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Vacuum-Assisted Delivery of the Fetal Head at Cesarean Section The cesarean section rate continues to climb despite multiple public health initiatives focused on lowering it. In the United States in 2003, 27.6 percent of all births were by cesarean section, a marked rise of 6 percent over the all-time high rate in 2002. The 2003 level is one-third higher than the 1996 level.i Although some feel the increasing cesarean section |
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rate protects many neonates from the various risks associated with difficult labors, this surgical procedure is not without its own risks, including increasing maternal blood loss, infection, incidents of placenta accreta, and uterine rupture . Another such drawback of the cesarean section is the traumatic or deliberate extension of the uterine incision while attempting to deliver the fetal head. Techniques to effect delivery under these circumstances have included pressure on the uterus, the use of a forceps blade (s), or additional incisions in the uterus—all of which can be traumatic to both mother and fetus.ii The use of the vacuum to assist in delivery of the fetal head at cesarean section to decrease these types of complications has been increasing in the recent years. However, this technique was originally reported in literature as early as 1962.iii Generally, there are two clinical scenarios in which vacuum-assisted delivery is utilized during a cesarean section. The first, and most accepted, is during a scheduled cesarean |
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section, in which the uterus is unlabored, the lower uterine segment is thick, and the fetal head is ‘floating’ or unengaged in the pelvis. Traditionally, the surgeon’s hand is inserted through the hysterotomy in an attempt to guide the fetal head through the incision and a significant amount of pressure is applied to the maternal abdomen to force the fetal head down into the surgeon’s hand. This is generally reported as the most uncomfortable portion of the procedure for the patient. In addition, this “manual-method” is associated with inadvertent extensions of the hysterotomy if the surgeon is not careful with the technique. Extensions of the uterine incision lead to greater blood loss due to the lateral anatomical position of the uterine vessels. Uterine |
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and sometimes cervical lacerations/extensions also lead to longer surgical time, and on the rare occasion loss of the uterus or even death.iv,v In addition, the use of vacuum at cesarean section contributes to a less invasive surgery because the surgeon can make a smaller uterine incision, does not have to introduce his/her entire hand into the incision and may not have to externalize the uterus during the repair. The second, but less optimal, situation is after the patient has become stalled in the second stage of labor and the fetal head is deeply engaged in the maternal pelvis. This procedure is more challenging because the flexion point (2-3 cm anterior to the posterior fontanelle along the sagittal suture) is often less accessible from the uterine incision after labor has progressed. The physician has to disengage the fetal head in the usual manual-fashion, place the cup over the flexion point, and then provide upward traction in a manner that promotes flexion of the fetal neck. Depending on the position of the presenting part (OP, OA, etc), flexion of the fetal neck can be more difficult. Overall, the procedure involves making the uterine incision and rupturing the membranes, palpating the fontanelles of the neonate, then placing the vacuum cup;over the flexion point and providing upward traction to deliver the fetal head through the hysterotomy. Generally, the flexion point is more accessible with a high, floating fetal head—which occurs in thick, non-labored uteruses. If it is low in the pelvis the surgeon may need to flex the fetal head upward with his/her fingers bringing the flexion point closer to the incision.vi,vii The contraindications for this procedure are similar to vacuum assisted vaginal delivery (i.e., prematurity—defined as less than 34 weeks, non-vertex presentation, known fetal bleeding, bone demineralization disorder, etc). As the cesarean section rate continues to climb and the trend in surgery continues to become less invasive, the procedure of using vacuum to assist delivery of the fetal head at cesarean section will continue to gain notoriety. |
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i Hamilton BE, Martin JA, Sutton PD. “Births: Preliminary Data for 2003” National Vital Statistics Report; Vol 53; Number 9; November, 2004. ii Nakano R. “Use of the vacuum extractor for delivery of the fetal head at cesarean section” Am J Obstet. Gynecol. October 1981 141(4) p. 475. iii Solomons E. “Delivery of the head by Malmstrom vacuum extractor during cesarean section” Obstet. Gynecol. 19 (1962) p. 201. iv Pelosi MA, Appuzio J. “Use of the soft, silicone obstetric vacuum cup for delivery of the fetal head at cesarean section” J Reprod Med. 1984 Apr;29(4):289-92. v Nakano R. “Use of the vacuum extractor for delivery of the fetal head at cesarean section” Obstet. Gynecol. October 1981 141(4) p. 475. vi Boehm F. “Vacuum Extraction During Cesarean Section” South Med Journ December 1985 78(12) p. 1502. vii Arad I. “Vacuum extraction at cesarean section – neonatal outcome” J. Perinat. Med. 14 (1986) 137 p.137-140 |
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