The Learning Curve of Transareola Single-site Laparoendoscopic Thyroidectomy: CUSUM Analysis of a Single Surgeon's Experience

Definition of learning curve for thyroidectomy: systematic review on the different approaches

Background

Thyroidectomy is one of the most common surgical procedures carried out worldwide and it has evolved in recent years with alternative approaches. With the advent of minimally invasive techniques, the learning curve (LC) concept has become a fundamental "dogma".

Methods

A literature search, according to the PRISMA guidelines, was performed via PubMed (MEDLINE), Scopus, Cochrane Library, EMBASE, and Web of Science. Only studies assessing the learning process to thyroidectomy (including hemi- and total thyroidectomy), reporting a minimum of 30 procedures and describing clearly the minimum number of performances required to achieve proficiency and the main evaluation items used to establish it, were included. Conventional, endoscopic and robotic approaches were separately analyzed. Only English-language studies were considered.

Results

Forty-five relevant studies were selected for the analysis [respectively 16 concerning robotic thyroidectomy (RT), 22 endoscopic thyroidectomy (ET), 6 mini-invasive video assisted thyroidectomy (MIVAT), 1 conventional thyroidectomy (CT)]. The number of procedures required for a single surgeon to achieve competence and the parameters used to define surgical proficiency were fully investigated for each individual technique.

Conclusions

Our research shows how the current literature lacks an objective definition of the LC concept. The heterogeneity of analysis methodologies and parameters evaluated, the various surgical techniques and training background of single surgeons, make it impossible to draw univocal results. Future studies should consider confounding factors and establish criteria that should be consensually recognized in the assessment of surgical performances and skills.

Learning curve for laparoendoscopic single-site radical hysterectomy using the "chopstick" technique: a retrospective cohort study

BACKGROUND

Laparoendoscopic single-site surgery (LESS), as a promising minimally invasive surgery, is confronted with the obstacle of the "chopstick effect" which limits its further application. The "chopstick" technique is characterized by the usage of instruments of parallel and equal length, and in operations relying on double-fulcrum and unique surgeon position can play a key role in overcoming the above disadvantage effect. This study sought to explore the learning curve for the use of the novel "chopstick" technique in laparoendoscopic single-site radical hysterectomy (LESS-RH) and evaluate the technique's practicability.

METHODS

Consecutive cervical cancer patients who underwent LESS-RH with the "chopstick" technique by a surgeon with rich experience in laparoscopy from November 2016 to September 2018 were included in the study. The learning curve of his surgeries with the "chopstick" technique was evaluated using the cumulative summation (CUSUM) method by analyzing operation time (OT) which was the surrogate indicator of surgical ability. The patients were divided into Phase I and Phase II based on the learning curve peak, whose demographic and perioperative characteristics, such as tumor Federation International of Gynecology and Obstetrics (FIGO) stage and histology, operation time, blood loss, and complications were collected and analyzed.

RESULTS

The mean OT was 231.5 min (range, 115-355 min). The division of the learning curve based on OT occurred after the first 15 cases were finished, dividing Phase I and Phase II. The mean OT for Phase I (259 min) was significantly longer than that of Phase II (219 min) (P=0.02). Only 1 intraoperative complication occurred in Phase I, and none occurred in Phase II. Major postoperative complications occurred more frequently in Phase I (N=3) than in Phase II (N=0). No significant differences were observed in terms of lymph nodes, blood loss, or pathological features.

CONCLUSIONS

The "chopstick" technique may help surgeons obtain stable LESS surgical performance through a relatively short learning curve, even in some complex surgeries, such as radical hysterectomy.

[Learning curves in acquisition of experience for new technologies]

OBJECTIVE

Analysis of national and foreign trials investigating accumulation of experience in innovative technologies using the learning curves.

MATERIAL AND METHODS. S

Earching for Russian-language manuscripts was carried out within the references of the articles and in the ELIBRARY database. Foreign trials were selected from the PubMed database according to the keywords «learning curves in surgical practice». The discovered publications were studied for accordance with the objectives of this study.

RESULTS

Accumulation of experience in new technologies by using of learning curves is valuable to improve the training, determine duration of development of new technology and the factors affecting its characteristics.

CONCLUSION

The method is high-quality for comprehensive analysis of experience accumulation in new surgical technologies.

[Evaluation of experience acquisition in video-assisted hemithyroidectomy]

OBJECTIVE

To determine validity and adequacy of the assessment of experience acquisition in video-assisted hemithyroidectomy, to compare surgical outcomes at the learning stage and in delayed period.

MATERIAL AND METHODS

Experience acquisition was studied via assessment of the duration of video-assisted hemithyroidectomy in 67 patients who were operated by the same surgeon. Time of surgery was analyzed through between-group comparison of surgical outcomes. These groups were defined arbitrarily, in exponential fashion, using the logarithm method and moving average. Risks of failure regarding duration of surgery and postoperative complications were investigated using CUSUM analysis.

RESULTS

Minimum period of experience accumulation in video-assisted hemithyroidectomy (26 procedures) was determined using logarithmic analysis, maximum period (66 interventions) - using CUSUM analysis. Other approaches also showed sharp nature of the learning curve.CUSUM analysis of failures at the learning stage showed 2-fold decrease of their probability after 66 operations. However, even experience acquisitiondoes not exclude risk of failures in hemithyroidectomy.

CONCLUSION

Arbitrary division of the cohort of patients seems to be unreasonable because clear number of operations necessary to achieve sustainable results does not follow it.Mathematical methods adequately reflect experience accumulation and allow determining the required number of interventions for stable results and minimum complication rate.

Value of the cumulative sum test for the assessment of a learning curve: Application to the introduction of patient-specific instrumentation for total knee arthroplasty in an academic department

BACKGROUND

The purpose of the study was to use the cumulative summation (CUSUM) test to assess the learning curve during the introduction of a new surgical technique (patient-specific instrumentation) in total knee arthroplasty (TKA) in an academic department.

METHODS

The first 50TKAs operated on at an academic department using patient-specific templates (PSTs) were scheduled to enter the study. All patients had a preoperative computed tomography scan evaluation to plan bone resections. The PSTs were positioned intraoperatively according to the best-fit technique and their three-dimensional orientation was recorded by a navigation system. The position of the femur and tibia PST was compared to the planned position for four items for each component: coronal and sagittal orientation, medial and lateral height of resection. Items were summarized to obtain knee, femur and tibia PST scores, respectively. These scores were plotted according to chronological order and included in a CUSUM analysis. The tested hypothesis was that the PST process for TKA was immediately under control after its introduction.

RESULTS

CUSUM test showed that positioning of the PST significantly differed from the target throughout the study. There was a significant difference between all scores and the maximal score. No case obtained the maximal score of eight points. The study was interrupted after 20 cases because of this negative evaluation.

CONCLUSION

The CUSUM test is effective in monitoring the learning curve when introducing a new surgical procedure. Introducing PST for TKA in an academic department may be associated with a long-lasting learning curve. The study was registered on the clinical.gov website (Identifier NCT02429245).