Hand-assisted laparoscopic surgery versus open surgery for colorectal disease: a systematic review and meta-analysis

The Incidence and Nature of Adverse Medical Device Events in Dutch Hospitals: A Retrospective Patient Record Review Study

OBJECTIVES

Despite widespread use of medical devices and their increasing complexity, their contribution to unintended injury caused by healthcare (adverse events, AEs) remains relatively understudied. The aim of this study was to gain insight in the incidence and types of AEs involving medical devices (AMDEs).

METHODS

Data from two patient record studies for the identification of AEs were used. Identification of AMDEs was part of these studies. Patient records of 6894 admissions of a random sample of 20 hospitals in 2011/2012 and 19 hospitals in 2015/2016 were reviewed for AMDEs by trained nurses and physicians.

RESULTS

In 98.7% of the admissions, a medical device was used. Adverse events involving medical devices were present in 2.8% of the admissions, with 24% of the AMDEs being potentially preventable. Of all AEs, in 40%, medical devices were involved. Of all potentially preventable AEs, in 44%, medical devices were involved. Implants were most often involved in potentially preventable AMDEs.

CONCLUSIONS

Medical devices are substantially involved in potentially preventable AEs in hospitals. Research into AMDEs is of great importance because of the increasing use and complexity of medical devices. Based on patient records, most improvements could be made for placement of implants and prevention of infections related to medical devices. Safety and safe use of medical devices should be a subject of attention and further research.

Surgical outcomes of hybrid hand-assisted laparoscopic pelvic exenteration for locally advanced rectal cancer: Initial experience

INTRODUCTION

Hybrid hand-assisted laparoscopic surgery (HALS) combines better visualization of laparoscopic surgery with the advantages of open surgery. The aim of this study was to describe important technical considerations of HALS and to assess the feasibility of hybrid HALS pelvic exenteration (PE) for primary advanced rectal cancer.

METHODS

From May 2012 to August 2018, we retrospectively analyzed 11 patients who underwent PE for primary advanced rectal cancer (< 10 cm from the anal verge). Patients were divided into the open PE group (n = 5) and the hybrid HALS PE group (n = 6).

RESULTS

There was no significant difference in patient characteristics between the two groups, and all included patients were male. Tumor invasion to adjacent organs was mostly anterior invasion. In addition, four patients (66%) in the hybrid HALS PE group and two (40%) in the open PE group received neoadjuvant therapy (P = .3).

CONCLUSION

Compared to open surgery, hybrid HALS has the advantages of less bleeding and less invasion, and can achieve the same results in the short-term. It was a reasonable procedure which was easy and safe dissection of internal iliac vessels and dorsal vein complex. Thus, hybrid HALS may become a useful approach for PE.

A meta-analysis comparing hand-assisted laparoscopic right hemicolectomy and open right hemicolectomy for right-sided colon cancer

Background

Mini-invasive colorectal cancer surgery was adopted widely in recent years. This meta-analysis aimed to compare hand-assisted laparoscopic surgery (HALS) with open right hemicolectomy (OS) for malignant disease.

Methods

PRISMA guidelines with random effects model were adopted using Review Manager Version 5.3 for pooled estimates.

Results

Seven studies that involved 506 patients were included. Compared to OS, HALS improved results in terms of blood loss (MD = 53.67, 95% CI 10.67 to 96.67, p = 0.01), time to first flatus (MD = 21.11, 95% CI 14.99 to 27.23, p < 0.00001), postoperative pain score, and overall hospital stay (MD = 3.47, 95% CI 2.12 to 4.82, p < 0.00001). There was no difference as concerns post-operative mortality, morbidity (OR = 1.55, 95% CI 0.89 to 2.7, p = 0.12), wound infection (OR = 1.69, 95% CI 0.60 to 4.76, p = 0.32), operative time (MD = − 16.10, 95% CI [− 36.57 to 4.36], p = 0.12), harvested lymph nodes (MD = 0.59, 95% CI − 0.18 to 1.36, p = 0.13), and recurrence (OR = 0.97, 95% CI 0.30 to 3.15, p = 0.96).

Conclusions

HALS is an efficient alternative to OS in right colectomy which combines the advantages of OS with the mini-invasive surgery.

Retroileal anastomosis in hand-assisted laparoscopic left colectomy: experience at a single institution

BACKGROUND

Left hemicolectomy and complicated sigmoid colectomy require an anastomosis between the transverse colon and rectum. Generous mobilization will typically allow the colon to reach to the rectum. However, despite full mobilization of the splenic flexure and extensive work on the mesentery, there are cases in which reach to the pelvis is still an issue. Retroileal routing of the colon is one technique for overcoming such a reach problem and achieving a tension-free anastomosis. Performing retroileal routing using laparoscopic techniques has been reported rarely, and to date, there are no data on this technique when performed in a hand-assisted laparoscopic fashion. This study aimed to describe the feasibility of doing a retroileal routing using a hand-assisted laparoscopic technique.

METHODS

This was a retrospective chart review of patients who underwent a colon or rectal resection, either open or laparoscopic, with a pelvic anastomosis, by a single colorectal surgeon at an academic institution between 2008 and 2015 with a focus on the immediate and long-term postoperative complications, estimated blood loss, and operating room time for patients having an operation that included retroileal routing for construction of a colorectal anastomosis.

RESULTS

A total of 340 patients fit inclusion criteria and of these, 13 underwent hand-assisted laparoscopic procedures with retroileal routing of the proximal colon to the colorectal anastomosis. Postoperative morbidity included intubation for CO₂ retention in one patient and a RLL effusion in another patient; there were no anastomotic leaks. Long-term morbidities included two ventral hernias at 2 years postoperatively. Mean operating room time was 208 min. There were no 30- or 90-day mortalities.

CONCLUSIONS

Hand-assisted laparoscopic retroileal routing is a feasible and safe technique in accomplishing a tension-free colorectal anastomosis when proximal colon length makes standard routing of the colon to the rectum an issue.

Long-term results of hand-assisted laparoscopic gastrectomy for advanced Siewert type II and type III esophagogastric junction adenocarcinoma

BACKGROUND

Hand-assisted laparoscopic surgery (HALS) combines laparoscopic surgery with the tactile feedback of a hand-assist device for complex laparoscopic operations. This study aimed to comparatively evaluate the long-term outcomes of patients who underwent HALS versus open surgery for the treatment of advanced Siewert type II and type III adenocarcinoma of the esophagogastric junction (AEG).

METHODS

A retrospective analysis of 77 patients with advanced Siewert type II and IIIAEG between March 2010 and March 2011. Data concerning the basic characteristics of patients, pathological staging, early postoperative course, and long-term follow-up were collected and analyzed.

RESULTS

HALS resulted in significantly lower mean blood loss and mean postoperative hospital stay in comparison to open surgery (P = 0.007 and 0.01, respectively). The mean number of resected lymph nodes was 23.22 ± 9.36 in the HALS group, which was more than in the open surgery group (18.61 ± 6.91, P = 0.015). The cumulative 5-year overall survival (OS) rate was 52.8% (95% CI 43.07-60.09) for all patients in the HALS group (78.6% for stage II patients and 36.4% for stage III patients). The 5-year OS rate was not significantly different between both groups.

CONCLUSIONS

While achieving similar oncological outcomes to open surgery, the HALS approach resulted in reduced blood loss, shortened postoperative hospital stay, and the resection of more lymph nodes. This analysis suggests that HALS may serve as a less invasive and as successful alternative to open surgery for the treatment of advanced Siewert type II and type IIIAEG.

Effects of transcranial direct-current stimulation on laparoscopic surgical skill acquisition

Background

Changes in medical education may limit opportunities for trainees to gain proficiency in surgical skills. Transcranial direct-current stimulation (tDCS) can augment motor skill learning and may enhance surgical procedural skill acquisition. The aim of this study was to determine the effects of tDCS on simulation-based laparoscopic surgical skill acquisition.

Methods

In this double-blind, sham-controlled randomized trial, participants were randomized to receive 20 min of anodal tDCS or sham stimulation over the dominant primary motor cortex, concurrent with Fundamentals of Laparoscopic Surgery simulation-based training. Primary outcomes of laparoscopic pattern-cutting and peg transfer tasks were scored at baseline, during repeated performance over 1 h, and again at 6 weeks. Intent-to-treat analysis examined the effects of treatment group on skill acquisition and retention.

Results

Of 40 participants, those receiving tDCS achieved higher mean(s.d.) final pattern-cutting scores than participants in the sham group (207·6(30·0) versus 186·0(32·7) respectively; P = 0·022). Scores were unchanged at 6 weeks. Effects on peg transfer scores were not significantly different (210·2(23·5) in the tDCS group versus 201·7(18·1) in the sham group; P = 0·111); the proportion achieving predetermined proficiency levels was higher for tDCS than for sham stimulation. Procedures were well tolerated with no serious adverse events and no decreases in motor measures.

Conclusion

The addition of tDCS to laparoscopic surgical training may enhance skill acquisition. Trials of additional skills and translation to non-simulated performance are required to determine the potential value in medical education and impact on patient outcomes. Registration number: NCT02756052 (https://clinicaltrials.gov/).

Hand-assisted laparoscopic surgery versus conventional open surgery in intraoperative and postoperative outcomes for colorectal cancer: An updated systematic review and meta-analysis

AIM

This meta-analysis aims to compare hand-assisted laparoscopic surgery (HALS) and conventional open surgery (OS) for colorectal cancer (CRC) in terms of intraoperative and postoperative outcomes, and to explore the safety, feasibility of HALS for CRC surgery.

METHODS

A systematic literature search with no limits was performed in PubMed, Embase, and Medline. The last search was performed on April 23, 2017. The outcomes of interests included intraoperative outcomes (operative time, blood loss, length of incision, transfusion, and lymph nodes harvested), postoperative outcomes (length of hospital stay, length of postoperative hospital stay, time to first flatus, time to first liquid diet, time to first soft diet, time to first bowel movement, postoperative complications, reoperation, ileus, anastomotic leakage, wound infection, urinary complication, pulmonary infection, and mortality).

RESULTS

Fifteen articles published between 2007 and 2017 with a total of 1962 patients with CRC were included in our meta-analysis. HALS was associated with longer operative time, less blood loss, smaller length of incision, shorter hospital days and postoperative hospital days, less time to first flatus, less wound infection, and less postoperative complications. There was no difference in blood transfusion, lymph node harvested, time to first liquid or soft diet, time to first bowel movement, reoperation, ileus, anastomotic leakage, pulmonary infection, urinary complications, or mortality.

CONCLUSIONS

Our meta-analysis suggests that HALS in CRC surgery improves cosmesis and results in better postoperative recovery outcomes by reducing postoperative complications and hospital days. Furthermore, a large randomized control study is warranted to compare the short-term and long-term outcomes of those 2 techniques for CRC treatment.

Hand-Assisted Laparoscopic Versus Standard Laparoscopic Colectomy: Are Outcomes and Operative Time Different?

BACKGROUND

HAL colectomy is a technique perceived to provide the benefits of laparoscopic surgery while improving tactile feedback and operative time. Published data are largely limited to small, single-institution studies.

METHODS

The 2012-2013 National Surgical Quality Improvement Program Participant Data Use File was queried for patients undergoing elective SL or HAL colectomy. Patients underwent 1:1 propensity matching and had outcomes compared. An additional subgroup analysis was performed for patients undergoing segmental resections only.

RESULTS

13,949 patients were identified, of whom 6084 (43.6 %) underwent HAL colectomy. Patients undergoing HAL versus SL colectomy had higher rates of postoperative ileus (8.7 vs. 6.3 %, p < 0.001), wound complication (8.8 vs. 6.8 %, p = 0.006), and 30-day readmission (7.5 vs. 6.0 %, p = 0.002), without any differences in operative time (156 vs. 157 min, p = 0.713). Amongst segmental colectomies, HAL remained associated with higher rates of wound complications (8.6 vs. 6.5 %, p = 0.016), postoperative ileus (8.9 vs. 6.3 %, p < 0.001), and 30-day readmission (7.1 vs. 5.9 %, p = 0.041) with no difference in operative time between HAL and SL (145 vs. 145 min, p = 0.334).

CONCLUSIONS

Use of HAL colectomy is associated with increased risk of wound complications, postoperative ileus, and readmissions. Importantly, this technique is not associated with any decrease in operative time.

Intraoperative modifiable risk factors of colorectal anastomotic leakage: Why surgeons and anesthesiologists should act together

BACKGROUND

Colorectal anastomotic leakage (CAL) is a major surgical complication in intestinal surgery. Despite many optimizations in patient care, the incidence of CAL is stable (3-19%) [1]. Previous research mainly focused on determining patient and surgery related risk factors. Intraoperative non-surgery related risk factors for anastomotic healing also contribute to surgical outcome. This review offers an overview of potential modifiable risk factors that may play a role during the operation.

METHODS

Two independent literature searches were performed using EMBASE, Pubmed and Cochrane databases. Both clinical and experimental studies published in English from 1985 to August 2015 were included. The main outcome measure was the risk of anastomotic leakage and other postoperative complications during colorectal surgery. Determined risk factors of CAL were stated as strong evidence (level I and II high quality studies), and potential risk factors as either moderate evidence (experimental studies level III), or weak evidence (level IV or V studies).

RESULTS

The final analysis included 117 articles. Independent factors of CAL are diabetes mellitus, hyperglycemia and a high HbA1c, anemia, blood loss, blood transfusions, prolonged operating time, intraoperative events and contamination and a lack of antibiotics. Unequivocal are data on blood pressure, the use of inotropes/vasopressors, oxygen suppletion, type of analgesia and goal directed fluid therapy. No studies could be found identifying the impact of body core temperature or mean arterial pressure on CAL. Subjective factors such as the surgeons' own assessment of local perfusion and visibility of the operating field have not been the subject of relevant studies for occurrence in patients with CAL.

CONCLUSION

Both surgery related and non-surgery related risk factors that can be modified must be identified to improve colorectal care. Surgeons and anesthesiologists should cooperate on these items in their continuous effort to reduce the number of CAL. A registration study determining individual intraoperative risk factors of CAL is currently performed as a multicenter cohort study in the Netherlands.

Future of Minimally Invasive Colorectal Surgery

Minimally invasive surgery is slowly taking over as the preferred operative approach for colorectal diseases. However, many of the procedures remain technically difficult. This article will give an overview of the state of minimally invasive surgery and the many advances that have been made over the last two decades. Specifically, we discuss the introduction of the robotic platform and some of its benefits and limitations. We also describe some newer techniques related to robotics.

Hand-assisted laparoscopic vs open colectomy: an assessment from the American College of Surgeons National Surgical Quality Improvement Program procedure-targeted cohort

BACKGROUND

Perioperative outcomes of patients who underwent hand-assisted colorectal laparoscopic (HALS) vs open colectomy were compared using recently released procedure-targeted database.

METHODS

Review was conducted using the 2012 colectomy-targeted American College of Surgeons National Surgical Quality Improvement Program database. Patients were classified into 2 groups according to final surgical approach: HALS vs open (planned). Groups were matched (1:1) based on age, gender, body mass index, surgical procedure, diagnosis, American Society of Anesthesiologists score, and wound classification. Multivariate logistic regression analysis was conducted for group comparison.

RESULTS

Of 7,303 patients, 1,740 patients were matched in each group. Open group had higher proportion of patients with preoperative dyspnea (P = .01), ascites (P = .01), weight loss (P < .001), smoking history (P = .04), and increased work relative value units (P < .001). After adjusting for difference in baseline comorbidities, overall morbidity, superficial, deep, and organ-space surgical site infection, urinary tract infection, ileus, reoperation, readmission, and hospital stay were significantly higher in open group (P < .05).

CONCLUSIONS

National Surgical Quality Improvement Program targeted-data demonstrated several advantages of HALS compared with open colonic resection including shorter hospital stay and lower complication rate. Further adoption of HALS technique as a bridge to straight laparoscopy or tool in difficult cases can positively impact the short-term outcomes after colectomy when compared with open technique.

Laparoscopic colorectal surgery: Current status and implementation of the latest technological innovations

The introduction of laparoscopy is an example of surgical innovation with a rapid implementation in many areas of surgery. A large number of controlled studies and meta-analyses have shown that laparoscopic colorectal surgery is associated with the same benefits than other minimally invasive procedures, including lesser pain, earlier recovery of bowel transit and shorter hospital stay. On the other hand, despite initial concerns about oncological safety, well-designed prospective randomized multicentre trials have demonstrated that oncological outcomes of laparoscopy and open surgery are similar. Although the use of laparoscopy in colorectal surgery has increased in recent years, the percentages of patients treated with surgery using minimally invasive techniques are still reduced and there are also substantial differences among centres. It has been argued that the limiting factor for the use of laparoscopic procedures is the number of surgeons with adequate skills to perform a laparoscopic colectomy rather than the tumour of patients’ characteristics. In this regard, future efforts to increase the use of laparoscopic techniques in colorectal surgery will necessarily require more efforts in teaching surgeons. We here present a review of recent controversies of the use of laparoscopy in colorectal surgery, such as in rectal cancer operations, the possibility of reproducing complete mesocolon excision, and the benefits of intra-corporeal anastomosis after right hemicolectomy. We also describe the results of latest innovations such as single incision laparoscopic surgery, robotic surgery and natural orifice transluminal endoscopic surgery for colon and rectal diseases.

Hand-Assisted Laparoscopic Approach in Colon Surgery

BACKGROUND

This study sought to compare outcomes of patients who underwent hand-assisted laparoscopic (HAL) colectomy with open and laparoscopic colectomy (LP).

STUDY DESIGN

The NSQIP databases were used to examine the clinical data of patients who underwent elective colectomy during 2012-2013. Multivariate regression analysis was performed to compare the three surgical approaches.

RESULTS

We sampled a total of 21,090 patients who underwent colectomy. Of these, 7480 (35.5 %) had open colectomy (OC), 8751 (41.5 %) had a laparoscopic colectomy, 2860 (13.6 %) had a HAL colectomy, and 1999 (9.5 %) had an open procedure converted from LC or HAL. Multivariate regression analysis revealed HAL colectomy had a similar mortality (AOR 0.53, P = 0.07) and a lower morbidity (AOR 0.37, P < 0.01) compared to OC. LC had lower mortality (AOR 0.58, P = 0.02) and morbidity (AOR 0.43, P < 0.01) compared to OC. Mortality of patients who underwent HAL was not significantly different from LC (AOR 0.90, P = 0.79); however, morbidity of such patients was significantly higher than for patients who underwent LC (AOR 1.29, P < 0.01).

CONCLUSIONS

HAL colectomy is a safe approach with significant advantages compared to open colectomy. Although the morbidity of patients who underwent HAL is higher than patients who underwent LC, the morbidity rate is still lower than OC.

Hand-Assisted Laparoscopic Approach in Colon Surgery

BACKGROUND

This study sought to compare outcomes of patients who underwent hand-assisted laparoscopic (HAL) colectomy with open and laparoscopic colectomy (LP).

STUDY DESIGN

The NSQIP databases were used to examine the clinical data of patients who underwent elective colectomy during 2012-2013. Multivariate regression analysis was performed to compare the three surgical approaches.

RESULTS

We sampled a total of 21,090 patients who underwent colectomy. Of these, 7480 (35.5 %) had open colectomy (OC), 8751 (41.5 %) had a laparoscopic colectomy, 2860 (13.6 %) had a HAL colectomy, and 1999 (9.5 %) had an open procedure converted from LC or HAL. Multivariate regression analysis revealed HAL colectomy had a similar mortality (AOR 0.53, P = 0.07) and a lower morbidity (AOR 0.37, P < 0.01) compared to OC. LC had lower mortality (AOR 0.58, P = 0.02) and morbidity (AOR 0.43, P < 0.01) compared to OC. Mortality of patients who underwent HAL was not significantly different from LC (AOR 0.90, P = 0.79); however, morbidity of such patients was significantly higher than for patients who underwent LC (AOR 1.29, P < 0.01).

CONCLUSIONS

HAL colectomy is a safe approach with significant advantages compared to open colectomy. Although the morbidity of patients who underwent HAL is higher than patients who underwent LC, the morbidity rate is still lower than OC.

Adoption of Laparoscopic Colorectal Surgery: It Was Quite a Journey

The adoption of laparoscopic colorectal surgery has been a slow but steady progress. The first adopters rapidly expanded the application of the technology to all colorectal pathology. Issues related to extraction and port site recurrence of cancer delayed widespread adoption until incontrovertible data from well-powered prospective randomized studies confirmed equipoise with open surgery. Since that time, the data has consistently demonstrated patient-care benefits related to reductions in both short- and long-term complications historically associated with open colectomy. The potential for further improvement related to single-port access, robotic assistance, and natural orifice access for both the surgery and/or extraction will await the test of time. However, it is clear now that laparoscopic colorectal surgery is the new standard of care and a key enabler of enhanced recovery programs.

Hand-assisted laparoscopic surgery compared with open resection for mid and low rectal cancer: a case-matched study with long-term follow-up

BACKGROUND

This study was designed to compare the long-term surgical outcomes of patients with mid and low rectal cancer after open or hand-assisted laparoscopic surgery (HALS).

METHODS

A case-matched controlled prospective analysis of 116 patients who underwent hand-assisted laparoscopic surgery (HALS) for stage I to III mid and low rectal cancer from 2005 to 2010 was performed. Contemporary patients who underwent open rectal surgery were matched to the HALS group at the ratio of 1:1. The perioperative clinical outcomes, postoperative pathology, and survival outcomes were compared between the groups.

RESULTS

The patient characteristics between the two groups were comparable. Ninety patients in the open group and 85 in the HALS group received sphincter-preserving surgery. HALS resulted in less blood loss and wound infection, faster return to oral diet, shorter postoperative hospital stay, and longer operating time. The two groups had similar complication rates. Lymph node retrieval and involvement of circumferential and distal margins were similar for both procedures. Cumulative incidences of locoregional recurrence, disease-free, or overall survival rates were statistically similar.

CONCLUSIONS

This study suggests that HALS for mid and low rectal cancer is acceptable in terms of short-term clinical outcomes and long-term survival results.

Comparative Study on Therapeutic Efficacy Between Hand-Assisted Laparoscopic Surgery and Conventional Laparotomy for Acute Obstructive Right-Sided Colon Cancer

INTRODUCTION

This retrospective study aims to compare open colectomy and hand-assisted laparoscopic surgery (HALS) in the management of acute obstructive right-sided colon cancer and to analyze and evaluate the feasibility and safety of HALS.

PATIENTS AND METHODS

Ten consecutive patients who underwent hand-assisted laparoscopic right hemicolectomy due to acute obstructive right-sided colon cancer were retrospectively well matched with 25 patients scheduled for a conventional laparotomy during the same time. Demographic, intraoperative, and postoperative data were assessed.

RESULTS

The HALS group had the advantage in the length of incision (5.8±0.7 cm) over the conventional group (16±2.3 cm) (P<.05), and the mean blood loss during the operations was significantly less in the HALS group (30±15.2 mL) than in the laparotomy group (90±29.4 mL) (P<.05). Moreover, the time of postoperative ambulation was earlier (2.5±0.8 days versus 3.2±0.9 days) (P<.05). Seven cases underwent intestinal decompression for severe intestinal dilatation and had a satisfactory result. The hand-assisted device can fairly meet the demands of a minimally invasive operation and can protect the abdominal incision and avoid infection. There was no intergroup difference in complication rate, although the conventional group had a higher rate.

CONCLUSIONS

In this study, compared with conventional laparotomy for acute obstructive right-sided colon neoplasm, HALS is associated with less blood loss, shorter incision, and earlier ambulation. Emergency laparoscopic-assisted right hemicolectomy can be safely performed in patients with obstructing right-sided colonic carcinoma. If practiced more, it might be advocated as a bridge between the conventional open approach and traditional laparoscopic surgery.

Medical students impact laparoscopic surgery case time

BACKGROUND

Medical students (MS) are increasingly assuming active roles in the operating room. Laparoscopic cases offer unique opportunities for MS participation. The aim of this study was to examine associations between the presence of MS in laparoscopic cases and operation time and postoperative complication rates.

MATERIALS AND METHODS

Data from the American College of Surgeons National Surgical Quality Improvement Program were linked to operative records for nonemergent, inpatient, and laparoscopic general surgery cases at our institution from January, 2009-January, 2013. Cases were grouped into eight distinct procedure categories. Hospital records provided information on the presence of MS. Demographics, comorbidities, intraoperative variables, and postoperative complication rates were analyzed.

RESULTS

Seven hundred laparoscopic cases were included. Controlling for wound class, procedure group, and surgeon, MS were associated with an additional 28 min of total operative time. The most significant increase occurred between the skin incision and skin closure. No significant association between the presence of MS and postoperative complications was observed.

CONCLUSIONS

This is the first retrospective analysis to examine the effect of MS presence during laparoscopic procedures. Increase in the operation time associated with the presence of MS should be examined further, to optimize the educational experience without incurring increased cost due to increased operation time.