Academic OB/GYN

Junes’s Green Journal had an interesting article on vertical versus transverse skin incisions for emergent cesarean deliveries that seemed worth some comment.

The point of the article was to look at a large retrospective cohort of emergent cesarean deliveries, stratify them by vertical or transverse skin incision, and then look at operative times and patient and fetal outcomes.  This dataset was drawn from recorded data from many different centers, as part of the MFMU Network system of studies.

The study looked at 3,525 emergent cesarean deliveries performed in 1999 and 2000 at the study centers.  Of these deliveries 2,498 (70.9%) were done with transverse abdominal incisions and 1,027 (29.1%) were done with vertical incisions.

The two groups were similar in age, but differed in BMI, with patients having vertical incisions being more likely to have larger BMIs (31.5 v 32.4, p = 0.02).  There was also significant differences in rare between groups, with vertical incision patients being more likely to be Hispanic than transverse incision patients (Transverse – white 37%  AA 47%  Hispanic 11%; Vertical 16% white 41% AA  Hispanic 40%, p < 0.001.)  Transverse incision patients were also more likely to be nulliparous (49% vs 43% p = 0.002.)

The groups also differed in number with previous cesarean deliveries, with the vertical incision group being somewhat more likely to have had previous cesareans.

Surgeries with vertical incisions were done more quickly than transverse incisions, with median incision-to-delivery intervals of 5.5 minutes with transverse versus only 3.5 for vertical for primaries, and 6.8 minutes vs 5.1 minutes for repeat cesareans.   The incision to closure interval was longer for vertical incisions, 50 minutes vs 46 minutes in transverse incisions in primary sections, 67 vs 56 minutes in repeat cesareans.

Contrary to what one might think, there was no differences in maternal injury with the two groups, with intraoperative injury occurring in 0.7% of each group.  Postpartum endometritis was more common in the vertical group 15% vs 11%, p = 0.006.  Wound infection, hematoma, ileus were similar between groups.  The vertical group had more need for transfusion, 7% vs 5%, p = 0.01.

Low umbilical artery pH < 7.0 was  more common in the vertical group 10% vs 7%, p = 0.02.  Frequency of hypoxic encephalopathy was greater in the vertical group 3% vs 1%, p < 0.001. Babies born via vertical incision were more likely to need intubation in the delivery room, 17% vs 13% p = 0.001. There were no differences in  need for infant CPR, neonatal death, or 5 minute apgar scores (though there was as trend towards lower apgars for the vertical group, 5% vs 4% p = 0.06.)

OK – so what does this all mean?

This is what I get out of it:

1. In a very large set of data, gathered at teaching centers where residents are doing the operating, surgeons seem to be able to get babies out a bit quicker with vertical incisions than with transverse incisions.

2. Contrary to what I would have thought, there did not seem to be a greater number of maternal injuries with the vertical incisions.  This is surprising to me as the worst bladder injury I have seen came from an overzealous vertical incision during a crash cesarean.  Perhaps I am just mentally scarred from one event.

3. The fetal outcomes data is not worthwhile.  The data is quite biased by the indication for the crash cesareans.   People already have a pre-existing thought that a vertical incision can lead to a quicker delivery, and so it makes sense that they would have done more verticals in more severe cases where it was felt that every second counted.  As such, it is not surprising that the vertical incision babies had worse gases, were more likely to be intubated, and had a higher frequency of neonatal encephalopathy.  To me, this says nothing about the effect of the incision, especially given that the group with the worse outcomes had quicker delivery times.

But here’s the thing:  It seems very odd to me to aggregate some huge dataset to try to describe something that is so individual from surgeon to surgeon.  Each surgeon has a pretty good idea of what they can do quicker, and a large data set that describes thousands of different surgeons doesn’t really imply anything about each individual.   I can say without question that in a primary section I can reliably deliver an infant through a transverse skin incision in less than 60 seconds.  Perhaps I could do it a little faster with a vertical, but to me those few seconds don’t seem worth it.  Does this mean that everybody else should do the same thing as I?  Of course not – we are all different surgeons and some people might be able to do a vertical much quicker than they could do a transverse incision.   There are factors that might change our mind for each patient as well, such as previous surgeries, or even previous vertical incisions.  But ultimately, each surgeon knows more about their individual performance than any paper can tell them about themselves.  And for that reason, I don’t find this data all that helpful.

To me, the thing that will be quickest is usually what one knows the best.   Most gynecologists have done hundreds if not thousands of transverse entries, and if need be they can do them very quickly.  Most gynecologists, especially residents (who were described in this case), have not done as many vertical incisions, and likely can accelerate a technique they already know better than they can try to rush something they are not as comfortable with.  That being said, the data did show than on the average (or on the median), verticals were faster.  Go figure.

So what do you all do?

Comparison of transverse and vertical skin incision for emergency cesarean delivery.   Wylie BJ, Gilbert S, Landon MB, Spong CY, Rouse DJ, Leveno KJ, Varner MW, Caritis SN, Meis PJ, Wapner RJ, Sorokin Y, Miodovnik M, O’Sullivan MJ, Sibai BM, Langer O; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU). Obstet Gynecol. 2010 Jun;115(6):1134-40.