Clinical Tips of Cesarean Section in Case of Breech, Transverse Presentation, and Incarcerated Uterus

In cases of cesarean section for an incarcerated uterus, the success of the operation depends on whether cervical elongation and retroverted uterus can be detected preoperatively and whether the cesarean section procedure is smooth and minimally invasive to the maternal body. Incarceration of the uterus may not be recognized in early pregnancy. However, when extreme anterior-upward displacement of the cervix of the uterus or globular tumorous sensation in the posterior vaginal fornix is found by vaginal examination on admission for cesarean section or preoperative examination before departure from the hospital ward, the uterine cervix located anterosuperior to the bladder should be further examined by transabdominal ultrasonography to determine whether there is either elongation of the cervix or incarceration of the uterus. The height of the lower uterine segment and site of the uterine cavity should be examined by ultrasonography to decide the cutting level of the uterus before the operation. If a diagnosis of the incarcerated uterus was made at term, elective cesarean section should be performed with special attention. When a cesarean section is performed without the recognition of an incarcerated uterus, it might be difficult to deliver the fetus because it will not reach the uterine cavity and consequently result in fetal asphyxia. Several complications such as complete cutting of the cervix or the vagina, extended uterine incision, incision on the posterior wall of the uterus through the vagina, or laceration due to massive hemorrhage may occur, because the lower uterine segment is dislocated extremely to the upper site compared with that in an ordinary cesarean section. 3 4 6 Therefore, a strategy for a safe cesarean section to avoid special complications of incarceration should be developed. The incarcerated gravid uterus is recognized as being in a state of uterine retroflexion by pelvic examination or transvaginal ultrasonography in early pregnancy. As gestational weeks increase, the degree of retroflexion increases, resulting in embedding of the uterine fundus in the Douglas' pouch at the end of pregnancy ( Fig. 8 ). 4 When there is elongation and elevation of the cervix due to cervical myoma in the posterior wall of the uterus or myoma in the lower uterine segment, cervical findings are similar to those in cases with an incarcerated gravid uterus ( Fig. 9 ). 4 Incarcerated uterus. Pelvic examination readily leads to a diagnosis of incarcerated gravid uterus because this examination yields characteristic findings. However, it is likely to be overlooked on ultrasonography alone. Because the cervix and uterine wall are thin at the end of pregnancy, it is difficult to diagnose retroflexion and incarceration of the uterus. The placenta attached to the posterior wall can be misdiagnosed as low-lying placenta or placenta previa. (Reproduced with permission from Takeda S. Cesarean section for incarcerated uterus and elongation of the uterine cervix. In: Hiramatsu Y, Konishi I, Sakuragi N, Takeda S, eds. Mastering the Essential Surgical Procedures OGS NOW, No.10. Massive Obstetric Hemorrhage: Critical Care for Intractable Bleeding and Definite Strategies of Hemostasis. (Japanese). Tokyo: Medical View; 2012: 154–159. Copyright © Medical View). Cervical elongation due to a myoma in the cervix. ( A ) In cases with cervical myoma in the posterior wall of the uterus or myoma in the lower uterine segment, the cervix is elongated. Therefore, myometrial incision at the usual level fails to reach the uterine cavity. In particular, in the case of performing a Pfannenstiel transverse incision, upward deviation of the lower uterine segment may be overlooked because the field of view in the peritoneal cavity is limited. Therefore, a transverse incision in the myometrium at the usual site fails to reach the amniotic cavity and the cervix is cut instead. ( B ) Incision at the usual site will result in cutting the cervix cross-sectionally or cutting into myoma in the posterior wall. (Reproduced with permission from Takeda S. Cesarean section for incarcerated uterus and elongation of the uterine cervix. In: Hiramatsu Y, Konishi I, Sakuragi N, Takeda S, eds. Mastering the Essential Surgical Procedures OGS NOW, No.10. Massive Obstetric Hemorrhage: Critical Care for Intractable Bleeding and Definite Strategies of Hemostasis. (Japanese). Tokyo: Medical View; 2012: 154–159. Copyright © Medical View). There are characteristic pelvic examination findings; the uterovaginal region is deviated anteriorly and superiorly to the pubis to an extreme degree. The protruded uterus and myoma are palpable in the Douglas' pouch. Colposcopy may fail to identify the uterovaginal region because it is deviated superiorly. It is common for the uterine fundus to be lower according to the gestational week, causing elongation of the bladder. If the incarcerated gravid uterus is not recognized until the end of pregnancy, pelvic examination may raise suspicion because the uterovaginal region is deviated anteriorly and superiorly to an extreme degree, although the cervix is difficult to identify on transabdominal ultrasonography. 7 On ultrasonography, the cervix is deviated anteriorly and superiorly, and the bladder appears to be suspended upward. 7 If incarcerated gravid uterus is suspected, magnetic resonance imaging can provide a definitive diagnosis based on the locations of the vagina, cervix, and bladder in the sagittal view. 8 It is important to determine the level of the skin incision and the site of the uterine incision wound in advance, by confirming the level of entry into the uterine cavity by ultrasonography prior to implementation of cesarean section. 3 4 Intraoperative ultrasonography is also useful. Cesarean section for an incarcerated uterus is basically the same as a routine cesarean section. However, to facilitate subsequent surgical manipulations, a longer than usual incision should be made to provide a large field of view. A subumbilical longitudinal midline skin incision is preferred because of a wider field of view. The possibility that the incision is cut upward to the navel during the operation should be assumed. When the cervix is elongated because of myoma, the positional relationships between the myoma, the cervix, the uterine body, and the round ligament of the uterus, and the bladder need to be confirmed. The bladder may be located extremely low but can also be elevated. The bladder should be palpated directly, and the urethral catheter be confirmed. If the bladder is extremely elevated, the upper end must be confirmed and separated. As for incision in the myometrium, the peritoneal reflection of the vesicouterine pouch cannot be the target, as would routinely be the case, and the boundary between the uterine body and isthmus is ambiguous. Therefore, we can rely only on preoperative ultrasonographic findings in such cases. The location of the uterine cavity should be confirmed by intraoperative ultrasonography, whenever possible. Because the vaginal wall and cervical canal in the final stages of pregnancy are thin, it may not be possible to confirm the location of the internal cervical os. It is also important to make sure of the distance to the uterine cavity. There is no need to strictly adhere to the use of deep transverse incision. If the cervix and the lower uterine segment are not distinguishable, longitudinal uterine incision is also a reasonable choice. Depending on the length of the elongated cervix, a longitudinal or transverse incision is made in the muscular layer near the umbilical region. When a transverse incision does not reach the amniotic cavity, the incision should be extended upward in the direction toward the uterine body in the manner of an inverted T-shaped or J-shaped incision. In cases of cephalic presentation, cephalic delivery should be performed by employing a mild Kristeller maneuver via the incision opening of the uterus. In cases of breech presentation, the trunk should be delivered according to the cesarean section in breech presentation procedure, followed by liberation of the arms and delivery of the fetal head. These procedures are the same as those in cesarean section in breech or transverse presentation, but the patency of the uterine os is more difficult to confirm. The myometrium should be sutured by placing simple interrupted sutures with absorbable thread. The second layer of suturing is performed for reinforcement. When an inverted T-shaped incision is made, the intersecting point should be joined firmly by Z or equivalent sutures. Suture and ligation should be carefully performed to obtain accurate matching of the layered planes to avoid piercing penetration of the myometrium. These procedures are the same as in those for cesarean section in breech or transverse presentation. When there is a cervical myoma ( Fig. 9 ), 4 outflow of lochia from the cervical canal may be inhibited by the myoma. Therefore, frequent and meticulous follow-up observations for retention of lochia are necessary. Although incarcerated uterus may undergo reduction spontaneously after cesarean section, a careful follow-up is also necessary because there is concern about retention of lochia when there are no distinct changes in cervical elongation or incarceration status. If there is bleeding or difficulty in delivering the fetus, it is important to secure the field of view. If the skin incision is narrow, and the field of view is insufficient, the incision should be extended. When the Pfannenstiel transverse incision is performed, the rectus abdominis muscle may be cut unilaterally or bilaterally (Maylard method), or the rectus abdominis fascia can be cut in a T shape toward the pubis or separated and cut in an inverted T shape. Alternatively, both of these procedures may be performed to secure the field of view. After delivery of the fetus, it is difficult to move the uterus outside the body because of adhesions to the Douglas pouch, which makes suturing difficult. The bleeding point should be clamped with serrated forceps, and the positional relationships between the cesarean section wound, vagina, cervix, body of the uterus, and surrounding organs including the bladder, ureter, uterine artery and vein, and the cardinal ligament need to be ascertained and well understood. Bleeding from the paravaginal tissue and cardinal ligament is an important issue. If the bladder is located low or separated sufficiently, injury to the bladder and ureter is avoidable. If the lumen of the cervical canal is obscure, orientation can be obtained by insertion of the fingers or forceps from the vagina or by insertion of a urethral balloon catheter into the cervical canal. Even when the cervical canal is cut cross-sectionally, a catheter should be passed through it, and the upper and lower cut ends can then be sutured by simple interrupted suture with 2–0 or 1–0 absorbable thread. Attention should be paid to possible rupturing of the suture after repair, and it should thus be ensured that a drain is inserted in the vicinity of the sutured portion. If abdominal closure is performed without recognizing the presence of injury to the bladder or ureter, an echo free space will appear in the peritoneal cavity alongside an increase in blood urea nitrogen and creatinine within a few days. Patients may complain of mild symptoms such as a vague feeling of discomfort and lassitude, or may sometimes be minimally symptomatic. There may also be leukocytosis and a slight increase in C-reactive protein. Caution should be exercised regarding massive transfusion-related hyperpotassemia, hepatic dysfunction, hemolytic reaction, etc.