By John C. Hobbins, MD
When moving from New Haven to Denver, I noticed that the technique of performing a Cesarean section was almost identical. An informal poll of colleagues at other institutions revealed that, with minor variations, there seems to be a common way of performing Cesarean section in the United States that has changed little over the last 20 years. Perhaps it is time to re-evaluate this technique, step-by-step.
The Skin Incision
Most physicians use a Pfannenstiel incision whose outline approximates the upper margin of a bikini. The Joel Cohen incision, which is used on occasion when doing a fast entry for fetal distress, is less curved than a Pfannenstiel and crosses the mid-line an inch above the Pfannenstiel. Although many have obsessed over the benefits of one vs. the other, the real difference between the 2 seems to be cosmetic (eg, the chances of seeing the incision when one is wearing a bathing suit). Frankly, I am certainly the last one to comment about women’s fashions, but almost anything can hide the slightly higher incision. The incision, which should be passé, is the vertical one, which is billed as the way to get into the uterus the fastest. However, it is really not any faster than the Joel Cohen incision and is a cosmetic disaster.
Traversing the Subcutaneous Tissue
This is usually accomplished by a sharp knife dissection down to the fascia, which is exposed in its entirety throughout the length of the incision. The 2 little vessels that are incised laterally with impunity are forgotten quickly, but they will often bleed throughout the rest of the procedure unless coagulated or tied off.
Traversing Fascia to Peritoneum
The most common way to accomplish this is to make a nick in the fascia in the mid-line and to extend the incision out laterally with scissors under direct visualization. In primary Cesarean sections, the recti are manually reflected laterally, but with repeat Cesarean section one has to chip away at the scar tissue in the mid-line to get a plane that can be opened sometimes manually with encouragement.
Entering the Peritoneum
This is accomplished either by poking a finger through the tented up peritoneum or by pulling this thin layer upward with tissue forceps and entering carefully with a scalpel or scissors. Reflecting the peritoneal portion of the "bladder flap" downward appears to be a standard technique. Some will stop this endeavor just below where the incision is planned in the uterus, but most others with take this down bluntly and sharply to the symphysis pubis.
The Uterine Incision
Transverse incisions are usually made initially below the bladder flap reflection in the mid-line and carried out laterally in a "smile" by scissors or by "east/west" manual manipulation accomplished by a single finger of both hands. Vertical uterine incisions extend from just below the bladder flap in the mid-line upward to a point where the lower uterine segment ends (in term uteri) and this virtually always necessitates the use of strong scissors.
Removal of the Infant
Here there are many variations on the common theme. After membranes are ruptured, the operator’s hand is inserted through the incision with palm up and insinuated downward under the presenting part, which is then lifted upward through the incision. Some operators will use a vacuum extractor with large babies once the vertex is exposed, to diminish the chances of incision extension. An uncommon variation (but one I really like) is to dislodge the head vaginally just before the operation begins to diminish the changes of extension of the incision laterally by the forceful maneuvering necessary to deliver a well-entrenched head in the pelvis.
Closure of the Uterus
One layer vs. 2 layers. Many surgeons feel that the uterine incision is stronger if 2 layers are applied. Frankly, in a transverse incision, if big bites of tissue are incorporated into a single layer there is little evidence to support the concept that if "some is good, more is better." Although, a recent nonrandomized trial suggests a single layer closure is associated with a higher risk of later uterine rupture, there is no evidence from a randomized trial that a single closure is more risky. In vertical incisions, sometimes a third layer is required in the upper, thicker segment of the uterus.
Locking vs. nonlocking. Most operators today use a continuous locking suture to close the uterus. The misconception is that the locking suture provides the best hemostasis. This is not necessarily true in the uterus, and all that locking does is to compromise the microcirculation of tissue in the margin, whose job is to heal into a strong postoperative scar.
The real major evolution in Cesarean section technique over the last decade has been to abandon closure of the bladder reflection and the abdominal peritoneum because it is clear that reperitonealization will occur in spite of attempts to put things back the way they were.
Fascia and Subcutaneous Closure
Although there are some minor variations, the most common technique is to close the fascia in one layer with 1 or 2 running sutures. Some will close the subcutaneous tissue with interrupteds or a running suture. Some will not. It probably does not matter.
Here is where everyone has his or her own pet techniques so I will not touch upon this, as it has no great clinical effect.
It is becoming clear that with Cesarean section the less one does, the better the outcome. Two recent examples come to mind. A study emanating from Vienna compared outcome when the bladder flap was vs. when it was not taken down.1 This maneuver takes extra time and creates a space in a vascular area that is ideal for hematoma formation. Investigators randomized patients according to whether a bladder flap was reflected. The procedure added an average of 5 minutes to the operation and resulted in a statistically significantly greater hemoglobin drop, a 50% increase in microhematuria, and a greater need for postoperative analgesics.
On another note, our colleagues in Milan, Italy, adopted a well-conceived hybrid technique of Cesarean section and compared it, in a randomized trial, to their usual technique, which was essentially the same as that performed in the United States.2 This hybrid method involved a Joel Cohen entry and components described by an obstetrician named Stark. It features an almost complete avoidance of retractors, not cutting the superficial subcutaneous arteries, "blind" scissor opening of the fascia, minimal (1") mobilization of the bladder flap with a sponge, gentle removal of the fetal head, single layer closure of the uterus and fascia, no reperitonealization, and stay sutures thru the skin and subcutaneous tissue.
Halfway through they stopped the study and abandoned the old technique because the hybrid was 20 minutes shorter, significantly less blood loss was encountered, and postoperative recovery time was almost halved.
It may be difficult to modify a surgical technique that has been drummed into every American obstetrician, but it is at least worth discussing.
1. Hohlagschwandtner M, et al. Obstet Gynecol. 2001;98: 1089-1092.
2. Bujold E, et al. Am J Obstet Gynecol. 2002;186(6): 1326-1330.Attention Readers
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