialysis-dependent patients had substantially increased mean lengths of stay (9.8 days compared with 2.0 days; P < .001) and total hospital charges ($141 790 compared with $46 562; P < .001).

CONCLUSION

Dialysis-dependence is associated with drastically increased complication rates, risk of mortality, and represent a significant financial and psychosocial burden to patients undergoing elective cervical spine surgery. Both surgeons and patients should be aware of these risks while planning elective surgeries.

Dialysis is an independent risk factor for perioperative adverse events, readmission, reoperation, and mortality for patients undergoing elective spine surgery

BACKGROUND CONTEXT

The prevalence of dialysis-dependent patients in the United States is growing. Prior studies evaluating the risk of perioperative adverse events for dialysis-dependent patients are either institutional cohort studies limited by patient numbers or administrative database studies limited to inpatient data.

PURPOSE

The present study uses a large, national sample with 30-day follow-up to investigate dialysis as risk factor for perioperative complications independent of patient demographics or comorbidities.

STUDY DESIGN/SETTING

This is a retrospective cohort study.

PATIENT SAMPLE

Patients undergoing elective spine surgery with or without dialysis from the 2005-2015 National Surgical Quality Improvement Program (NSQIP) database were included in the study.

OUTCOME MEASURES

Postoperative complications within 30 days and binomial reoperation, readmission, and mortality within 30 days were determined.

METHODS

The 2005-2015 NSQIP databases were queried for adult dialysis-dependent and dialysis-independent patients undergoing elective spinal surgery. Differences in 30-day outcomes were compared using risk-adjusted multivariate regression and coarsened exact matching analysis for adverse events, unplanned readmission, reoperation, and mortality. The percentage of complications occurring before versus after hospital discharge was also assessed. The authors have no financial disclosures related to the present study.

RESULTS

A total of 467 dialysis and 173,311 non-dialysis patients met the inclusion criteria. Controlling for age, gender, body mass index, functional status, and American Society of Anesthesiologists (ASA) class, dialysis patients were found to be at significantly greater odds of any adverse event (odds ratio [OR]=2.52 before, 2.17 after matching, p=<.001), major adverse event (OR=2.90 before, 2.52 after matching, p=<.001), and minor adverse event (OR=1.50 before matching, p=<.025, but not significantly different after matching). Further, dialysis patients were significantly more likely to return to the operating room (OR=2.77 before, 2.50 after matching, p=<.001), have unplanned readmissions (OR=2.73 before, 2.37 after matching, p=<.001), and die within 30 days (OR=3.77 before, 2.71 after matching, p=<.001). Adverse events occurred after discharge for 51.78% of non-dialysis patients and for 43.80% of dialysis patients.

CONCLUSIONS

Dialysis patients undergoing elective spine surgery are at significantly higher risk of aggregated adverse outcomes, return to the operating room, readmission, and death than non-dialysis patients, even after controlling for patient demographics and overall health (as indicated by ASA class). These differences need to be considered when determining treatment options. Additionally, with bundled payments expected in spine surgery, physicians and hospitals need to account for increased costs and liabilities when working with dialysis patients.

In-Hospital Outcomes of Patients With Advanced Chronic Kidney Disease, Dialysis, and Kidney Transplant Undergoing Spinal Fusion: Analysis of a Nationwide Database

STUDY DESIGN

A retrospective analysis of population-based national hospital discharge data collected for the nationwide inpatient sample (NIS).

OBJECTIVES

To examine the in-hospital outcomes of patients with advanced chronic kidney disease (CKD), dialysis, and kidney transplant undergoing spinal fusion on a national level.

SUMMARY OF BACKGROUND DATA

Patients with advanced CKD have been living longer with the support and improvement of medical treatment, dialysis, and organ transplant. Some of those patients undergo spinal fusion surgery. However, there is limited information regarding the outcomes of patients with advanced CKD, dialysis, and kidney transplant, undergoing spinal fusion.

METHODS

Clinical data were derived from the US Nationwide Inpatient Sample (NIS) between 2000 and 2009. Patients who underwent spinal fusion were identified and divided into 4 groups: those with advanced CKD, dialysis, and kidney transplant, and those without advanced CKD. Data regarding, patient-system and health care system-related characteristics, comorbidities, in-hospital complications, and mortality were retrieved and analyzed. In-hospital outcomes were compared between the groups and analyzed with the use of multivariate logistic regression.

RESULTS

Among the all groups, overall in-hospital complications rate was the highest (42.0%) for patients with advanced CKD and in-hospital mortality rate was the highest (5.2%) for those with dialysis, undergoing spinal fusion. Patients with dialysis had 8.7 and 9.5 times higher risk of in-hospital mortality compared with those with kidney transplant and those without advanced CKD.

CONCLUSIONS

Patients with advanced CKD, dialysis, and kidney transplant had significant higher rates and risks of in-hospital morbidity or mortality than those without advanced CKD, undergoing spinal fusion. Particularly, patients with dialysis undergoing spinal fusion need to be informed with high mortality risk.

In-Hospital Mortality After Spinal Surgery in Hemodialysis Patients: An 11-Year Population-Based Study

BACKGROUND

Patients with end-stage renal disease (ESRD) are at an increased risk of surgical mortality. We aimed to investigate the factors associated with in-hospital mortality in patients with ESRD who underwent spinal surgery, which remains to be determined.

MATERIAL AND METHODS

An age- and sex-matched cohort study was conducted using the Taiwan Longitudinal Health Insurance Database between January 2000 and December 2012. Kaplan-Meier curves were plotted with log-rank test to compare the differences between these 2 groups. The Cox proportional hazard model was used to estimate the hazard ratio of in-hospital mortality adjusted with potential confounding.

RESULTS

In total, 4109 participants with pre-existing ESRD and 8218 patients without ESRD were included. The in-hospital mortality in ESRD (10.17%) was greater than without ESRD (1.39%). Spinal surgery patients with pre-existing ESRD had a 6.78-fold increase in-hospital mortality risk compared with those without ESRD. Spinal surgery patients with ESRD of any age, male or female, and comorbidities experienced a greater incidence of hospital mortality. In patients with ESRD, operations on spinal cords and spinal canal structures had the greatest hospital mortality (14.87%) compared with spinal fusion (3.46%) or excision or destruction of intervertebral disc (3.01%). Kaplan-Meier survival curves showed that patients with ESRD experienced greater hospital mortality than patients without ESRD in all 3 spinal surgery methods (log rank P < 0.0001).

CONCLUSIONS

Spinal surgery patients with ESRD have greater in-hospital mortality than patients without ESRD. Age, sex, history of comorbidities, and types of surgical methods were associated with greater in-hospital mortality among patients with ESRD.

Postoperative Complications in Dialysis-Dependent Patients Undergoing Elective Decompression Surgery Without Fusion or Instrumentation for Degenerative Cervical or Lumbar Lesions

STUDY DESIGN

This was a single-institute retrospective study.

OBJECTIVE

To evaluate postoperative complications in dialysis-dependent patients undergoing elective cervical and lumbar decompression surgery.

SUMMARY OF BACKGROUND DATA

Spinal surgery in dialysis-dependent patients is very challenging due to the high risk of serious postoperative complications and mortality associated with their fragile general condition. However, the outcome of decompression surgery alone has not been evaluated in such patients.

METHODS

An electronic medical record review showed that 338 and 615 patients had undergone cervical and lumbar spine posterior decompression, respectively. Among them, 48 and 42, respectively were dialysis-dependent patients. Postoperative complications were compared between dialysis-dependent and non-dialysis-dependent patients.

RESULTS

Among patients who underwent cervical decompression, the rate of perioperative blood transfusion in dialysis-dependent patients (14.6%) was significantly higher than that in non-dialysis-dependent patients (0.7%). No severe complications or mortality occurred in association with cervical decompression. The incidence of postoperative complications in dialysis-dependent patients (6.3%) was not significantly different from that in non-dialysis-dependent patients (4.1%). Among patients who underwent lumbar decompression, the rate of perioperative transfusion in dialysis-dependent patients (11.9%) was also significantly higher than that in non-dialysis-dependent patients (0.7%). With respect to severe complications among patients who underwent lumbar decompression, cerebral hemorrhage occurred in one dialysis-dependent patient, and no mortality occurred. The incidence of postoperative complications in dialysis-dependent patients (9.2%) was not significantly different from that in non-dialysis-dependent patients (6.8%).

CONCLUSION

Among patients who underwent posterior decompression alone for cervical or lumbar lesions, the rate of perioperative blood transfusion was significantly higher in dialysis-dependent than in non-dialysis-dependent patients. However, the postoperative rates of severe complications and mortality were not significantly different between the two groups. Therefore, decompression surgery alone is considered a rational surgical method with less invasiveness for dialysis-dependent patients with a fragile general condition.

LEVEL OF EVIDENCE

3.

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

Introduction

Despite ongoing improvements in both dialysis and surgical techniques, spinal surgery in patients undergoing hemodialysis (HD) is a challenge to surgeons because of the high mortality rate. However, no previous studies have examined clinical outcomes after lumbar surgery in HD patients. The purpose of this study is to compare clinical outcomes and complication rates after lumbar spinal surgery in patients with or without hemodialysis.

Methods

This retrospective, matched cohort study was conducted to compare surgical outcomes between HD vs non-HD patients who underwent lumbar surgery at our hospital. Controls were individually matched to cases at a ratio of 1:2. Clinical outcomes, complications, and mortality rates were compared between the two groups.

Results

Twenty-nine patients in the HD group and 57 in the non-HD group were included in the current study. Five patients in the HD group died during the follow-up period, whereas no patients died in the non-HD group (mortality rate, 17.2% vs. 0%, P = 0.003). Japanese Orthopaedic Association (JOA) scores were significantly less improved in the HD group than in the non-HD group (11.9 vs. 14.2 preoperatively, P = 0.001; 19.9 vs. 25.1 at final follow-up, P < 0.001). Five patients underwent repeat surgery in the HD group, which was significantly higher than the non-HD group (17.2% vs. 3.5%, P = 0.041).

Conclusions

The current study indicates that patients undergoing HD had poor outcomes after lumbar spinal surgery. Moreover, 5 of 29 patients died within a mean 2.4-years follow-up. The indications for lumbar spine surgery in HD patients must be carefully considered because of poor surgical outcomes and high mortality rate.

Radiological Examination of Postoperative Cervical Alignment and Stability in Patients with Dialysis-Associated Spondylosis Excluding Destructive Spondyloarthropathy: Comparison with Patients with Cervical Spondylotic Myelopathy

Introduction

Several reports have demonstrated the surgical treatment strategy for patients with dialysis-associated spondylosis in the cervical spine (CDAS) with destructive spondyloarthropathy (DSA). However, studies focusing on the clinical outcome of patients with CDAS without DSA remain scarce. We aimed to review the treatment strategy of patients with CDAS but without DSA.

Methods

The clinical data and surgical records of consecutive patients with CDAS without DSA (n = 9; D-group) and cervical spondylotic myelopathy (CSM) (n = 30; C-group) who underwent modified double-door laminoplasty(DDL) were reviewed retrospectively. We investigated four radiologic factors in the pre-and postoperative periods that have been reported to be the risk factors for worsening of clinical symptoms in various studies and examined statistical comparison between the D and C groups.

Results

In the D group, the pre- versus postoperative C2-C7 sagittal angles were not significantly different, and only two patients (22%) had kyphosis postoperatively. There was a significant difference in the pre- and postoperative C2-C7 angles in the two groups (P = 0.031).

Regarding the change in segmental alignment, the local open angle increased at the C4/C5 level in the D group. Also there was a significant difference in the local angles between the two groups at C4/5 and C5/6 (P = 0.00038, and 0.037), suggesting that postoperative segmental mobility at C4/5 and C5/6 was higher in the D group than in the C group.

Conclusions

In the present study, DDL in patients with CDAS without DSA did not adversely affect the postoperative alignment and stability compared with CSM patients with CSM. However, patients in the D group may have a chance to develop DSA change at the C4/5 level in the future, and careful long-term follow-up is warranted.