Long-term Oncologic Outcome of Postoperative Complications After Colorectal Cancer Surgery

Impact of Preoperative and Intraoperative Factors on Postoperative Outcomes in Patients with Colorectal Cancer: A 10-Year Retrospective Study

BACKGROUND AND OBJECTIVES

Colorectal cancer is a major contributor to global cancer morbidity and mortality. Surgical resection remains the cornerstone of treatment, but postoperative complications can significantly affect patient outcomes. Identifying factors that influence postoperative morbidity and mortality is crucial for optimizing patient care. This study aims to evaluate the impact of preoperative, intraoperative, and postoperative factors on surgical outcomes in patients with colorectal cancer.

METHODS

A retrospective cohort study was conducted on 688 patients who underwent colorectal cancer surgery within a 10-year period. Data collected included demographic information, comorbidities, laboratory values, surgical details, and postoperative outcomes. Statistical analyses were performed using chi-square tests for categorical variables and t-tests for continuous variables. Multivariate logistic regression was used to identify independent predictors of postoperative complications and mortality.

RESULTS

Postoperative complications occurred in 28.5% of patients, and the 30-day mortality rate was 5.2%. Preoperative factors such as elevated C-reactive protein (CRP) levels (p < 0.001), low albumin levels (p = 0.003), a high American Society of Anesthesiologists (ASA) score (p < 0.001), and presence of comorbidities like diabetes and hypertension (p = 0.005) were significantly associated with increased postoperative complications. Intraoperative factors such as blood loss greater than 500 mL (p < 0.001) and longer operative time (p = 0.021) were also significant predictors of adverse outcomes. Multivariate analysis identified elevated CRP (OR 2.1, 95% CI 1.5-2.9), low albumin (OR 1.8, 95% CI 1.3-2.5), and blood loss > 500 mL (OR 2.4, 95% CI 1.7-3.4) as independent predictors of postoperative complications.

CONCLUSIONS

Preoperative inflammatory markers, nutritional status, ASA score, comorbidities, and intraoperative factors like blood loss significantly influence postoperative outcomes in colorectal cancer surgery. Recognizing these risk factors allows for better preoperative optimization and surgical planning, potentially reducing postoperative morbidity and mortality.

Effect of postoperative complications on 5-year survival following laparoscopic surgery for resectable colorectal cancer: a retrospective study

PURPOSE

The purpose of this study was to investigate the effects of postoperative complications on long-term survival after laparoscopic surgery for resectable colorectal cancer.

METHODS

We retrospectively included 204 patients who underwent laparoscopic surgery for colorectal cancer from January 2016 to June 2020.

RESULTS

Overall, 68 (33.3%) patients had postoperative complications, twelve (17.6%) of which were classified as Clavien-Dindo class 3a or higher. The 5-year overall survival rate of the non-complication and complication groups were 93.0% and 81.7%, respectively (p = 0.048; Kaplan-Meier analysis and log-rank test), and those among patients with stage III disease were 87.0% and 61.3%, respectively (p = 0.045). The 5-year disease-free survival rates were 85.6% and 77.4%, respectively (p = 0.042). Multivariable Cox proportional-hazards analysis revealed that nodal stage (hazard ratio, 8.392; 95% confidence interval, 1.892-37.175; p = 0.005) was an independent prognostic factor for overall survival, and postoperative complications (hazard ratio, 2.996; 95% confidence interval, 1.076-8.340; p = 0.036) were independent prognostic factors for disease-free survival.

CONCLUSION

Postoperative complications were associated with poor oncological outcomes, especially among patients with stage III colorectal cancer, and independent prognostic factors for disease-free survival.

The role of robotic-assisted surgery in the management of rectal cancer: a systematic review and meta-analysis

BACKGROUND

Rectal cancer poses a significant global health burden. There is a lack of concrete evidence concerning the benefits of robotic-assisted surgery (RAS) for rectal cancer surgery as compared to laparoscopic and open techniques. To address this gap, we conducted a meta-analysis to assess the intraoperative, postoperative, and safety outcomes of robotic surgery in this context.

RESEARCH METHODOLOGY

A search of MEDLINE, Scopus and the Cochrane Library. Randomized and non-randomized studies up to February 2, 2024 comparing robotic surgery versus laparoscopic or open surgery for rectal cancer. The outcomes of interest were operative time, blood loss, harvested lymph nodes, conversion rate, postoperative hospital stay, survival to hospital discharge, urinary retention rate, and anastomotic leakage rate. A random-effects meta-analysis was performed to pool means and dichotomous data to derive weighted mean differences and odds ratios, respectively.

RESULTS

A total of 56 studies were shortlisted after the study selection process with a total of 25 458 rectal cancer patients. From the intraoperative outcomes, RAS was significantly associated with an increased operative time (WMD: 41.04, P <0.00001), decreased blood loss (WMD: -24.56, P <0.00001), decreased conversion rates (OR: 0.39, P <0.00001), lesser stay at the hospital (WMD: -1.93, P <0.00001), and no difference was found in lymph nodes harvested. Similarly, RAS group had a significantly greater survival to hospital discharge (OR: 1.90, P =0.04), decreased urinary retention rate (OR: 0.59, P =0.002), and no difference was seen in anastomotic leakage rate.

CONCLUSION

RAS demonstrates favorable outcomes for rectal cancer patients, contributing to global prevention and control efforts, health promotion, and addressing non-communicable disease risk factors. Further research and public awareness are needed to optimize RAS utilization in this context.

Postoperative Complications Result in Poor Oncological Outcomes: What Is the Evidence?

The majority of patients with solid tumors undergo a curative resection of their tumor burden. However, the reported rate of postoperative complications varies widely, ranging from 10% to 70%. This narrative review aims to determine the impact of postoperative complications on recurrence and overall survival rates following elective cancer surgeries, thereby providing valuable insights into perioperative cancer care. A systematic electronic search of published studies and meta-analyses from January 2000 to August 2023 was conducted to examine the effect of postoperative complications on long-term survival after cancer surgeries. This comprehensive search identified fifty-one eligible studies and nine meta-analyses for review. Recurrence-free survival (RFS) and overall survival (OS) rates were extracted from the selected studies. Additionally, other oncological outcomes, such as recurrence and cancer-specific survival rates, were noted when RFS and OS were not reported as primary outcomes. Pooled hazard ratios and 95% confidence intervals were recorded from the meta-analyses, ensuring the robustness of the data. The analysis revealed that long-term cancer outcomes progressively worsen, from patients with no postoperative complications to those with minor postoperative complications (Clavien-Dindo grade ≤ II) and further to those with major postoperative complications (Clavien-Dindo grade III-IV), irrespective of cancer type. This study underscores the detrimental effect of postoperative complications on long-term oncological outcomes, particularly after thoracoabdominal surgeries. Importantly, we found a significant gap in the data regarding postoperative complications in surface and soft tissue surgical procedures, highlighting the need for further research in this area.

Risk Factors of Postoperative Complication and Hospital Mortality after Colorectal Perforation Surgery

Objectives

Colorectal perforation is associated with high morbidity and mortality rates after surgery. We investigated various clinical features of patients who underwent emergency surgery for colorectal perforation and explored the risk factors for postoperative complications and hospital mortality.

Methods

Data from 147 patients who underwent surgery for colorectal perforation were retrospectively reviewed. We investigated various clinical and operative factors, including inflammation-based prognostic scores (IBPSs), and evaluated the risk factors for postoperative complications and hospital mortality due to colorectal perforation.

Results

Among 147 patients, the most frequent postoperative complication was wound infection (32 cases, 21.8%), followed by intra-abdominal abscesses (27 cases, 18.4%) after surgery for colorectal perforation. Time from onset to surgery ≥ 2 days (Hazard ratio [HR] = 2.810, p = 0.0383) and prognostic nutritional index (PNI) < 30 (HR = 3.190, p = 0.0488) were identified as risk factors for intra-abdominal abscess, while neutrophil-lymphocyte ratio (NLR) < 6.15 (HR = 5.020, p = 0.0009) was identified as a risk factor for wound infection. Time from onset to surgery ≥ 2 days (HR = 7.713, p = 0.0492), severe postoperative complications (Clavien-Dindo grade ≥ IIIa) (HR = 10.98, p = 0.0281), and platelet-lymphocyte ratio (PLR) < 144 (HR = 18.84, p = 0.0190) were independent predictive factors for hospital mortality.

Conclusions

Time from onset to surgery and IBPSs such as PNI, NLR, and PLR, may be associated with postoperative complications and hospital mortality due to colorectal perforation.

Accelerated enhanced recovery after colon cancer surgery with discharge within one day after surgery: a systematic review

BACKGROUND

Recent studies have demonstrated that accelerated enhanced recovery after colorectal surgery is feasible for specific patient populations. The accelerated enhanced recovery protocols (ERP) tend to vary, and the majority of studies included a small study population. This hampers defining the optimal protocol and establishing the potential benefits. This systematic review aimed to determine the effect of accelerated ERPs with intended discharge within one day after surgery.

METHODS

PubMed (MEDLINE), Embase, Cochrane and Web of Science databases were searched using the following search terms: colon cancer, colon surgery, accelerated recovery, fast track recovery, enhanced recovery after surgery. Clinical trials published between January 2005 - February 2023, written in English or Dutch comparing accelerated ERPs to Enhanced Recovery After Surgery (ERAS) care for adult patients undergoing elective laparoscopic or robotic surgery for colon cancer were eligible for inclusion.

RESULTS

Thirteen studies, including one RCT were included. Accelerated ERPs after colorectal surgery was possible as LOS was shorter; 14 h to 3.4 days, and complication rate varied from 0-35.7% and readmission rate was 0-17% in the accelerated ERP groups. Risk of bias was serious or critical in most of the included studies.

CONCLUSIONS

Accelerated ERPs may not yet be considered the new standard of care as the current data is heterogenous, and data on important outcome measures is scarce. Nonetheless, the decreased LOS suggests that accelerated recovery is possible for selected patients. In addition, the complication and readmission rates were comparable to ERAS care, suggesting that accelerated recovery could be safe.

Predictive value of POSSUM scoring system for postoperative complications and mortality in elderly patients with colorectal cancer

BACKGROUND

The POSSUM scoring system, widely employed in assessing surgical risks, offers a simplified and objective approach for the prediction of complications and mortality in patient. Despite its effectiveness in various surgical fields, including orthopedics and cardiovascular surgery, yet its utilization in elderly patients undergoing colorectal cancer surgery is infrequent.

OBJECTIVE

To analyze the predictive value of POSSUM scoring system for postoperative complications and mortality in elderly with colorectal cancer.

METHODS

306 elderly colorectal cancer patients were grouped according to the complications and death within 30 days after surgery. Among them, 108 cases in complication group, 198 cases in non-complication group, 16 cases in death group and 290 cases in survival group. POSSUM scores of all subjects were obtained and its predictive value for postoperative complications and mortality of elderly was conducted by ROC curve.

RESULTS

No apparent difference were observed in complications and mortality among patients with different disease types, operation types and operation timing (P> 0.05). The R2 in complication group was higher than non-complication group (P< 0.05). The R1 in death group were higher than survival group (P< 0.05). The AUC of R2 for predicting postoperative complications was 0.955 with a sensitivity of 88.89% and a specificity of 94.44% and the AUC of R1 for evaluating postoperative mortality of elderly with colorectal cancer was 0.783 with a sensitivity of 56.25% and a specificity of 82.93%.

CONCLUSION

POSSUM score system has a certain predictive value for postoperative complications and mortality in elderly with colorectal cancer. However, the predicted mortality rate is higher than actual mortality rate.

Effect of serum lactate dehydrogenase-to-albumin ratio (LAR) on the short-term outcomes and long-term prognosis of colorectal cancer after radical surgery

BACKGROUND

Whether serum lactate dehydrogenase-to-albumin ratio (LAR) influenced the outcomes of colorectal cancer (CRC) patients after radical surgery remained unclear. Therefore, this study sought to examine how LAR influences the short-term and long-term outcomes of CRC patients who have undergone radical surgery.

METHODS

This study retrospectively included CRC patients who underwent radical resection between January 2011 and January 2020. We compared short-term outcomes, as well as overall survival (OS) and disease-free survival (DFS), among various groups. Both univariate and multivariate logistic regression analyses were utilized to pinpoint independent risk factors associated with overall complications and major complications. Moreover, Cox regression analysis were conducted for OS and DFS. Odds ratio (OR) and Hazard ratio (HR) were adjusted.

RESULTS

This study encompassed a cohort of 3868 patients. 3440 patients were in the low LAR group and 428 patients constituted the high LAR group. In the high LAR group, patients experienced significantly longer operative times (p < 0.01), larger intraoperative blood loss (p < 0.01), and extended postoperative hospital stays (p < 0.01). Additionally, the incidence of both overall complications (p < 0.01) and major complications (p < 0.01) was higher in the high LAR group compared to the low LAR group. Furthermore, LAR was emerged as an independent prognostic factor for overall complications [OR/95% CI: (1.555/1.237 to 1.954), p < 0.01] and major complications [OR/95% CI: (2.178/1.279 to 3.707), p < 0.01]. As for long-term survival, the high LAR group had worse OS in stage II (p < 0.01) and stage III (p < 0.01). In both stage II (p < 0.01) and stage III (p < 0.01), the high LAR group exhibited poorer DFS. Additionally, according to Cox regression analysis, LAR was identified as an independent predictor for both OS [HR/95% CI: (1.930/1.554 to 2.398), p < 0.01] and DFS [HR/95% CI: (1.750/1.427 to 2.146), p < 0.01].

CONCLUSION

LAR emerged as an independent predictor not only for overall complications and major complications but also for both OS and DFS, highlighting its significance and deserving the attention of surgeons.

International Society of University Colon and Rectal Surgeons survey of surgeons' preference on rectal cancer treatment

PURPOSE

Rectal cancer treatment has a wide range of possible approaches from radical extirpative surgery to nonoperative watchful waiting following chemoradiotherapy, with or without, additional chemotherapy. Our goal was to assess the personal opinion of active practicing surgeons on rectal cancer treatment if he/she was the patient.

METHODS

A panel of the International Society of University Colon and Rectal Surgeons (ISUCRS) selected 10 questions that were included in a questionnaire that included other items including demographics. The questionnaire was distributed electronically to ISUCRS fellows and other surgeons included in our database and remained open from April 16 to 28, 2020.

RESULTS

One hundred sixty-three specialists completed the survey. The majority of surgeons (n=65, 39.9%) chose the minimally invasive (laparoscopic) surgery for their personal treatment of rectal cancer. For low-lying rectal cancer T1 and T2, the treatment choice was standard chemoradiation+local excision (n=60, 36.8%) followed by local excision±chemoradiotherapy if needed (n=55, 33.7%). In regards to locally advanced low rectal cancer T3 or greater, the preference of the responders was for laparoscopic surgery (n=65, 39.9%). We found a statistically significant relationship between surgeons' age and their preference for minimally invasive techniques demonstrating an age-based bias on senior surgeons' inclination toward open approach.

CONCLUSION

Our survey reveals an age-based preference by surgeons for minimally invasive surgical techniques as well as organ-preserving techniques for personal treatment of treating rectal cancer. Only 1/4 of specialists do adhere to the international guidelines for treating early rectal cancer.

Robotic versus Laparoscopic Total Mesorectal Excision Surgery in Rectal Cancer: Analysis of Medium-Term Oncological Outcomes

Background. Robotic systems can overcome some limitations of laparoscopic total mesorectal excision (L-TME), thus improving the quality of the surgery. So far, many studies have reported the technical feasibility and short-term oncological results of robotic total mesorectal excision (R-TME) in treating rectal cancer (RC); however, only a few evaluated the survival and long-term oncological outcomes. The following study compared the medium-term oncological data, 3-year overall survival (OS), and disease-free survival (DFS) of L-TME and R-TME in patients with rectal cancer. Methods. In this retrospective study, records of patients (patients with stage I-III rectal cancer) who underwent surgery (127 cases of L-TME and 148 cases of R-TME) at the Gansu Provincial Hospital between June 2016 and March 2018 were included in the analysis. Kaplan-Meier analysis evaluated the 3-year OS and DFS for all patients treated with curative intent. Results. The conversion rate was significantly higher, and the postoperative hospital stay was significantly longer in the L-TME group than in the R-TME group (all P<.05). Major complications were significantly lower in the robotic group (P<.05). The 3-year DFS rate (for all stages) was 74.8% for L-TME and 85.8% for R-TME (P = .021). For disease stage III, the 3-year DFS and OS were significantly higher in the R-TME group (P<.05). Conclusion. R-TME can achieve better oncological outcomes and is more beneficial for RC patients compared with L-TME, especially for those with stage III rectal cancers. Nevertheless, further randomized controlled trials and a longer follow-up period are needed to confirm these findings.

Do postoperative infectious complications really affect long-term survival in colorectal cancer surgery? A multicenter retrospective cohort study

Aim

To investigate the impact of postoperative infection (PI), surgical site infection, and remote infection (RI), on long-term outcomes in patients with colorectal cancer (CRC).

Methods

The Japan Society for Surgical Infection conducted a multicenter retrospective cohort study involving 1817 curative stage I/II/III CRC patients from April 2013 to March 2015. Patients were divided into the No-PI group and the PI group. We examined the association between PI and oncological outcomes for cancer-specific survival (CSS) and overall survival (OS) using Cox proportional hazards models and propensity score matching.

Results

Two hundred and ninety-nine patients (16.5%) had PIs. The 5-year CSS and OS rates in the No-PI and PI groups were 92.8% and 87.6%, and 87.4% and 83.8%, respectively. Both the Cox proportional hazards models and propensity score matching demonstrated a significantly worse prognosis in the PI group than that in the No-PI group for CSS (hazard ratio: 1.60; 95% confidence interval: 1.10-2.34; P = .015 and P = .031, respectively) but not for OS. RI and the PI severity were not associated with oncological outcomes. The presence of PI abolished the survival benefit of adjuvant chemotherapy.

Conclusions

These results suggest that PI after curative CRC surgery is associated with impaired oncological outcomes. This survival disadvantage of PI was primarily derived from surgical site infection, not RI, and PI induced lower efficacy of adjuvant chemotherapy. Strategies to prevent PI and implement appropriate postoperative treatment may improve the quality of care and oncological outcomes in patients undergoing curative CRC surgery.

Robotic surgery for colorectal cancer

Background: Robotic surgical systems were created partly to solve several constraints of laparoscopic surgery and to offer technical advantages. With a substantial body of evidence demonstrating its efficacy in rectal cancer treatment, robotic surgery will soon become another conventional treatment. However, further investigations and randomized trials focusing on primary endpoints are necessary to establish some advantages of robot-assisted colon surgery.Current Concepts: Da Vinci Single-Site and SP platforms (Intuitive Surgical Inc.) were developed to overcome the shortcomings of single-port laparoscopic surgery. Despite the currently insufficient evidence, it seems that the SP platform addresses several limitations of single-port transabdominal or transanal surgery. Robotic transanal minimally invasive surgery and total mesorectal excision were developed to overcome conventional platforms’ limitations, using wristed instrumentation to enhance dexterity and ergonomics. Studies on the effectiveness and viability of this novel approach are ongoing. The near-infrared fluorescence technique, real-time stereotactic navigation technology, and other surgical data platforms based on artificial intelligence incorporated into the robotic system will play an important role in improving outcomes.Discussion and Conclusion: Robotic systems for advanced colorectal cancer offer technical advantages for complex and precise surgeries. If robotic surgery costs are reduced by expanding its indications and enhancing competition among different robotic platforms, it will provide clinical benefits to more patients and reduce social healthcare costs.

Does Preoperative Waiting Time Affect the Short-Term Outcomes and Prognosis of Colorectal Cancer Patients? A Retrospective Study from the West of China

PURPOSE

The purpose of this study is to analyze the effect of preoperative waiting time on the short-term outcomes and prognosis in colorectal cancer (CRC) patients.

METHODS

We retrospectively analyzed 3744 CRC patients who underwent primary CRC surgery at a single clinical medical center from Jan 2011 to Jan 2020. The baseline information, short-term outcomes, overall survival (OS), and disease-free survival (DFS) were compared among the short-waiting group, the intermediate-waiting group, and the long-waiting group.

RESULTS

A total of 3744 eligible CRC patients were enrolled for analysis. There were no significant differences in all of the baseline information and short-term outcomes among the three groups. In multivariate analysis, older age (OS: p=0.000, HR = 1.947, 95% CI = 1.631-2.324; DFS: p=0.000, HR = 1.693, 95% CI = 1.445-1.983), advanced clinical stage (OS: p=0.000, HR = 1.301, 95% CI = 1.161-1.457; DFS: p=0.000, HR = 1.262, 95% CI = 1.139-1.400), overall complications (OS: p=0.000, HR = 1.613, 95% CI = 1.303-1.895; DFS: p=0.000, HR = 1.560, 95% CI = 1.312-1.855), and major complications (OS: p=0.001, HR = 1.812, 95% CI = 1.338-2.945; DFS: p=0.006, HR = 1.647, 95% CI = 1.153-2.352) were independent factors of OS and DFS. In addition, no significant difference was found in all stages (OS, p=0.203; DFS, p=0.108), stage I (OS, p=0.419; DFS, p=0.579), stage II (OS, p=0.465; DFS, p=0.385), or stage III (OS, p=0.539; DFS, p=0.259) in terms of OS and DFS among the three groups.

CONCLUSION

Preoperative waiting time did not affect the short-term outcomes or prognosis in CRC patients.

Surgical site infection after laparoscopic resection of colorectal cancer is associated with compromised long-term oncological outcome

Background

We evaluated the influence of infectious complications, particularly surgical site infection (SSI), on long-term oncological results after elective laparoscopic resection of colorectal cancer.

Methods

A total of 199 patients who underwent laparoscopic elective resection with negative resection margins for stage I–III colorectal cancer were retrospectively examined. The postoperative course was recorded based on hospital records, and cancer relapse was diagnosed based on radiological or pathological findings under a standardized follow-up program. The severity of complications was graded using Clavien-Dindo (CD) classification.

Results

SSI was found in 25 patients (12.6%), with 12 (6.0%) showing anastomotic leak. The postoperative relapse-free survival (RFS) rate was significantly lower in patients with SSI (49.2%) than in patients without SSI (87.2%, P<0.001). Differences in RFS were found after both colectomy and rectal resection (P<0.001 and P<0.001, respectively). RFS did not differ between patients who had major SSI CD (grade III) and those who had minor SSI CD (grades I or II). Multivariate Cox regression analysis identified the occurrence of SSI and pathological stage as independent co-factors for RFS (P<0.001 and P=0.003).

Conclusion

These results suggest that postoperative SSI compromises long-term oncological results after laparoscopic colorectal resection. Further improvements in surgical technique and refinements in perioperative care may improve long-term oncological results.

Surgical safety in the COVID-19 era: present and future considerations

The impacts of coronavirus disease 2019 (COVID-19) have been globally paradigm shifting in all aspects. Surgeons have experienced unprecedented changes regarding operation schedules, preparations before surgery, and the precautions needed both during and after surgery. Many medical centers simultaneously reported a decrease in their numbers of surgeries, whether they were elective or emergent, or for cancerous or benign resections. However, accumulated surgical outcomes from the last 2 years of experience presented postoperative morbidity and mortality data that were comparable to the pre-pandemic era, whether in elective or urgent settings. Although COVID-19 showed a significant association with postoperative morbidity and mortality, the majority of noninfected patients could be treated successfully with stringent mitigation protocols. Initially recommended to be avoided at the start of the pandemic, minimally invasive surgery seems to be safe and feasible according to reported surgical outcomes. Numerous sets of guidelines have now been produced from medical societies and adhering to the basic precautions has been found to be practicable. It is crucial that health care systems and surgical staff remain vigilant and attentive to the ever-changing situation in this pandemic in order to provide optimal medical support to their patients.

Current status and role of robotic approach in patients with low-lying rectal cancer

Utilization of robotic surgical systems has increased over the years. Robotic surgery is presumed to have advantages of enhanced visualization, improved dexterity, and reduced tremor, which is purported to be more suitable for rectal cancer surgery in a confined space than laparoscopic or open surgery. However, evidence supporting improved clinical and oncologic outcomes after robotic surgery remains controversial and limited despite the widespread adoption of robotic surgical systems. To date, numerous observational studies and a few randomized controlled trials have failed to demonstrate that short-term, oncological, and functional outcomes after a robotic surgery are superior to those of laparoscopic surgery for low rectal cancer patients. The objective of this review is to summarize the current state of robotic surgery and its impact on low-lying rectal cancer.

Modified Clavien-Dindo-sink classification system for adolescent idiopathic scoliosis

PURPOSE

The Clavien-Dindosink (CDS) classification system provides more treatment-focused granularity than subjective methods of describing surgical complications; however, it has not been validated in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). The purpose of this study was to modify the CDS system for application in patients with AIS undergoing PSF to assess its inter- and intra-rater reliability for describing complications faced by this population.

METHODS

A review of all complications specific to patients with AIS captured in a large multicenter international database was performed. All complications were classified according to CDS, modified by addition of "prolonged initial hospital stay" as a criterion for Grade II. A survey of this complication list and an additional 20 clinical vignettes (sent out on two occasions) was sent to nine spinal deformity surgeons. Weighted kappa values were used to determine inter- and intra-rater reliability.

RESULTS

The Fleiss κ value for interrater reliability among 5 respondents grading all AIS complications was 0.8 (very good). For each grade, interrater reliability was very good, with an overall range of 0.8-1. The overall kappa value for intrarater reliability among eight respondents grading 20 vignettes was between 0.6 (good) and 0.9 (very good).

CONCLUSION

The modified CDS classification system has very good interrater and intrarater reliability in describing complications following PSF in patients with AIS. This system may be of greater utility for reporting outcomes than a "major" versus "minor" complication system and can serve as a valuable tool for improving surgical practices and patient outcomes in this population.

LEVEL OF EVIDENCE

IV case series.