Objective Assessment of Small BowelAnastomosis Skill in Trainee General Surgeonsand UrologistsJyoti Shah, MRCS, MD, Yaron Munz, FRCS, Joanne Manson, BSc, MBBS,

Krishna Moorthy, FRCS, MD, Ara Darzi, MD, FRCSI

Academic Surgical Unit, Imperial College School of Medicine, St. Mary’s Hospital, Praed Street, London, W2 1NY, UK

Abstract

Introduction: The object of this study was to compare the technical ability of general surgery and

urology trainees to perform a small bowel anastomosis using a life-like bench model.

Methods: Forty subjects were divided into two groups based on the stage of their training. Spe-

cialist registrars (SpRs) trained for 1 to 3 years were defined as junior SpRs, and those with 4 to 6

years of training were defined as senior SpRs. They were asked to perform a small bowel

anastomosis on a standard latex model using the same equipment, suture material, and stan-

dardized instructions. Trainees were assessed by three trained observers based on a global rating

scale.

Results: Interrater reliability was 0.83 for the general surgical group and 0.88 for the urology group.

The median scores obtained by the junior SpRs were lower than those achieved by the senior

SpRs, and general surgical trainees consistently performed better than their matched urology

group. This difference reached statistical significance for the senior group.

Conclusions: Global rating scores provide a reliable, valid method for assessing technical skills

between specialties when performing a small bowel anastomosis. We provide reasons why

general surgeons may be more proficient at this task than urologists. These findings have possible

application to identifying trainees who need additional training and may also provide a mechanism

to ensure competence in this task.

I n 1812 Benjamin Travers wrote, ‘‘The union of a di-

vided bowel requires the contact of the cut extremities

in their entire circumference....’’1 Today, the question of

undertaking a one or two-layered small bowel anasto-

mosis remains controversial. When the mucosal layer is

included in the suture, there is a degree of intestinal

ischemic necrosis, which prolongs inflammation and

therefore delays intestinal healing.2 There is also a risk of

narrowing the lumen of the bowel during the two-layered

technique. Hence, most surgeons in our country employ

the interrupted serosubmucosal technique of small bowel

closure. This technique incorporates the submucosa in

the suture, which is regarded as the strongest of all layers

of the bowel.

The most feared complication of an anastomosis is

leakage. The cause of such leakage is failure of any one

of the following traditional trilogy: adequate blood supply,

no tension, accurate apposition of tissue.

Traditionally, operating skills are learned under

supervision in the operating theater. In the current climate

many skills are being taught in a more formal setting,

such a skills laboratory, where there is less pressure than

in the real situation. Surgical workshops serve a key role

Correspondence to: Jyoti Shah, Academic Surgical Unit, ImperialCollege School of Medicine, St. Mary’s Hospital, Praed Street, London,W2 1NY, UK, e-mail: jyoti.shah@imperial.ac.uk

� 2006 by the Societe Internationale de Chirurgie World J Surg (2006) 30: 248–251

Published Online: 21 January 2006 DOI: 10.1007/s00268-005-0074-1

in teaching and can be used as part of a structured

training program. The Basic Surgical Skills Course in the

United Kingdom is mandatory for all basic surgical train-

ees and is an essential requirement for sitting the final

component of the Membership of the Royal College of

Surgeons (MRCS) examination. Small bowel anastomo-

ses are taught during this course in a standardized

manner using porcine small bowel.

It is, however, becoming more difficult to justify the

use of animals when alternative bench models exist.

Such bench models have the advantage of reduced

costs, portability, and reduced ethical and moral dilem-

mas; and they can be re-used. These models are also

standardized and can be exactly replicated.

Currently there is no formal assessment of techni-

cal skills at any stage of surgical training. Synthetic

models can also be used for this purpose, allowing

constructive feedback to trainees and identifying defi-

ciencies in the training program. The Objective Struc-

tured Assessment of Technical Skills (OSATS) is one

of the most successful methods for evaluating skills

objectively and has been found to have high reliability

and validity.

OSATS was originally developed by the University

of Toronto and has been used to demonstrate that

learning technical skills on a cadaver and on bench

models is equivalent.3 There are two parts to OSATS:

a structured task-specific checklist and an eight-

parameter global rating score. The global rating scale

judges general categories of surgical ability and has

been shown to have greater reliability and validity than

the task-specific checklist.4 Based on this scale the

maximum score possible is 40; a score of 24 is re-

garded as competent.

Small bowel anastomoses are performed regularly by

general surgical and urologic trainees. This is a task that

is also formally taught in many courses in the United

Kingdom at both basic and higher surgical training levels.

The purpose of this study was to assess objectively

the technical skill of trainee general surgeons and urolo-

gists when performing a small bowel anastomosis and to

compare their performance.

MATERIALS AND METHODS

Subjects

Two groups of subjects were recruited for this study:

general surgery (GS) specialist registrars (SpRs) and

urology SpRs. Each group was divided into junior SpRs

(during years 1–3 of their training) and senior SpRs

(during years 4–6). Specifically, the groups consisted of

11 junior urology SpRs, 8 senior urology SpRs, 10 junior

GS SpRs and 11 senior GS SpRs.

Materials

The synthetic bowel model used for this experiment

was made of latex and has a luminal diameter of 20 mm

(Limbs & Things, Bristol, UK). The model was held in a

standard jig (Fig. 1).

The anastomosis technique was standardized accord-

ing to the Royal College of Surgeons of England guide-

lines: placement of stay sutures at each end; the use of

hand-tied interrupted serosubmucosal sutures placed

approximately 5 mm apart; and four throws to each

suture.

Each subject used the same suture material: 3:0 Bio-

syn (monofilament glycomer; U.S. Surgical, Norwalk, CT,

USA) on a V20 (26 mm, one-half circle, taper point)

needle. They were each asked to hand-tie all four throws

to each knot.

Subjects were responsible for choosing the appropriate

instruments, and no assistance was provided. The sub-

jects had to follow and cut the sutures by themselves. For

the instruments, appropriate choices of forceps (deBakey

forceps) and distractors (toothed forceps) were provided.

Outcome Measures

The performance of the task was videotaped using a

digital camera and later analyzed using a global scoring

sheet as per the OSATS technique. All digital videotapes

were analyzed by three trained observers in our depart-

Figure 1. Small bowel anastomosis model.

Shah et al.: Small Bowel Anastomosis Skill of Trainees 249

ment who had had previous experience with OSATS

scoring. The trainees was identified by number. To

maximize anonymity, the videotapes showed only the

hands of the subjects performing the task, and there was

no sound.

The final score was an average of the three scores

generated by the observers. A maximum of 40 was

possible, and a score of 24 was considered competent.

Statistical Analysis

Statistical analyses were performed using StatView

(SAS Institute, Cary, NC, USA). Internal consistency,

which is a measure of the interrater reliability of the

examinations, was calculated using Cronbach’s alpha.

Previous experience in this area has demonstrated that

the data obtained are nonparametric. The Mann-Whitney

U-test (MWU) was used for comparisons between two

groups. A value of P < 0.05 was considered statistically

significant.

RESULTS

The interrater reliability for both data sets was high

(0.88 for urology and 0.83 for the general surgery data).

In this context, tests with alpha indices >0.8 are consid-

ered reliable and can be used for certification.5

The median score obtained for the junior GS SpRs was

higher than that obtained for the urology junior SpRs

(Fig. 2). This difference did not reach statistical signifi-

cance (P = 0.7248, MWU). Both groups also scored

above 24, which is considered competent.

We found a similar but statistically significant result for

the senior SpR group (P = 0.0057, MWU) (Fig. 3). Sur-

prisingly, the median score for the urology senior group

was below the level considered competent.

DISCUSSION

One of the most common methods for assessing sur-

gical skills is to observe and comment on the operator’s

performance. In the absence of a structured grading

system to assess performance, this process is unreliable

and subject to bias.

Assessment in the operating theater has inherent

problems related to the lack of standardization. Patients

can have aberrant anatomy, or problems may arise from

adhesions; furthermore, there are time constraints when

teaching in the operating room. This, coupled with the

ethical issues of using patients for training, has taken the

assessment process out of the operating room and lar-

gely to bench models. The latter provide standardization

of the task’s performance, with no risk of technical inad-

equacy that might endanger the patient.

The finding that general surgery trainees seem to score

higher on the global rating scales for a small bowel

anastomosis is not surprising. Both junior and senior GS

SpRs perform this task with greater frequency than urol-

ogy SpRs. The occasions on which urologists undertake

this task are comparatively infrequent and largely limited

to situations of neobladder or conduit formation. How-

ever, both groups of trainees should be considered

competent at this procedure if they are to undertake it.

The observed difference reaches statistical significance

when comparing the senior general surgery and urology

groups. Additionally, the median score for the senior

urology SpR group falls below the defined level of com-

20

22

24

26

28

30

32

34

Mea

n sc

ore

Urology SpRs Gen Surg SpRs

Figure 2. Global scores for junior specialist registrars (SpRs) inurology and general surgery.

21

22

23

24

25

26

27

28

29

30

31

Me

an

sc

ore

Urology SRs Gen Surg SpRs

Figure 3. Global scores for senior SpRs in urology and generalsurgery.

250 Shah et al.: Small Bowel Anastomosis Skill of Trainees

petence. This could be due to a number of factors.

Urology senior SpRs tend to undertake more specific

training in designated areas of urology, such as in

endourology or andrology; they thus perform small bowel

anastomoses less frequently than if they were doing a

junior general urology rotation, as in the early stages of

their training.

Urologists usually perform a small bowel anastomosis

when undertaking a cystectomy and formation of an ileal

conduit. For this operation, there are ‘‘unofficial’’ roles for

all levels of urology trainees present in the operating

theater. For example, the most junior trainee present,

who may be a junior SpR or even the senior house officer,

is usually allowed to perform the anastomosis.

The junior SpRs would have more recently attended

a Basic Surgical Skills course, such as those arranged

by the Royal Colleges of Surgery. Thus the urology

trainees are therefore more proficient at this task than

the senior urology SpR group, whose median score is

lower. Hence, without practice, senior urology trainees

may become de-skilled at performing a bowel anasto-

mosis. With increasing subspecialization in both general

surgery and urology, it is crucial that surgeons do not

undertake procedures they are not regularly performing.

For example, should a general surgeon who specializes

in breast surgery undertake a small bowel anastomosis

in the emergency setting? Such assessments could

eventually be used to demonstrate proficiency in these

procedures.

To our knowledge, this is the first study to undertake a

direct surgical specialty comparison. We have shown that

there are differing levels of competence among trainees

of two surgical specialties for a standard, basic task. At

this stage we are unable to comment on whether the

observed differences can be applied to clinical practice.

We were also interested to find that senior urology

trainees were defined as ‘‘incompetent’’ based on the

scoring system.

Indeed, if these results are found in clinical practice,

other questions are raised. For the formation of an ileal

conduit, should urologists be calling on the skills of gen-

eral surgeons, who regularly undertake bowel anasto-

moses, for this stage of the procedure? Of course, this is

not feasible when the entire workforce is stretched for

time.

With the introduction of streamlined surgical training, it

is likely that trainees will learn to specialize in techniques

at an early stage. Could early specialization of trainees be

deleterious to their later competence? Such objective

assessments of technical skill have the potential to be

applied for quality assurance and to avoid the possibility

of surgeons becoming de-skilled.

CONCLUSIONS

There are significant differences between urology and

general surgery specialist registrars when measuring

their technical skill at performing a small bowel anasto-

mosis. This result suggests the growing need for regular

assessments of surgical performance if higher standards

of quality control and patient safety are to be achieved.

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Shah et al.: Small Bowel Anastomosis Skill of Trainees 251