Asymptomatic Construct Failure after Metastatic Spine Tumor Surgery: A New Entity or a Continuum with Symptomatic Failure?

Kumar Naresh,Patel Ravish,Tan Barry Wei Loong,Tan Jiong Hao,Pandita Naveen,Sonawane Dhiraj,Lopez Keith Gerard,Wai Khin Lay,Hey Hwee Weng Dennis,Kumar Aravind,Liu Gabriel Ka-Po 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.5

Study Design: Retrospective cohort study. Purpose: To study the incidence, onset, underlying mechanism, clinical course, and factors leading to asymptomatic construct failure (AsCF) after metastatic spinal tumor surgery (MSTS). Overview of Literature: The reported incidence rates for implant and/or construct failure after MSTS are low (1.9%–16%) and based on clinical presentations and revisions required for symptomatic failures (SFs). AsCF after MSTS has not been reported. Methods: We conducted a retrospective analysis of 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological AsCF were defined as presentation before and after 3 months, respec­tively. We analyzed patients with AsCF for risk factors and survival duration by performing competing risk regression analyses where AsCF was the event of interest, with SF and death as competing events. Results: We observed AsCF in 41/246 patients (16.7%). The mean time to onset of AsCF after MSTS was 2 months (range, 1–9 months). Median survival of patients with AsCF was 20 and 41 months for early and late failures, respectively. Early AsCF accounted for 80.5% of cases, while late AsCF accounted for 19.5%. The commonest radiologically detectable AsCF mecha­nism was angular deformity (increase in kyphus) in 29 patients. Increasing age (p<0.02) and primary breast (13/41, 31.7%) (p<0.01) tumors were associated with higher AsCF rates. There was a non-significant trend towards AsCF in patients with a spinal instability neoplastic score ≥7, instrumentation across junctional regions, and construct lengths of 6–9 levels. None of the patients with AsCF underwent revision surgery. Conclusions: AsCF after MSTS is a distinct entity. Most patients with early AsCF did not require intervention. Patients who survived and maintained ambulation for longer periods had late failure. Increasing age and tumors with a bet­ter prognosis have a higher likelihood of developing AsCF. AsCF is not necessarily an indication for aggressive/urgent intervention.

Symptomatic Construct Failure after Metastatic Spine Tumor Surgery

Kumar Naresh,Patel Ravish,Tan Jiong Hao,Song Joshua,Pandita Naveen,Hey Dennis Hwee Weng,Lau Leok Lim,Liu Gabriel Ka-Po,Thambiah Joseph,Wong Hee-Kit 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.4

Study Design: Retrospective cohort study.Purpose: To evaluate the incidence and presentation of symptomatic failures (SFs) after metastatic spine tumor surgery (MSTS). To identify the associated risk factors. To categorize SFs based on the management in these patients.Overview of Literature: Few studies have reported on the incidence (1.9%–16%) and risk factors of SF after MSTS. It is unclear whether all SFs, occurring in MSTS-patients, result in revision surgery.Methods: We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event.Results: We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21–87 years); 48.4% were women. The median time to failure was 5 months (range, 1–60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63–30.07; p<0.0009).Conclusions: The incidence of SF (5.7%) was low in patients undergoing MSTS although these patients did not undergo spinal fusion. Preoperative ambulators involved a 7 times higher risk of failure than non-ambulators. Preoperative SINS >7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.

Does Minimally Invasive Spine Surgery Minimize Surgical Site Infections?

Arvind Gopalrao Kulkarni,Ravish Shammi Patel,Shumayou Dutta 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.6

Study Design: Retrospective review of prospectively collected data. Purpose: To evaluate the incidence of surgical site infections (SSIs) in minimally invasive spine surgery (MISS) in a cohort of patients and compare with available historical data on SSI in open spinal surgery cohorts, and to evaluate additional direct costs incurred due to SSI. Overview of Literature: SSI can lead to prolonged antibiotic therapy, extended hospitalization, repeated operations, and implant removal. Small incisions and minimal dissection intrinsic to MISS may minimize the risk of postoperative infections. However, there is a dearth of literature on infections after MISS and their additional direct financial implications. Methods: All patients from January 2007 to January 2015 undergoing posterior spinal surgery with tubular retractor system and microscope in our institution were included. The procedures performed included tubular discectomies, tubular decompressions for spinal stenosis and minimal invasive transforaminal lumbar interbody fusion (TLIF). The incidence of postoperative SSI was calculated and compared to the range of cited SSI rates from published studies. Direct costs were calculated from medical billing for index cases and for patients with SSI. Results: A total of 1,043 patients underwent 763 noninstrumented surgeries (discectomies, decompressions) and 280 instrumented (TLIF) procedures. The mean age was 52.2 years with male:female ratio of 1.08:1. Three infections were encountered with fusion surgeries (mean detection time, 7 days). All three required wound wash and debridement with one patient requiring unilateral implant removal. Additional direct cost due to infection was $2,678 per 100 MISS-TLIF. SSI increased hospital expenditure per patient 1.5-fold after instrumented MISS. Conclusions: Overall infection rate after MISS was 0.29%, with SSI rate of 0% in non-instrumented MISS and 1.07% with instrumented MISS. MISS can markedly reduce the SSI rate and can be an effective tool to minimize hospital costs.

Current Status of the Use of Salvaged Blood in Metastatic Spine Tumour Surgery

Naresh Kumar,Nivetha Ravikumar,Joel Yong Hao Tan,Kutbuddin Akbary,Ravish Shammi Patel,Rajesh Kannan 대한척추신경외과학회 2018 Neurospine Vol.15 No.3

To review the current status of salvaged blood transfusion (SBT) in metastatic spine tumour surgery (MSTS), with regard to its safety and efficacy, contraindications, and adverse effects. We also aimed to establish that the safety and adverse event profile of SBT is comparable and at least equal to that of allogeneic blood transfusion. MEDLINE and Scopus were used to search for relevant articles, based on keywords such as “cancer surgery,” “salvaged blood,” and “circulating tumor cells.” We found 159 articles, of which 55 were relevant; 20 of those were excluded because they used other blood conservation techniques in addition to cell salvage. Five articles were manually selected from reference lists. In total, 40 articles were reviewed. There is sufficient evidence of the clinical safety of using salvaged blood in oncological surgery. SBT decreases the risk of postoperative infections and tumour recurrence. However, there are some limitations regarding its clinical applications, as it cannot be employed in cases of sepsis. In this review, we established that earlier studies supported the use of salvaged blood from a cell saver in conjunction with a leukocyte depletion filter (LDF). Furthermore, we highlight the recent emergence of sufficient evidence supporting the use of intraoperative cell salvage without an LDF in MSTS.