Proposal for a surrogate surgical invasiveness score to obtain a 'post hoc' quantification of surgical stress and tissue trauma in the context of postoperative outcome assessments

Overview of Methods to Quantify Invasiveness of Surgical Approaches in Orthopedic Surgery—A Scoping Review

Background

There is a trend toward minimally invasive and more automated procedures in orthopedic surgery. An important aspect in the further development of these techniques is the quantitative assessment of the surgical approach. The aim of this scoping review is to deliver a structured overview on the currently used methods for quantitative analysis of a surgical approaches' invasiveness in orthopedic procedures. The compiled metrics presented in the herein study can serve as the basis for digitization of surgery and advanced computational methods that focus on optimizing surgical procedures.

Methods

We performed a blinded literature search in November 2020. In-vivo and ex-vivo studies that quantitatively assess the invasiveness of the surgical approach were included with a special focus on radiological methods. We excluded studies using exclusively one or multiple of the following parameters: risk of reoperation, risk of dislocation, risk of infection, risk of patient-reported nerve injury, rate of thromboembolic event, function, length of stay, blood loss, pain, operation time.

Results

The final selection included 51 articles. In the included papers, approaches to 8 different anatomical structures were investigated, the majority of which examined procedures of the hip (57%) and the spine (29%). The different modalities to measure the invasiveness were categorized into three major groups “biological” (23 papers), “radiological” (25), “measured in-situ” (14) and their use “in-vivo” or “ex-vivo” was analyzed. Additionally, we explain the basic principles of each modality and match it to the anatomical structures it has been used on.

Discussion

An ideal metric used to quantify the invasiveness of a surgical approach should be accurate, cost-effective, non-invasive, comprehensive and integratable into the clinical workflow. We find that the radiological methods best meet such criteria. However, radiological metrics can be more prone to confounders such as coexisting pathologies than in-situ measurements but are non-invasive and possible to perform in-vivo. Additionally, radiological metrics require substantial expertise and are not cost-effective. Owed to their high accuracy and low invasiveness, radiological methods are, in our opinion, the best suited for computational applications optimizing surgical procedures. The key to quantify a surgical approach's invasiveness lies in the integration of multiple metrics.

Major Complications Independently Increase Long-Term Mortality After Pancreatoduodenectomy for Cancer

BACKGROUND

Postoperative major morbidity has been associated with worse survival gastrointestinal tumors. This association remains controversial in pancreatic cancer (PC). We analyzed whether major complications after surgical resection affect long-term survival.

METHODS

Records of all PC patients resected from 2007 to 2015 were reviewed. Major morbidity was defined as any grade-3 or higher 30-day complications, per the Clavien-Dindo Classification. Patients who died within 90 days after surgery were excluded from survival analysis.

RESULTS

Of 616 patients, 81.7% underwent pancreatoduodenectomy (PD) and 18.3% distal pancreatectomy (DP). Major complications occurred in 19.1% after PD and 15.9% after DP. In patients who survived > 90 days, the likelihood of receiving adjuvant treatment was 43.9% if major complications had occurred, vs. 68.5% if not (p < 0.001), and those who received it started the treatment median 10 days later compared with uncomplicated patients (median 60 days (50-72) vs. 50 days (41-61), p = 0.001). By univariate analysis, in addition to the conventional pathology-related prognostic determinants and the receipt of adjuvant treatment, major complications worsened long-term survival after PD (median OS 26 months vs. 15, p = 0.008). A difference was also seen after DP, but it did not reach statistical significance, likely related to the small sample size (median OS 33 months vs. 18, p = 0.189). At multivariate analysis for PD, major postoperative complications remained independently associated with worse survival [HR 1.37, 95%CI (1.01-1.86)].

CONCLUSIONS

Major surgical complications after pancreaticoduodenectomy are associated with worse long-term survival in pancreatic cancer. This effect is independent of the receipt of adjuvant treatment.

Basic Features and Clinical Applicability of 'Preliminary Universal Surgical Invasiveness Score' (pUSIS): A Multi-Centre Pilot Study

OBJECTIVE

There is still a lack of a universally applicable and comprehensive scoring system for documenting the invasiveness of surgical procedures. The proposed preliminary 'Universal Surgical Invasiveness Score' (pUSIS) is intended to fill this gap.

METHODS

We used the recently developed pUSIS to obtain values from 8 types of surgery and 80 individual interventions. The results were analysed using descriptive statistical methods. The degree of difficulty on a scale from 0 (very easy) to 10 (extremely difficult) and time expenditures for assessing pUSIS were documented.

RESULTS

Individual pUSIS values ranged from 8 in a laparoscopic cholecystectomy case to 36 in a total hip replacement case. The lowest median pUSIS value of 11.5 was found for laparoscopic cholecystectomy and the highest value of 24.5 was found for open thoracic surgery. The correlation between pUSIS values and the duration of surgery resulted in a tight linear regression (R2=0.6419). The lowest mean (±SD) difficulty level to obtain pUSIS values was 1.6±0.6 for sleeve gastrectomy and the highest one was 2.9±0.6 for knee replacement. The duration to finalise the calculations was 4.1±1.1 min for video-assisted thoracoscopy (VATS) and 9.4±1.3 min for sleeve gastrectomy.

CONCLUSION

We concluded that pUSIS has the potential to be a useful, simply obtainable and universal assessment tool for quantification of the magnitude and invasiveness of individual surgical operations and can serve as a means to quantify surgical interventions for outcome research and evaluate surgical performance.