Visual analog scale (VAS) scores for patients undergoing laparoscopic and open repairs on postoperative days (PODs) 1 (A) and 7 (B).
Visual analog scale (VAS) scores on postoperative day 1 by patient age.
Fujita F, Lahmann B, Otsuka K, Lyass S, Hiatt JR, Phillips EH. Quantification of Pain and Satisfaction Following Laparoscopic and Open Hernia Repair. Arch Surg. 2004;139(6):596-600. doi:10.1001/archsurg.139.6.596
Subjective experiences can be quantified by visual analog scale (VAS) scoring to improve comparison of surgical techniques.
Prospective collection of outcome data by interview of patients at 1 day and 1 week following nonrandomized elective hernia repair by a single surgical group between May 1998 and April 2003.
Cedars-Sinai Medical Center, Los Angeles, Calif.
A total of 253 patients (239 men; mean age, 59 years) underwent repair by laparoscopic (n = 110, 105 bilateral, 92 total extraperitoneal, and 18 transabdominal preperitoneal) or tension-free open (n = 143, 133 unilateral) approach. Laparoscopic patients were significantly younger (52.0 vs 63.8 years, P<.001).
Main Outcome Measures
Subjective measures included VAS scores (1-10, 1 indicates best) for pain at 1 day and 1 week postoperatively and overall satisfaction at 1 week. Objective measures included quantity and days of analgesic use and days before return to regular activities, including work and driving. Results were also compared by patient age (Spearman analysis).
Satisfaction was high for both procedures; the laparoscopic procedure was superior only for return to work and driving. Spearman analysis showed a significant inverse relation between age and first-day pain (r= −0.15, P= .01), independent of operative approach. Because laparoscopic patients were younger, patients younger than 65 years were analyzed separately; laparoscopic patients had significantly less first-day pain (5.44 vs 6.30, P= .02).
Pain following hernia repair was age dependent. Following laparoscopic repair, patients had lower first-day pain scores in younger patients and earlier return to normal activities in all patients. Satisfaction was similar for both approaches. Subjective experiences can be quantified, compared to detect subtle differences in outcome for competing surgical techniques, and used to counsel patients before operation, with the goal of improving satisfaction.
Surgery has been transformed in the last decade not only by technology but also by efforts to make surgical decision making evidence based. Sophisticated outcome measures are designed to help patients and payers discriminate among procedures, practitioners, and hospitals. Crude measures, including 30-day morbidity and mortality, no longer are sufficient; patients demand quality-of-life measures, whereas payers expect satisfaction data as well. These changes preceded but were accelerated by the laparoscopic revolution, which promised less pain, improved cosmesis, and shorter disability, often without compelling randomized trials.
Outcome measures are particularly important for common procedures, such as herniorrhaphy. In inguinal herniorrhaphy, major complications and mortality are so infrequent that most studies cannot attain sufficient power to discern among treatment groups. Since the widespread adoption of mesh in primary hernia repair, recurrence has decreased from approximately 10% to approximately 1%. This has been documented by evidence-based studies that show a significant reduction in recurrence without an increase in complications, infection, pain, or disability.1 Pain has been quantified by a variety of instruments, including verbal rating scales, plain numerical scales, and the visual analog scale (VAS). Our VAS uses various expressive faces to quantify pain and has been shown to be a reliable and linear tool for assessing mild-to-severe postoperative pain.2- 4
The present study was undertaken to test the hypothesis that VAS scoring can be used to quantify patients' subjective experiences of pain and satisfaction. Such quantification may help to identify small differences among competing operative techniques.
All patients undergoing elective mesh groin hernia repair by a single surgical group at Cedars-Sinai Medical Center, Los Angeles, Calif, between May 1998 and April 2003 were entered into this study. The type of repair was chosen by the surgeon in consultation with the patient. Open repair with the patient under local anesthesia was recommended for unilateral hernias and for patients at increased risk of complications while under general anesthesia. Patients with bilateral or recurrent hernias were offered laparoscopic repair, unless there was a giant scrotal hernia or a history of extensive lower abdominal or preperitoneal operation. Laparoscopic repair was also performed in good-risk patients with unilateral hernias who requested this approach. Open repair was performed using tension-free Lichtenstein5 or mesh plug6 techniques. Laparoscopic repair was performed using predominantly the total extraperitoneal or occasionally transabdominal preperitoneal approaches.7,8
Data were compiled concurrently for each patient and included age, sex, unilateral vs bilateral hernia, operative approach, operative time, and complications. All patients were seen on the seventh postoperative day, at which time they completed an individual questionnaire administered by the operating surgeon. Subjective and objective data were collected from this questionnaire.
Subjective data included satisfaction and pain. Patients were asked to rate (1) overall satisfaction with the operative experience on the seventh postoperative day and (2) postoperative pain on the first and seventh days. The rating tool was a VAS score with a range of 1 (best score) to 10 (worst score)2- 4; patients were asked to identify the facial expression that represented their subjective experience (Figure 1), and the corresponding number was then recorded.
Objective data included (1) quantity and duration of analgesic use and (2) the number of postoperative days before returning to regular activities in which the patients had engaged before operation. These activities included driving, work, and athletics; patients were instructed to return to these activities when they felt comfortable doing so. They were instructed not to drive or operate machinery while they were taking narcotic pain medication.
Analyses were performed using GraphPad Prism version 3.02 (GraphPad Software Inc, San Diego, Calif). Continuous variables were compared with the 2-tailed, paired t test, and categorical variables were compared with Fisher exact test or χ2 analysis. Spearman rank order correlation was used to analyze a relationship between postoperative pain and age. Statistical significance was accepted at the .05 level.
During the study period, 300 patients underwent inguinal herniorrhaphy with mesh. Of these, 47 were excluded because of incomplete questionnaires. Consequently, 253 patients, 110 who underwent laparoscopic repair and 143 who underwent open repair, were compared in this analysis. Average age was 58.6 years (range, 20-98 years), and 239 (95%) were male. The demographics of the 47 excluded patients were similar to those included in the study.
Patients undergoing laparoscopic repair were younger and more frequently male. Bilateral hernias were far more common in the laparoscopic group. All laparoscopic repairs required general anesthesia, whereas most open repairs were performed with the patient under local anesthesia. The principal operative technique was total extraperitoneal repair in the laparoscopic group and Lichtenstein repair in the open group. Operative times were significantly longer for laparoscopic repairs (Table 1).
There were no major complications. Although the difference did not achieve significance, minor complications were more common in the laparoscopic group and included wound problems in 10 (infection, hematoma, or seroma), urinary retention in 4, and others (non–hernia-related complaints, such as dizziness, hemorrhoids, and constipation) in 5. Complications in the open repair group included wound problems in 12 and urinary retention in 1.
Data regarding postoperative hospital admission were available for 223 of the 253 patients. Following laparoscopic repair, 8 patients (8%) were admitted, as were 13 patients (10%) following open repair.
Overall satisfaction was similarly high for both laparoscopic and open procedures. Pain scores decreased significantly from the first to the seventh postoperative day, but there were no differences between groups (Table 2). Pain scores are shown in Figure 1; the distribution of scores was broad at 1 day and much narrower at 1 week following operation. Analgesic requirements, both quantity and duration, were similar for both groups. Following the laparoscopic procedure when compared with open repair, patients returned earlier to driving and work but not athletics.
When data were analyzed using Spearman rank order correlation (Figure 2), there was a significant inverse relation between age and pain score on the first postoperative day (r = −0.15, P = .02), with younger patients having higher overall scores. Although statistically significant, age accounts for only a small amount (2%) of the variability in first-day pain. Because patients undergoing laparoscopic repair were significantly younger than those who underwent open repair, outcome data were also analyzed for patients younger than 65 years (Table 3). In contrast to the entire series, younger patients who underwent laparoscopic repair had lower pain scores on the first postoperative day when compared with younger patients who underwent open repairs. However, there was no difference by the seventh postoperative day.
In a recent bulletin of the American College of Surgeons, Executive Director Thomas Russell wrote that "the surgeon of the future will . . . need to be aware of accurate outcomes data that demonstrate the short-and long-term effects of operative procedures . . . and share this information not only with . . . patients, but with payers . . . credentialing and privileging bodies. . . ."9 In that spirit, we and other investigators have undertaken to document outcome measures for groin hernia repairs, 800 000 of which are performed annually.10
Our data show that patient satisfaction and subjective pain can be quantitated and that these are similar for laparoscopic and tension-free open hernia repair when performed in selected patients. Satisfaction was high for both procedures. Pain scores decreased significantly from the first to seventh postoperative day. After laparoscopic repair, patients returned earlier to work and driving. Patients younger than 65 years experienced more pain than those 65 years and older. Younger patients had less pain with laparoscopic than with open repair, even though most underwent bilateral laparoscopic herniorrhaphies.
The number of days before returning to work and driving was significantly shorter in the laparoscopic group, but the laparoscopic patients were younger, and socioeconomic factors, which have been shown to influence return to work, were not studied. The age difference may also have affected the time to return to driving, which was shorter in the laparoscopic patients. However, when patients younger than 65 years were analyzed separately, there was no difference in return to driving.
Overall satisfaction, which reflects the entire operative and perioperative experience, is of great importance but difficult to quantitate. Satisfaction is most often measured by adjectives ("very satisfied," "moderately satisfied," or "dissatisfied"); these terms have been used to compare satisfaction data for laparoscopic vs open hernia repair.11- 13 Our data were collected by showing the patients a VAS and asking them to point to a face that corresponds with their level of satisfaction with the procedure. The patients readily identify the appropriate face, requiring less reasoning and rationalizing than a numerical scale.
Many factors affect pain, including type of operation, complications, age, tolerance, and cultural issues. Different anesthetic techniques also may affect postoperative pain. In our series, all patients in the laparoscopic group had general anesthesia, whereas most patients in the open group had local anesthesia. Of note, a randomized trial that compared local with general anesthesia in open hernia repair showed no difference in postoperative pain or recovery.14
Our series is the second to demonstrate that early postoperative pain is age dependent. Callesen et al15 showed a negative correlation between age and pain while moving and coughing during the first postoperative week. Bay-Nielsen et al16 suggested that older patients had a lower incidence of chronic pain.
In some reports, patients with inguinal hernia treated by a laparoscopic procedure had less postoperative pain than those treated by an open procedure.11,12,17- 19 Several authors have demonstrated this difference in the first postoperative week,12,19 but various measures of pain have been used, making it difficult to compare different series. Studies that compare pain response after laparoscopic repair and open hernioplasty16- 18,20- 23 have used verbal scales (mild, moderate, severe), simple rating scores (eg, 1-10), and the 100-mm VAS scores. In 14 prospective randomized trials that specifically assessed pain, 6 different measuring devices were used. Callesen et al15 used a 4-point verbal rank scale (none, slight, moderate, or severe pain). Wellwood et al11 used a simple integer score, ranging from 1 to 10. Others used questionnaires with descriptive terms16 or the absolute presence or absence of pain.19 Four studies18,21- 23 used a VAS with scores ranging from 0 to 100, asking the patient to rate the pain level along a 10-cm line. Six studies12,13,17,20,24,25 used a VAS that ranges from either 0 to 10 or 1 to 10.
The VAS score is superior because of its documented reliability and validity. It has been proven to be a linear scale for quantifying pain and to be accurate for serial measurements.2,3 Additionally, the absolute values of VAS measurements are clinically relevant. Carlsson26 found that the posttreatment pain score was more accurate in assessing interventional success than calculated reduction in scores for an individual patient. Also, several authors have found clinical relevance in grouping VAS scores. Most agree that VAS scores from 0 to 3 correspond to mild pain, for which patients do not seek analgesia. Scores from 4 to 6 represent moderate pain and 7 to 10 severe pain. When analyzing data in these broad categories, it is possible to identify clinically significant differences between treatment groups. In the moderate or severe ranges, several studies3,27,28 show clinical significance if the difference in pain score is at least 0.9 or 1.3 between groups.
Several investigators have used pain assessment by VAS to compare hernia techniques.12,13,17,20,24,25 The pain scores on postoperative day 1 ranged from 1.8 to 5.4 for laparoscopic repairs and 2.2 to 5.7 for open repairs. The variability of scores emphasizes the uniqueness of patient populations, but the differences in scores between techniques in each study were similar: 0.3 to 1.9 (postoperative day 1) and 0.1 to 1.5 (day 7). The difference in pain scores on the first postoperative day between laparoscopic and open technique in our patients younger than 65 years was 0.9 and was statistically significant. Calculated difference in scores is a useful comparative tool, using VAS for baseline scoring, because VAS is a simple and uniformly accepted method to assess pain and is used in most hospitals.
Our results cannot be used to prove the superiority of one technique over another. Our data were not randomized, and patients in the different groups were not matched for age, bilaterality, or method of anesthesia. Moreover, data were collected by the surgeon, to whom the patient might not choose to complain. However, the data show that subjective experiences following surgery can be quantified, allowing individual surgeons to counsel patients regarding realistic expectations in the postoperative period. VAS should be used in other investigations as an outcome measure, because it is universal, reliable, and easily understood by every reader.
Accepted for publication February 6, 2004.
This paper was presented at the Annual Meeting of the Western Surgical Association; November 12, 2003; Tucson, Ariz; and is published after peer review and revision. The discussions that follow this article are based on the originally submitted manuscript and not the revised manuscripts.
Corresponding author and reprints: Edward H. Phillips, MD, Department of Surgery, Cedars-Sinai Medical Center, 8635 W Third St, 795 W, Los Angeles, CA 90048 (e-mail: firstname.lastname@example.org).
Keith Millikan, MD, Chicago, Ill: This is a very timely study, since we are seeing, as mentioned yesterday, that the American College of Surgeons is actually going to start looking at laparoscopic vs open hernia repair. I'm not sure that's the right thing to look at, but I will talk about that in a little bit.
Pain is something that is very hard to measure. I looked at the visual analog scoring system, the first thing that came to mind was when I was 16 years old and taking my driver's license test, they had changed all of the signs, the colors, the shapes so that people who were uneducated or couldn't read English basically could drive and it could be compared universally now to all countries rather than having language as a barrier.
The second thing that came to mind was this weekend when my family was watching the new video release Disney movie when the fish was thought to be dead at the end of the movie, the two women in my family cried and the men didn't. Now you look at the scale, you have a smiley face on one side, you have crying on the other side and we have a population mainly of men within our hernia population, men usually don't feel it acceptable to cry so is that a good thing to look at in a hernia population that is in men? I'm not sure it is.
The object of this study was that we could look at subjective experiences and quantify them to improve comparison of techniques. They measured postoperative day No. 1 on postoperative day No. 7. Is that correct? Can someone actually quantify what their pain was a week later from postoperative day No. 1? They measured pain on postoperative day 7 and also measured satisfaction. I learned yesterday that satisfaction equaled being involved in a lawsuit or not where that wasn't mentioned in the manuscript. Is satisfaction for a procedure at 1 week or is it when the patient has chronic pain or recurrence at 1 or 2 years down the line? So I'm not sure that we are actually measuring satisfaction of the procedure. Maybe expectations that the patient had preoperatively at 1 week.
This generates several questions for the authors. (1) In your manuscript, although not depicted on the slides, 300 patients started out in this study, 47 were unable to complete the questionnaire, that is 16%, so why did the 16% have an incomplete questionnaire? Does this indicate that a significant portion of the population did not understand the VAS system? (2) Some patients come to the office with preoperative pain in hernias and others are totally asymptomatic other than a bulge. Should the patients be rated before surgery to obtain a baseline and to also find out if patients with preoperative pain are improved after the hernias are repaired? (3) As I said previously, can postoperative pain on day No. 1 be rated on day No. 7? (4) Is it fair to report return to work in a population which we are not told if they are blue-collar vs white-collar workers? We're told that one side of the coin was that they had an older population over 65 and another was a younger population. (5) Why are 115 out of the 253 or 45% of the patient population bilateral inguinal hernias? Is this not an abnormal hernia population bias and can we extend the VAS to a normal hernia population bias?
Dr Phillips, MD: Thank you for your questions. First, why 47 patients were dropped from the study. Most were patients who couldn't return on postoperative day 7, which was the day we chose to record the pain scores. The remainder had incomplete data sheets.
The patients intentionally were not introduced to the visual analog scale until after the procedure on the seventh postoperative day so as not to prejudice their perception of pain levels. We had performed a small pilot study in advance and determined that pain levels were most reproducible when gathered on postoperative day 7. We didn't want to record pain scores in the first 24-hour period because of the effects of the anesthetic. We found that a week later patients could accurately remember the pain levels they experienced the day after surgery without overemphasizing the significant pain experienced when coughing. Because pain scores vary with coughing or movement, we asked them to record the average pain levels for postoperative day 1 and 7.
There was no statistical difference in return to work. I agree that there might have been, if we had categorized the type of work people did and compared those subsets.
Regarding the high percentage of bilateral hernias, there was definitely a referral bias. Sometimes I'll get a referral for a possible laparoscopic repair and the patient has a unilateral hernia or a contraindication to laparoscopy and the patient will return to their original surgeon. Also, the primary care physicians in my practice area have learned that in general I perform laparoscopic herniorrhaphy for bilateral hernias or recurrent hernias.
Regarding satisfaction, it was explained again to the patient in terms of the overall surgical experience, so patients had the chance to voice exactly what they were happy about, what they weren't happy about, and what they would have liked to have been different. The VAS stimulated a useful discussion with patients, and it definitely has helped us to improve our practices.
Raymond J. Joehl, MD, Hines, Ill: For patients after open repair, did you find differences, right vs left, in when patients started driving? My bias is that, for patients who have a right-sided hernia, they won't be able to drive a car as quickly as patients who have a left-sided hernia repair.
The second question relates to anesthesia technique. Was the anesthesia technique the same among the different anesthesiologists in the ambulatory care center?
Regarding pain control, is it your practice to use narcotics after an operation or do you use NSAIDs [nonsteroidal anti-inflammatory drugs]? If you use both, was there a difference in pain control and perceptions of pain in your patients?
I noticed that in the laparoscopic group, there were 4 patients who had urinary retention. How do you establish an empty bladder during a laparoscopic procedure? Do you use Foley catheters or do you routinely have patients empty their bladder before going back to the operating room?
Dr Millikan asked about differences in pain perception between men and women using the visual analog scale (happy face, the sad face, the crying face). There were 15 women in the group, a small number relative to the larger group of males. Did the women rate their pain differently than men?
Finally, relative to our discussion yesterday about malpractice, were any of your patients so dissatisfied that they filed a malpractice claim?
Dr Phillips: Very good questions. We did not analyze the data by side of hernia, but we probably ought to do so. Regarding anesthesia technique, we do have an ambulatory protocol, though we did not look through the anesthetic records so I can't tell you for certain that the general anesthesia was identical for the laparoscopic cases. We use propofol for sedation during the local cases along with a mixture of Xylocaine and Marcaine.
Regarding outpatient control of the pain postoperatively, we prescribed Percocet as our standard oral medication. We did not use NSAIDs. In terms of the number of pain pills taken, our results, like most others on this subject, showed that number of pills and duration of use are similar for most patients.
We did not use Foley catheters. We asked the patients to empty their bladders preoperatively. We don't yet have the ideal algorithm to eliminate the problem of postoperative urinary retention, but we're looking at it.
We agree that there are gender differences in pain perception, but we didn't look at this specifically, as the number of women in our study was quite small. None of the patients has yet filed a malpractice claim.
James T. Dunn, MD, Santa Barbara, Calif: Our practice has sort of revolved into the same thing, but we are only doing laparoscopic procedures for bilateral hernias. One thing that we have started for unilateral hernias is using the On-Q pump for the first 48 hours where it's a constant infusion of Marcaine. I've been very pleased with that. Do you have any experience?
Dr Phillips: Drs Ken Waxman and Barry Sanchez presented a paper at the Wangensteen forum comparing saline and bupivacaine administered with this pump, which is a mechanical elastomer balloon attached to a very thin catheter that can be placed underneath the external oblique fascia or in the subcutaneous tissue. The local anesthetic infuses at 2 cc an hour and lasts for 48 hours. Dr Waxman placed the catheter in the subcutaneous tissue. The group with Marcaine infusion had less pain, but the control group patients had a pain level of 4, which is higher than our study and most others. It may have been because the control group had an iatrogenic 100-cc seroma. Perhaps they proved that seromas hurt—which we have all thought to be the case. The negative about the pain pump is that it has to be taken out after 48 hours; you're going to have to spend the time teaching the patient how to take it out or schedule an additional office visit when they still are in that first 3 days of pain. They may not want to get into the car and drive in to see their surgeons.
Lawrence A. Danto, MD, Truckee, Calif: The first principle of herniorrhaphy is that a tension-free repair is essential to minimizing recurrence and minimizing pain. Since that can be accomplished in 90% to 95% of patients without the use of mesh, why do you recommend using mesh in all of your patients?
My second question is actually for Dr Fujita; are you going to let Dr Phillips put in a foreign body that you will live with for the rest of your life next week when you develop your indirect hernia? And for the record, I have been involved as an expert in 2 cases now involving the use of mesh and severe postoperative pain.
Dr Phillips: We don't use mesh in all patients. For instance, a 16-year-old who has an indirect hernia probably only needs a sutured repair such as a Marcy. The other group in whom I don't like to put mesh is young women. They don't need it, and they have a higher risk of autoimmune diseases, fibromyalgia, or connective tissue pain. There is no question, though, that when you have familial hernia tendency and probable collagenase abnormalities, these patients are going to break down and have a high recurrence rate if mesh isn't used. If someone presents at age 50 with bilateral hernias and you do a modified Basini, they are going to have a 10% or higher chance of recurrence. If you do a Shouldice or a McVay repair, they are going to experience more pain because of the tension.
Now, why might mesh be associated with pain? Obviously, you can put a stitch around the ilioinguinal nerve and create a problem without the mesh. You can have the nerve pop up into the external oblique closure. The bottom line is that mesh provokes a tremendous inflammatory reaction, which can involve the nerves indirectly. That has led some people to recommend a Reeves repair, where the mesh is placed in the preperitoneal space. It is also important that you not leave the nerve in direct contact with the mesh. These are important details that affect the results of herniorrhaphy. But, in general, if mesh is used, the incidence of chronic pain that is not responsive to steroid injection is very small and acceptable.
James R. Debord, MD, Peoria, Ill: I think Dr Fujita said it all at the beginning of his talk when he pointed out that the results of all these different techniques of mesh repair of inguinal hernia are so good that we can't really measure the traditional things that we normally did, like recurrence rates, lengths of stay, and things like that. So, we find ourselves splitting hairs and trying to determine if somebody that took 5 pain pills had a better hernia experience than somebody that took a dozen and now you showed no real difference laparoscopically vs open. Seven or 8 other studies you alluded to didn't really show any benefit of laparoscopic inguinal hernia repair. I know that there is an increased cost. Could you tell us what the cost differential was in your laparoscopic vs open repairs, and then in view of all of this, why should anybody have a laparoscopic inguinal hernia repair?
Dr Phillips: They say a difference to be a difference must make a difference, and Dr Debord has challenged me. The actual cost difference was not examined in this study but has been studied at our hospital previously. It is more expensive by about $680, and we use reusable instruments and we don't use balloons or other expensive disposable items. As everyone knows, a hernia repair is not economically a winner for an ambulatory center or a hospital, and it can be a loser. So these numbers become very critical, but leaving aside the cost issue, when would I really want a laparoscopic hernia? The patients who unequivocally benefit are those with multiple recurrences, multiple failures despite good repairs. Some have come in with 3 or 4 recurrences. Anterior repair for a recurrence increases the chance of testicular ischemia and nerve injury; a laparoscopic repair is indicated. And a young surgeon such as myself with bilateral inguinal hernias should certainly have a laparoscopic repair.