Studies objectively comparing lithotomy and prone positions regarding surgeon comfort, ergonomics, patient comfort, and position related complications are scarce.
The patients posted for surgery of either fistula in ano, hemorrhoids, or were included in this study. Subjective Mental Effort Questionnaire (SMEQ) and Local Experienced Discomfort (LED) scale were used to score the level of mental and physical stress among the operating surgeon, assistants, and the scrub nurse. Other parameters studied were the exposure of the operative site, patient comfort level, and position-related complications.
Thirty patients were operated in each position. Mean ± standard deviation of jackknife prone vs. lithotomy surgeon SMEQ score (15.6 ± 10.4 vs. 107.0 ± 11.5, P < 0.05) and LED score (1.8 ± 1.5 vs. 6.7 ± 0.5, P < 0.05) were found to be statistically significant. Prone vs. lithotomy assistant SMEQ score (29.1 ± 13.1 vs. 100.6 ± 8.7, P < 0.05) and LED score (4.6 ± 1.1 vs. 7.4 ± 0.8, P < 0.05) were also found to be statistically significant. SMEQ (10.0 ± 0.0 vs. 20.6 ± 2.5, P < 0.05) and LED scores (1.1 ± 0.3 vs. 3.3 ± 0.5, P < 0.05) of scrub nurses and LED scores (2.5 ± 0.5 vs. 6.3 ± 0.7, P < 0.05) of patients were also statistically significant. Exposure of the operative site was significantly better in the prone position (5.0 vs. 2.1, P < 0.05).
Significantly better SMEQ, LED, and exposure score suggests the superiority of jackknife prone position over the lithotomy in terms of significantly less mental and physical stress to the operating surgeon, assistant, and scrub nurse; better ergonomics, and excellent exposure.
Lithotomy and jackknife prone are the 2 commonly used positions for perianal surgeries, the former being conventionally more used [
In contrast, the jackknife prone position can potentially provide excellent exposure, better ergonomics, exchange of instruments under vision, and avoid pooling blood in the operative field. Earlier, we use to perform surgeries of benign anorectal diseases like fissure, fistula, and hemorrhoids in a lithotomy position, but gradually have shifted to the jackknife prone position. Dr. Louis Buie first popularized the jackknife prone position for colorectal procedures [
The Institute Ethical Committee approved this prospective study, and we registered the trial with the clinical trial registry of India (CTRI/2019/12/022347). Written consent was obtained from all participants.
The enrolment started in December 2019, and the last patient was recruited in March 2020. The patients aged 18 years or older who were scheduled to undergo perianal surgery for fistula in ano, hemorrhoids, and fissure in ano were evaluated for inclusion in the study. The patients with contraindications to either positions or declining consent or were not able to understand the nature of the study were excluded. In the absence of previous similar trials, we planned this pilot study.
We included 30 patients in each group. The sample size was calculated based on the study by Browne [
The patients operated in the lithotomy position were made to lie supine with buttocks at the table’s lower break. The hip joints were flexed 90° and abducted at 30° and knees, bent 70° to 90°. The calves and lower thighs were supported on a padded leg shell, and the hands tucked at the side. The buttocks were lifted from the table with padded supports. In contrast, while operating the patients in jackknife prone position, patients were made to lie in the jackknife prone position with iliac crest lying below the operating table’s break. We also split the patients’ legs by 40° to 60°, and buttocks were held apart by elastic tape. Adequate paddings were provided at the pressure areas to avoid neuromuscular complications. The patients were allowed to keep their hands in a comfortable position away from the area of interest. However, due care was taken to secure the intravenous cannula and other attachments.
Subjective Mental Effort Questionnaire (SMEQ) and the Local Experienced Discomfort (LED) scale were used to score the level of mental and physical stress among the operating surgeon and the assistants (
We evaluated a total of 108 patients for inclusion in the trial. Forty-three patients refused to participate; 3 refused to sign the written consent form, and 2 could not understand the nature of the study (
Ergonomics deals with the study of human activities and behavior in the working environment [
Patients have to be turned to the prone position after intubation while operating the patient under the jackknife prone position, during which there is always a chance of accidental dislodgement of the endotracheal tube. In this situation, patients have to be turned again to a supine position to secure the airway. Although these events are rare nowadays with expert anesthesia care, the airways need to be secured with extreme care. Apart from this demerit, there are several advantages of jackknife prone position over lithotomy. The surgeons operating in lithotomy position remained stuck between the legs of the patients, with restricted mobility. The assistants also have restricted access to the operation site. The assistants have to stand in an awkward position to keep the operative area well exposed, causing physical and mental discomfort. The soiling of the operative field with blood adds to the limitations of this position. In contrast, in a jackknife prone position, the surgeon and assistants stand comfortably by the patient’s side, without restricting mobility.
Despite several advantages of jackknife prone position over the lithotomy, acceptance of jackknife prone position for perianal procedures is extremely low, at least in our center. Researchers have compared the operation time, blood loss, rectal perforation rate, circumferential resection margin, and oncological outcome of APR, in lithotomy and jackknife prone position, with several advantages in the later [
Most of our benign perianal procedures are performed under perianal block as a daycare procedure. We resort to regional or general anesthesia if the patients refuse to operate under local anesthesia or find the procedure unsuitable for completing under local anesthesia.
The operating surgeon’s physical stress level, measured by the LED scale, was significantly better while operating the patients in a jackknife prone position. The operating surgeon operated on the patients in lithotomy by sitting on a stool between the patient’s legs. However, he had to twist, extend, and bend multiple times to either approach the operating site or get the desired instruments. The LED scale reflects the physical discomfort. In contrast, the surgeon comfortably operated on the patient by standing between the patient’s legs and lying in a jackknife prone position. Constant soiling of the field by blood and inadequate exposure of the operative field in the lithotomy position, as reflected by the exposure scale [
The observations were similar to both the assistants and the scrub nurses. The assistants either stand behind the surgeon or on one side of the limb when operated in lithotomy. When they are standing behind the surgeon, the vision is obstructed by the surgeon and by the lower limb when standing on one side of the patient. In both situations, it gets difficult for the assistant to assist actively. Their mental and physical discomfort increases further in the lithotomy position due to improper lighting and exposure.
Scrub nurses also reported significantly lower physical and mental stress levels in a jackknife prone position. In lithotomy, the scrub nurse stands behind the surgeon with the surgical tray and passes the instruments and mops over the shoulder of the surgeon, potentially compromising the sterility. It also increases the chances of needle stick injury and other injuries related to the instruments. The entire surgical team gets enough space to visualize the surgical field and assist actively in the jackknife prone position.
Interestingly, patients also reported significantly lower physical stress levels in jackknife prone positions. Over 70% of patients operated in lithotomy complained of mild pain and numbness over the calves. Eight patients (26.6%), who got operated on in a jackknife prone position, complained of mild neck pain intraoperatively. None had any intraoperative or postoperative complications in either group. However, since all the patients were operated on under local anesthesia, this finding may not be extrapolated. A study with a more significant number of patients being operated on under anesthesia can help to answer this question.
The operating time was 12 minutes shorter in jackknife prone than in the lithotomy position. This decrease in the time is probably because the operative site’s exposure was significantly better in a jackknife prone position; both the surgeon and the assistants were less stressed and participated actively in the procedure. There is also less soiling of the operative site with blood.
We faced difficulty in recruiting the patient for this trial. We explained that one position could be more uncomfortable than the other to them and the surgical team. It also revealed that the chances of complications in one position could be theoretically more than the other. The patients asked about the preference of the operating surgeon and the usual position adopted by him. Since our choice is the jackknife prone position, many patients opted for a jackknife prone position and refused randomization, which could be a serious limitation of this study. Secondly, a single surgeon operated on all the patients, and his inherent preference was to the jackknife prone position. Hence there is a fair chance of a bias toward the jackknife prone position. However, it’s worth mentioning that the assistants and the nursing assistant were exposed equally to both situations. A total of 11 surgical residents and 7 nursing staff participated in the study, which adds to the merit of the study. Hence, even if the surgeon’s scores are biased, the same may not be valid for the assistants.
Similarly, patient scores should also be free of any bias. Since the majority of the patients were young males, this could lead to selection bias. However, it is essential to realize that around 80% of the patients who attend our coloproctology clinic are young males. So, it is not possible to overcome this bias. We suggest a study with a large sample size to include many females and elderly patients to reduce the selection bias. More number of surgeons can also be included in this larger study to reduce preference-related bias.
The LED score developed by Corlett and Bishop [
All the scores measured are subjective, and the ergonomics were not assessed objectively. Although this can be a limitation of the study, this does not devalue the study. This was a pilot study and can be repeated with the surgeons who do not prefer the jackknife prone position. A similar study can be planned with large sample size, and ergonomics/comfort can be measured objectively. van der Schatte Olivier et al. [
To conclude, this pilot study results suggest that the jackknife prone position provides excellent exposure, better ergonomics, significantly less mental and physical stress to the operating surgeon, assistant, and scrub nurse compared to the lithotomy position. The jackknife prone position is also more comfortable for the patient being operated under local anesthesia. It can be preferred in all benign perianal procedures unless it is contraindicated. However, further studies are needed with a larger sample size to include the females and elderly patients, measure the ergonomics objectively by wearable devices, and include multiple surgeons to avoid biases.
No potential conflict of interest relevant to this article was reported.
None.
Subjective Mental Effort Questionnaire scale.
Local Experienced Discomfort scale.
CONSORT (Consolidated Standards of Reporting Trials) diagram for this study.
Baseline characteristics
Characteristic | Applied method |
Procedure |
||||
---|---|---|---|---|---|---|
Jackknife prone | Lithotomy | P-value | Jackknife prone | Lithotomy | ||
Age (yr) | 42.0 ± 10.2 | 40.6 ± 12.1 | 0.629 |
|||
Male:female | 28:2 | 27:3 | > 0.9 |
|||
Body mass index (kg/m2) | 26.0 ± 2.7 | 27.0 ± 3.2 | 0.196 |
|||
Fistulas | 24 | 25 | > 0.99 |
|||
Intersphincteric | 3 (12.5) | 4 (16.0) | Fistulotomy-3 | Fistulotomy-4 | ||
Trans sphincteric | 20 (83.3) | 21 (84.0) | FPR-12, LIFT-8 | Fistulotomy-2, FPR-11, LIFT-7, ERAF-1 | ||
Supralevator | 1 (4.2) | 0 (0) | LIFT-1 | NA | ||
Extra sphincteric | 0 (0) | 0 (0) | NA | NA | ||
Hemorrhoids | 4 | 3 | > 0.99 |
|||
Grade 1 | 0 (0) | 0 (0) | NA | NA | ||
Grade 2 | 0 (0) | 0 (0) | NA | NA | ||
Garde 3 | 3 (75.0) | 2 (66.7) | Stapled hemorrhoidopexy-3 | Stapled hemorrhoidopexy-2 | ||
Grade 4 | 1 (25.0) | 1 (33.3) | Open hemorrhoidectomy- 1 | Open hemorrhoidectomy- 1 | ||
Fissure | 1 | 2 | 0.618 |
LIS-1 | LIS-2 | |
Anal stenosis | 1 | 0 | > 0.5 |
V-Y plasty-1 | NA |
Values are presented as mean±standard deviation, number only, or number (%).
FPR, fistulectomy with primary sphincter reconstruction; LIFT, ligation of intersphincteric fistula tract; ERAF, endorectal advancement flap; NA, not applicable; LIS, lateral internal sphincterotomy.
P-values were analyzed by
t-test and
chi-square test.
The scores of Subjective Mental Effort Questionnaire (SMEQ) and Local Experienced Discomfort (LED) scale
Parameter | Jackknife prone | Lithotomy |
---|---|---|
Surgeon | ||
SMEQ | 15.6 ± 10.4 | 107.0 ± 11.5 |
LED | 1.8 ± 1.5 | 6.7 ± 0.5 |
Assistant | ||
SMEQ | 29.1 ± 13.1 | 100.6 ± 8.7 |
LED | 4.6 ± 1.1 | 7.4 ± 0.8 |
Scrub nurse | ||
SMEQ | 10.0 ± 0.0 | 20.6 ± 2.5 |
LED | 1.1 ± 0.3 | 3.3 ± 0.5 |
LED score of the patients | 2.5 ± 0.5 | 6.3 ± 0.7 |
Exposure of the operative site | 5.0 ± 0.0 | 2.1 ± 0.4 |
Values are presented as mean±standard deviation.
All P < 0.05 (by t-test).