Surgical Endoscopy

, Volume 21, Issue 10, pp 1800–1805

Robot-assisted versus conventional laparoscopic fundoplication: short-term outcome of a pilot randomized controlled trial

  • B. P. Müller-Stich
  • M. A. Reiter
  • M. N. Wente
  • V. V. Bintintan
  • J. Köninger
  • M. W. Büchler
  • C. N. Gutt

DOI: 10.1007/s00464-007-9268-y

Cite this article as:
Müller-Stich, B.P., Reiter, M.A., Wente, M.N. et al. Surg Endosc (2007) 21: 1800. doi:10.1007/s00464-007-9268-y



Robotic technology represents the latest development in minimally-invasive surgery. Nevertheless, robotic-assisted surgery seems to have specific disadvantages such as an increase in costs and prolongation of operative time. A general clinical implementation of the technique would only be justified if a relevant improvement in outcome could be demonstrated. This is also true for laparoscopic fundoplication. The present study was designed to compare robotic-assisted (RALF) and conventional laparoscopic fundoplication (CLF) with the focus on operative time, costs und perioperative outcome.


Forty patients with gastro-esophageal reflux disease were randomized to either RALF by use of the daVinci® Surgical System or CLF. Nissen fundoplication was the standard anti-reflux procedure. Peri-operative data such as length of operative procedure, intra-and postoperative complications, length of hospital stay, overall costs and symptomatic short-term outcome were compared.


The total operative time was shorter for RALF compared to CLF (88 vs. 102 min; p = 0.033) consisting of a longer set-up (23 vs. 20 min; p = 0.050) but a shorter effective operative time (65 vs. 82 min; p = 0.006). Intraoperative complications included one pneumothorax and two technical problems in the RALF group and two bleedings in the CLF group. There were no conversions to an open approach. Mean length of hospital stay (2.8 vs. 3.3 days; p = 0.086) and symptomatic outcome thirty days postoperatively (10% vs. 15% with ongoing PPI therapy; p = 1.0 and 25% vs. 20% with persisting mild dysphagia; p = 1.0) was similar in both groups. Costs were higher for RALF than for CLF (€ 3244 vs. € 2743, p = 0.003).


In comparison with CLF, operative time can be shorter for RALF if performed by an experienced team. However, costs are higher and short-term outcome is similar. Thus, RALF can not be favoured over CLF regarding perioperative outcome.


Robotic surgery Laparoscopic fundoplication Gastroesophageal reflux disease Laparoscopy Randomized controlled trial 

Robotic technology and telemanipulation systems represent the latest developments in minimally-invasive surgery. They offer different technical improvements compared to standard laparoscopy, such as the improved ergonomic position of the surgeon, three-dimensional visualization of the operating field and increased maneuverability of the instruments. These key features might allow complex minimally-invasive procedures to be performed more easily than with conventional laparoscopic surgery. The feasibility of a variety of robotic-assisted surgical procedures such as cholecystectomy [3, 5, 10, 14, 15, 16, 23, 24, 25], colorectal resection [10, 15, 27, 28], adrenalectomy [8], cardiomyotomy [26], fundoplication [1, 3, 5, 10, 11, 20, 25, 29], and even esophagectomy [13] has been demonstrated in the last decade. Nevertheless, robotic-assisted surgery seems to have specific disadvantages such as longer operative time and higher costs [12]. These drawbacks would only be acceptable if some irrefutable advantages could be demonstrated. Experimental studies have shown a benefit for the robotic system regarding speed and precision in performing tasks which require accurate and fine movements in a very limited working space [6, 17]. Thus, surgical procedures which might benefit from the theoretical advantages of robotic assistance could be the fundoplication or other types of anti-reflux surgery because they are performed in the narrow subphrenic space.

Since the introduction of laparoscopic anti-reflux therapy and hiatal hernia repair in the early 1990’s, these procedures have been becoming increasingly popular [7, 9]. However, conventional minimally-invasive surgical procedures are affected by reduced degrees of freedom for individual movements of the instruments. Here, robotic assistance may allow for a distinct improvement.

This article compares the respective perioperative outcomes of robotic- assisted laparoscopic fundoplication (RALF) and conventional laparoscopic fundoplication (CLF), in particular regarding operative time and costs. These objectives represent the secondary endpoints of this pilot randomized controlled trial which was designed in order to obtain estimates for a comparison of symptomatic outcome and quality of life in the mid-term follow-up after twelve months. However, since the perioperative results seemed to be interesting it was decided to outline them in the present work.

Patients and methods

Preoperative assessment

Patients with symptomatic gastro-esophageal reflux disease (GERD) were screened for inclusion and exclusion criteria stated in the study protocol. Inclusion criteria were age over 18 years, history of more than 6 months of symptomatic GERD requiring acid suppressive therapy of a minimal standard dosage of the applied proton pump inhibitor (PPI) for at least 3 months in the preceding year. Exclusion criteria were previous major upper abdominal surgery, hiatal hernias with paraesophageal involvement, obesity with a body mass index of over 40 kg/m² and evidence of primary esophageal disorders such as achalasia, sclerodermia or malignant diseases.

The preoperative assessment consisted of endoscopy, 24-h pH monitoring and barium swallow. Reflux related symptoms were recorded using a modified gastrointestinal symptom rating scale questionnaire (GSRS) [18]. Dysphagia was assessed with a four-step Linkert Scale (1 = none, 2 = mild, 3 = moderate, 4 = severe).

Operative technique

Patients were randomized to either RALF or CLF the day before surgery. Intraoperative randomization was not applicable in the study setup due to technical and logistical reasons. However, none of the patients was aware of the surgical method applied. RALF was performed by a single surgeon after having passed a learning phase of 30 procedures. CLF was performed by three different surgeons including the one responsible for RALF, all highly experienced in laparoscopy; with at least 30 CLF procedures performed before.

For the surgical procedure, patients from both groups were positioned in combined French and reversed Trendelenburg position. The standard setting for CLF was with the surgeon standing between the patient’s legs, the first assistant positioned to the patient’s right, and the laparoscopic tower being placed at the cranial extremity of the patient. For RALF the daVinci® Surgical System (Intuitive Surgical, Mountain View, California, USA) was used; the movable robotic module with its three robotic arms was positioned directly cranial to the patient’s head. The surgeon, sitting at the master console aside the operating table, steered the actuator arms of the robot while the first assistant stood to the patient’s left, watching the procedure on a conventional monitor. He assisted by exchanging robotic instruments, adjusting the settings of the machine or employing conventional laparoscopic instruments (Fig. 1).
Fig. 1.

Positioning of the telemanipulator system for robotic-assisted laparoscopic fundoplication.

After creating a pneumoperitoneum of 12 mmHg using the Veress needle all trocars were placed in standardized positions. For RALF a 12-mm trocar for the 30° angled dual scope and two 7-mm robotic trocars for robotic instruments were used. A 10 mm accessory trocar was intended for assistance, for example by clipping, suction and using conventional laparoscopic instruments. Similar standard trocars, only differing in two 5-mm instead of 7-mm trocars for standard laparoscopic instruments and an equally angled scope were used for CLF. In both groups a rigid 5mm Nathanson liver retractor (Mediflex®, Surgical Instruments, Islandia, New York, USA) was used for adequate exposition of the esophageal hiatus through an additional subxiphoidal incision (Fig. 2). Operative steps were similar in both groups. With a 32-F orogastric tube in place the mobilization of the esophagus started after incision of the lesser omentum, close to the right pillar and continued on the anterior part of the phrenoesophageal membrane. Phrenoesophageal attachments to the right and left diaphragmatic pillars were completely dissected. To facilitate this procedure a band was placed around the lower esophagus and used for adequate positioning of the esophagus. Then the dissection was extended into the lower mediastine for complete mobilization of the distal esophagus. Short gastric vessels were not divided. The hiatus was narrowed by a various number of non-resorbable sutures, depending on the enlargement. Finally a “short and floppy” Nissen fundoplication was performed with three interrupted sutures, the middle one being anchored to the anterior esophageal wall to prevent displacement of the wrap.
Fig. 2.

Trocar positions for both robotic-assisted and conventional fundoplication: (1) optic trocar; (2 and 3) working trocars; (4) accessory trocar; (5) liver retractor.

Perioperative assessment

A set of perioperative data was analyzed including operative time, perioperative complications, length of hospital stay, costs and symptomatic outcome. Operative time was analyzed in total and specified in set-up time and effective operative time. Set-up time was defined as the time frame between the patient’s access to the operating room and the introduction of the first laparoscopic instrument into the abdominal cavity. Effective operative time was recorded from the introduction of the first laparoscopic instrument until the completion of the last skin suture. Intraoperative incidents were categorized as either surgical, anesthesiological or technical, depending on the type of complication. Postoperative complications (medical and surgical), length of hospital stay and symptomatic outcome according to the GSRS were documented at discharge and thirty days postoperatively. Costs included the expenses for staff and the use of the operating room, as well as the costs for surgical devices (disposable and reusable instruments, covers and trocars) and the length of hospital stay. Initial costs for the purchase of the robot or the laparoscopy tower were not included in the calculation.

Mid-term follow-up after twelve months will include the assessment of the patients’ symptomatic outcome and quality of life using the GSRS and quality of life in reflux and dyspepsia questionnaire, respectively. To avoid assessment bias and assure validity of these primary outcome parameters the patients’ and assessor’s blinding was not broken for the present short-term analysis. Furthermore, a final endoscopy is planned in order to objectify the operative outcome regarding reflux lesions and hiatal hernias. However, since this follow-up had not been completed at time of writing, these results will not be outlined in the present publication.

The study protocol was approved by the institutional ethics committee and informed consent was obtained from every patient.

Statistical analysis

This pilot randomized controlled trial was conducted with the aim of generating estimates for the sample size calculation of a future multicenter randomized controlled trial in which symptomatic outcome and quality of life in the mid-term follow-up are planned to be the primary endpoints. Perioperative outcome and costs which are reported in the present paper represent secondary endpoints of the study. Therefore, no power calculation was performed so far.

Continuous variables were compared using the Student’s t test or the Mann-Whitney U test, depending on the data’s distribution. Categorical data was compared by use of the chi-squared test and the two tailed Fisher´s exact test as appropriate. A two-sided p-value <0.05 was considered as statistically significant. All calculations were conducted using SPSS® Version 10.0 (SPSS, Chicago, Illinois, USA).


Between August, 2004 and December 2005, 52 patients were screened according to inclusion and exclusion criteria. Twelve patients could not be enrolled for having a body mass index exceeding 40 kg/m² (one patient) and for protocol refusal (eleven patients). Forty patients were enrolled. The preoperative patients´ characteristics are displayed in Table 1.
Table 1.

Patient characteristics





N (female/male)




Age (yr)

49.6 ± 12.0 (23–71)

50.5 ± 12.4 (25–75)


Body Mass Index (kg/m2)

29.2 ± 5.83 (21–40)

26.2 ± 3.4 (19–31)



Los Angeles A




Los Angeles B




Los Angeles C




Los Angeles D




GSRS (reflux syndrome)

4.0 ± 1.7 (2–7)

4.4 ± 1.5 (2–7)


Values are mean ± standard deviation (range). RALF = robot-assisted laparoscopic fundoplication; CLF = conventional laparoscopic fundoplication; GSRS = gastrointestinal symptom rating scale

* Chi square test; Student’s t test

The total operative time was found to be significantly shorter for the RALF group compared to the CLF group, consisting of a trend towards a longer set-up time but a significantly shorter effective operative time (Table 2). Except for two cases of bleedings in the CLF group and one pneumothorax in the RALF group, no other intraoperative surgical complications were encountered. Two minor technical incidents occurred in the RALF group: one failure of the optical system during set-up, which was corrected within 20 minutes, and one breakdown of a robotic instrument that was easily resolved by replacement. All these intraoperative incidents caused a prolongation of operative time explaining the wide range with a maximum of 130 minutes. However, there were neither conversions nor re-operations in either of the groups.
Table 2.

Operative times (in min)




p value*

Total operative time

88 ± 18 (60–150)

102 ± 19 (75–152)


Set up time

23 ± 5 (14–35)

20 ± 3 (15–30)


Effective operative time

65 ± 18 (40–130)

82 ± 18 (55–130)


Values are mean ± standard deviation (range). RALF = robot-assisted laparoscopic fundoplication; CLF = conventional laparoscopic fundoplication

* Student’s t test

Major postoperative complications did not occur in any of the groups. Mild postoperative dysphagia recorded at discharge was present in 16 (80%) patients in the RALF group and 18 (90%) patients in the CLF group (p = 1.0). Continuous postoperative dysphagia, still present thirty days postoperatively, was reported by nine patients, five (25%) in the RALF group and four (20%) in the CLF group (p = 1.0). The respective mean dysphagia scores were 1.3 ± 0.6 and 1.3 ± 0.7 (p = 0.809). No endoscopic dilatation procedure was necessary in these patients. Thirty days postoperatively two (70%) patients undergoing RALF and three (15%) patients from the CLF group resumed PPI therapy due to at least mild reflux symptoms (p = 1.0). Patients from the RALF group had a mean reflux score of 1.3 ± 0.7 while CLF patients scored 1.6 ± 1.3 (p = 0.064).

Mean length of hospital stay was 2.9 ± 0.8 days for the RALF group and 3.3 ± 0.8 days for the CLF group (p = 0.086). Costs for RALF were significantly higher than for CLF, although initial and annual expenses for the telemanipulator system were not included in the calculation (Table 3).
Table 3.

Operation costs (in €)




p value*

Total operative costsa

1534 ± 111 (1363–1896)

763 ± 115 (603–1059)


Length of hospital stay

1710 ± 488 (600–2400)

1980 ± 481 (1200–3000)


Total costs

3244 ± 512 (1511–3970)

2743 ± 483 (1892–3763)


Values are mean ± standard deviation (range). RALF = robot-assisted laparoscopic fundoplication; CLF = conventional laparoscopic fundoplication

* Student’s t test

a Total operative costs include personnel, sterilization of reusable instruments, and disposable instruments


In the last decade, a variety of robotic-assisted surgical procedures including fundoplication have been proven to be feasible and safe. Many of these retrospective analyses showed that, apart from being more expensive, robotic-assisted surgery needed longer operative time due to both extensive set-up time and prolonged duration of the operative procedure. However, scientific evidence is limited to one prospective non-randomized and three randomized controlled trials.

In a prospective non-randomized trial Melvin et al. compared twenty RALF to twenty CLF. In this trial significantly longer operative times were reported for RALF compared to CLF (141 vs. 97 min). Postoperative complications and length of hospital stay were similar in both groups. This study was the only one, so far, highlighting a significant difference in short-term functional results between RALF and CLF. The number of patients resuming PPI therapy during a follow-up period of seven months was none in the RALF group and six patients in the CLF group [19].

Cadière et al. reported in a randomized trial comparing ten RALF to eleven CLF significantly increased operative time for RALF (76 vs. 52 min), besides similar postoperative complications and perioperative outcome. Median length of hospital stay was one day in each group, with a range from one to four days for RALF and 1 one to 18 days for CLF. No functional results were recorded [4].

In accordance with the latter, Morino et al. showed in a randomized comparison of 25 RALF with 25 CLF significantly increased operative times for RALF (131 vs. 91 min), but no differences in complications, length of hospital stay or postoperative short-term outcome. Additionally, this was the first controlled trial dealing with costs. It reported significantly higher costs for RALF compared to the CLF group (€ 3157 vs. € 2 1527) [21].

Similar results were published in a randomized but non-blinded trial by Nakadi et al. including a total of 20 patients with a significantly longer operative time (137 vs. 96 5 min), equal length of hospital stay, complications and perioperative outcome. During a follow-up period of twelve months the functional outcome and postoperative complications were similar except for a significantly higher rate of complications for the RALF group three months postoperatively. In addition, higher costs were reported 9 for the RALF compared to the CLF group (€ 6973 vs. € 5167) [22].

In summary, the existing comparative studies consistently indicate increased operative times, higher costs and similar short-term outcome for RALF. Only one prospective, non-randomized trial could show a possible advantage over standard laparoscopy in better functional results after 3 months.

Our study indicates for the first time that RALF can be performed in a significantly shorter operative time (88 vs. 102 min) compared to CLF, despite a marginally increased set-up time. Regarding complications and short-term outcome we were not able to find any differences corroborating the results of the earlier trials.

The main reason for the particular results regarding effective operative time was most probably the fact that one single surgeon, highly experienced in robotic surgery, was responsible for all RALF procedures. This setting indicates that RALF can be done faster due to the special features offered by the robotic system, especially if applied by a well-trained surgical team. In particular, the mobilization of the hiatus and suturing of the gastric wrap in a narrow space can greatly be facilitated by the excellent and intuitive maneuverability of the instruments.

Additionally, our results indicate that the set-up time for RALF can be approximated to those for CLF by a consistent team, made up of specialized and experienced personnel. The creation of a surgical infrastructure supporting the regular use of an admittedly immobile and heavy telemanipulation-system may even further shorten the set-up time.

Nevertheless, one specific disadvantage of the daVinci® Surgical System persisted in our study: higher operative costs even if high purchase and maintenance costs due to expensive semi-disposable instruments, which can only be used for a predefined number of procedures, are not considered. Taking into account that this trial did not show any effects of RALF on postoperative short-term outcome, shorter operative time itself is not really a justification for the higher operative costs.

Nevertheless, given a surgeon well-trained in robotic surgery and a team, experienced in handling the daVinci Surgical System, the system offers significant advantages in terms of intraoperative maneuverability and handling. Under such circumstances complex surgical procedures may be performed more easily and more accurately compared to conventional endoscopic surgery. This might lead to better outcome with better functional results and fewer recurrences in the long-term follow-up. However, this has to be proven in further trials with longer follow-up periods.

Another potential justification for the higher costs might be the improved ergonomics for the surgeon. There is a comparative study by Berguer and Smith conducted with 10 volunteer surgeons performing two different tasks in a laparoscopic trainer using conventional and robotic assisted technique. The results suggested that robotic assisted procedures were less stressful indicated by a decreased skin conductance and lower thumb electromyographic signals. However, the authors were not able to prove this hypothesis due to a too small sample size and probably a too short duration of the tasks tested [2]. Further investigations are needed in this direction since surgeons might benefit from improved ergonomics in regard of musculoskeletal impairments after a whole professional life as endoscopic surgeon.

Admittedly, the present pilot randomized controlled trial was not designed to compare short-term outcome of RALF and CLF as the primary endpoint. However, since the short-term results were surprising with respect to operative time on the one hand and corroborated the existing evidence regarding operative costs and perioperative outcome on the other, it was decided that an undelayed publication of these results would be of interest. With intent to guarantee an accurate and valid assessment of the primary endpoint after twelve months the maintenance of the patients’ and the assessor’s blinding was self-evident.

In summary, besides a shortened operative time, the present pilot trial did not reveal a further benefit of the robotic assistance for laparoscopic fundoplication. Further trials that focus on long-term outcome are needed to find a potential advantage justifying the higher costs for RALF. In this regard we are awaiting the final results of the present trial considering symptomatic outcome and quality of life after the scheduled twelve months follow-up.


The present study was conducted within the setting of the “Research training group 1126: Intelligent Surgery -Development of new computer-based methods for the future workplace in surgery” founded by the German Research Foundation.

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • B. P. Müller-Stich
    • 1
  • M. A. Reiter
    • 1
  • M. N. Wente
    • 1
  • V. V. Bintintan
    • 2
  • J. Köninger
    • 1
  • M. W. Büchler
    • 1
  • C. N. Gutt
    • 1
  1. 1.Department of SurgeryUniversity of HeidelbergHeidelbergGermany
  2. 2.Department of Surgery, 1st Surgical Clinic, “Iuliu Hatieganu,”University of Medicine and PharmacyCluj-NapocaRomania

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