Isthmic ectopic pregnancy: segmental resection as the treatment of choice

Vol. 44, No.3, September 1985 PrinfRd in U.S.A.

FERTILITY AND STERILITY Copyright' 1985 The American Fertility Society

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Isthmic ectopic pregnancy: segmental resection as the treatment of choice

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Alan H. DeCherney, M,D,* Stephen P. Boyers, M.D.

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Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut

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We reviewed the records of 12 patients who were admitted to Yale-New Haven Hospital between February 1979 and January 1983 with the diagnosis of isthmic ectopic pregnancy. All pregnancies were unruptured. Two patients were managed by salpingectomy. Ten patients were treated conservatively. Of the women managed by conservative surgery, four had a linear salpingostomy and none of the four conceived. Three of these four patients demonstrated occlusion of the operated tube by hysterosalpingogram (HSG). The other six patients were managed by segmental resection and delayed microsurgical anastomosis. Four of the six patients conceived . Three pregnancies were intrauterine and one was an ectopic pregnancy in the conserved tube. Three patients conceived before an HSG could be done. The remaining three patients had HSGs 3 to 4 months after anastomosis, and the operated tube was patent in all three. From these data and a review of the literature, we conclude that segmental resection with either immediate or delayed anastomosis appears preferable to linear salpingostomy for the conservative management of unruptured isthmic ectopic pregnancy. Fertil Steril44:307, 1985

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Ectopic pregnancy in the isthmic portion of the fallopian tube is uncommon, comprising 5% to 15% of all tubal ectopic pregnancies. I - 5 Ampullary and infundibular ectopic pregnancies, residing in the distal two thirds of the tube, are much more common, accounting for 85% to 95% of all tubal ectopic pregnancies. The value of tubal conservation has been well established, particularly for ampullary ectopic pregnancies, in which a simple linear salpingostomy appears to be the surgical procedure of choice. 6 For isthmic ectopic

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pregnancies the optimum surgical approach has not been clearly defined. Both linear salpingostomy and segmental resection have been described. It appears that segmental resection with either primary or secondary anastomosis is preferable to linear salpingostomy when an unruptured ectopic pregnancy is found in the isthmic portion of the fallopian tube. MATERIALS AND METHODS

Received February 26, 1985; revised and accepted May 17, 1985. *Reprint requests: Alan H. DeCherney, M.D., Department of Obstetrics and Gynecology, Yale University School ofMedicine, 333 Cedar Street, P.O. Box 3333, New Haven, Connecticut 06510.

The records of 248 patients who were admitted to Yale-New Haven Hospital between February 1979 and January 1983 with the diagnosis of ectopic pregnancy were reviewed. Twelve patients (4.8%) had isthmic ectopic pregnancies. All pregnancies were unruptured. Two patients were managed by salpingectomy. Ten patients were

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treated conservatively. All were young, surgically stable, and anxious to preserve their fertility. Four underwent linear salpingostomies; six had segmental resections. The linear salpingostomies were accomplished by techniques described previously,6,7 three by laparotomy and one by laparoscopy. All were left open, to close secondarily. Segmental resections were carried out by elevation of the maximal bulge in the isthmic portion of the fallopian tube and then excision of the ectopic pregnancy as described by Gomel. 8 The tubal ends proximal and distal to the ectopic site were ligated with 2-0 Prolene (Ethicon, Somerville, NJ) suture. In all cases microsurgical technique was employed without magnification; tissues were handled gently and were kept moist by continuous irrigation. Bleeding was· controlled by pinpoint microcautery. All patients received ampicillin prophylactically, 500 mg intravenously during the procedure and every 6 hours for 4 days postoperatively. Two hundred milliliters of 32% dextran 70 (Hyskon, Pharmacia Laboratories, Piscataway, NJ) was placed in the abdomen at the conclusion of each case. In the segmental resection group, patients were readmitted 3 to 6 months later for a secondary tubal anastomosis. The repair was accomplished by microsurgical technique in two layers with the use of the operating microscope. Muscularis was reapproximated with four to six i~terrupted sutures of 8-0 or 9-0 Vicryl (Ethicon). Serosa was closed with a continuous suture of 7-0 Vicryl. The tubal lumen was identified with a #2 nylon stent, which was removed immediately after the anastomosis was completed. Again, all patients received ampicillin prophylactically, 500 mg intravenously 6 and 3 hours preoperatively and every 6 hours for 4 days postoperatively. Dexamethasone, 20 mg and promethazine, 25 mg were given intravenously 6 and 3 hours preoperatively and every 4 hours for 12

doses postoperatively. Two hundred milliliters of Hyskon was placed into the abdomen at the completion of each case. Before anastomosis, all patients in the segmental resection group contracepted with barrier methods. Hysterosalpingograms (HSGs) were done 4 to 6 months after surgery in both the salpingostomy and segmental resection groups unless pregnancy intervened. Follow-up occurred for 100% of these 12 patients, ranging from 5 to 14 months.

RESULTS SALPINGECTOMY GROUP

Two patients, one 29 and one 36 years of age, were treated by salpingectomy. Both were multiparous and had at least one living child in addition to a previous tubal ectopic pregnancy. One did not desire further fertility. In both patients, the contralateral tube was absent. LINEAR SALPINGOSTOMY GROUP

Four patients were treated by linear salpingostomy, three at pelvic laparotomy and one at laparoscopy. Demographic data, operative findings, and outcomes are tabulated in Table 1. Mean age was 25 years. Three of the four patients were nulliparous. Each had a contralateral tube present; in three patients the contralateral tube appeared normal and in one it was clubbed and occluded distally. At 3 to 4 months postoperatively, three patients had HSGs; the fourth patient declined. Each of the three patients showed occlusion of the operated tube. The contralateral tube was patent in two and occluded in one of the patients. All four patients resumed regular unprotected intercourse with a desire to conceive. Follow-up has been 5 to 14 months. None of these four has achieved a pregnancy.

Table 1. Linear Salpingostomy Group Patient

Age

Gravida

Para

Status of contralateral tube

Operated tube

HSG Contralateral tube

Pregnancy

yr

29 2' 24 27

S. L.

T.F. S. S. S. J.a

1 1

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2 2

1

o

Normal Normal Clubbed Normal

Closed

Open

Closed Closed

Closed Open

No No No No

aLaparoscopy.

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SEGMENTAL RESECTION GROUP

Six patients were treated by segmental resection with delayed anastomosis 3 to 6 months after ectopic pregnancy. Table 2 outlines demographic data, operative findings, and outcomes for this group. Mean age was 34 years. All six patients were nulliparous. Five patients had a contralateral tube present; one had had a previous salpingectomy. Four of the five contralateral tubes appeared normal; one tube had peritubal adhesions. Three patients conceived before hysterosalpingography could be done. The remaining three patients had HSGs 3 to 4 months after anastomosis. The operated tube was patent in all three patients. The contralateral tube was patent in two and· absent in.one of the patients. One of these patients also conceived; two remain infertile. Of the four fertile patients, three had normal intrauterine pregnancies and term deliveries; one patient had a repeat ectopic pregnancy in the operated tube. In summary, we have reported outcomes, in terms of pregnancy and HSG findings, of 12 patients operated on for unruptured isthmic ectopic pregnancies. Two patients were treated by salpingectomy, whereas ten patients were treated conservatively. Four patients were managed by linear salpingostomy and none conceived. Three of the four patients had an HSG, and all three .x-rays demonstrated occlusion of the operated tube. Six patients were managed by segmental resection and delayed microsurgical anastomosis. Four of the six patients conceived; three pregnancies were intrauterine pregnancies and one was an ectopic pregnancy in the conserved tube. All three patients who underwent HSG demonstrated patency of the operated tube. DISCUSSION

Modern surgery for tubal ectopic pregnancy has

two goals: (1) the prevention of mortality and morbidity; and (2) when desired, the preservation of fertility. The dictum "once an ectopic, always an ectopic" has been proven false, and the value of conservative surgery is well established. At the same time, the opportunity for conservative tubal surgery is much greater. With a high index of sllspicionand rapid, sensitive radioimmunoassays for serum l3-human chorionic gonadotropin coupled with high resolution pelvic ultrasound and early laparoscopy, the majority of tubal ectopic pregnancies can be discovered before rupture. The problem today is increasingly one of therapy, not diagnosis. Because most tubal ectopic pregnancies occur in the distal two thirds of the fallopian tube, conservative surgery for ampullary ectopic pregnancy has been most thoroughly studied. There have been at least 71 cases reported where conservative surgery forunruptured ampullary ectopic pregnancy was accomplished by linear salpingostomy in women with absent or occluded contralateral tubes. Sixty-one percent eventually established an intrauterine pregnancy and 11% had repeat ectopic pregnancies. In our study of 15 patients, the intrauterine pregnancy rate was 53% and 20% had another ectopic pregnancy.6 Morbidity with tubal conservation has been rare , although postoperative bleeding, requiring a second laparotomy, has been reported. 9 • 10 In contrast, there are relatively little data concerning the optimum conservative approach to ectopic pregnancies in the isthmic portion of the fallopian tube. Isthmic ectopic pregnancies are uncommon and unruptured isthmic pregnancies even more so, supporting the suggestion that the rate of rupture at diagnosis increases as the ectopic ·pregnancy site moves proximally.ll Many reports of the conservative management of tubal ectopic pregnancies do not clearly distinguish isthmicfromampullary sites and lump successful

Table. 2. Segmental Resection Group :Patient

Age

M.L. J.J. F.S.

33 36 36 35 31 34

Gravida

Para

Status of contralateral tube

1 1 1 2 1 1

0 0 0 ·0 0 0

Normal Adhesions Normal Absent Normal Normal

Operated . tube

HSG Contralateral tube

·Pregnancy

yr

C.P. M.S. A.C.

Open Open Open

Open Absent Open

Yes Yes Yes No No

Yes a

aRepeat· ectopic, ipsilateral. Vol. 44, No.3, September 1985

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outcomes without regard to either site or technique of tubal conservation. Others fail to follow fertility at all or neglect a description of the contralateral tube. Shinfeld and Reedy12 reported prophylactic mesosalpingeal vessel ligation in 39 patients with conservatively operated unruptured tubal ectopic pregnancies; 32 were ampullary and 7 were isthmic. Twelve occurred in the sole remaining tube; in 27, the contralateral tube was present. All but three were managed by either linear salpingostomy or expression. Fourteen conceived, but outcome was not related to ectopic pregnancy site. Valle and Lifchez 13 performed linear salpingostomies in 13 patients, all with absent contralateral tubes. Ten ectopic pregnancies were ampullary, one was isthmic, and two were isthmicoampullary. Eleven patients subsequently tried to conceive; and all 11 carried at least one intrauterine pregnancy to term, including all 3 with isthmic or isthmicoampullary sites. Langer and colleagues 14 included only two isthmic ectopic pregnancies among their 57 conservatively operated cases, and it is again not clear whether either patient was among those who later conceived or whether they had contralateral tubes. Taylor and Cumming 15 reported six cases of unruptured tubal ectopic pregnancies managed by minilaparotomy with segmental resection. Four ectopic pregnancies were isthmic and two were ampullary, but no follow-up was reported. Finally, Swolin 16 reported 14 cases of ectopic pregnancy managed by resection of the pregnancy site followed by simple approximation of the mesosalpinx, apposing proximal and distal tubal lumina without formal anastomosis. Both pure isthmic and isthmicoampullary ectopic pregnancies were included. Outcome was judged only by HSG, which showed 6 of 13 operated tubes patent. Follow-up did not include pregnancy rate, nor was there information as to the status of the contralateral tube. In a follow-up study by Swolin and Fall,17 there was an intrauterine pregnancy rate of 24% and an ectopic pregnancy rate of 14% in 42 patients managed by segmental resection, but the status of the contralateral tube was not reported. Three groups of investigators S, IS-20 have reported more complete data, all supporting the effectiveness of segmental resection for isthmic or isthmicoampullary ectopic pregnancy. Stangel and Gomel 1s operated on seven patients with unruptured isthmic ectopic pregnancies; all had segmental resection and immediate anastomosis.

All seven patients had patent operated tubes found at subsequent HSG. Only two patients tried to conceive. Both women carried intrauterine pregnancies to term. In each of them, the operated tube was the sole tube, which provides clear evidence that tubal conservation was directly responsible for success. Stangel and Reyniak 19 subsequently reported postoperative tubal patency found at HSG in 100% of 11 patients managed in this fashion. There was no additional information on pregnancy attempts or outcome. Gomel s reported nine patients with unruptured isthmic or isthmicoampullary ectopic pregnancies in their sole remaining tube, each of whom were treated conservatively by segmental resection and delayed anastomosis. In seven women the contralateral tube was absent and in two it was occluded. Six of the nine patients subsequently conceived. Five women delivered at term and one had a repeat ectopic pregnancy. Finally, Siegler et al. 20 reported that Sayed completed eight conservative operations for unruptured ectopic pregnancy, with segmental resection and immediate anastomosis. It was not specified whether all ectopic pregnancies were purely isthmic or included isthmicoampullary sites. Six of the eight women conceived, all having intrauterine pregnancies with no repeat ectopic pregnancies. To our knowledge, Sayed's series has not been published and the status of the contralateral tube is unknown. Table 3 summarizes our information on conservative surgery for isthmic ectopic pregnancy. There are important anatomic differences between the isthmic and ampullary portions of the fallopian tube that may explain why segmental resection appears best suited to isthmic ectopic pregnancy and linear salpingostomy to ectopic pregnancy in the ampulla. The ampulla is the longest portion of the tube, varying from 5 to 8 cm, and has a lumen, which is 1 to 2 mm in diameter at its narrowest proximal portion, expanding distally to as wide as 2 cm. Tubal endothelium here is thrown into complex folds, and ciliated cells are prominent. This large lumen is surrounded by a loose mantle of adventitia and a modest layer of smooth muscle. In contrast, the isthmus is much shorter, beginning at the uterotubal junction and extending distally for 2 to 3 cm. It contains the narrowest lumen, averaging only 0.4 mm, and the thickest musculature of any portion of the extrauterine tube. An unruptured ectopic pregnancy in either area distorts normal anatomy but, contrary to popular notion, is not

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Table 3. Conservative Surgery for Isthmic Ectopic Pregnancy Author

Schinfeld and Reedy12 Valle and Lifchez 13 Langer et al. 14 Taylor and Cumming15 Swolin 16 Swolin and Fall 17 Stangel et aUs, 19 Gomel s Siegler et al. 20 Present study Present study

No. of cases

7 3b 2

4

14c 42 c 11 9c 8c 6 4

Operative method

Contralateral tube

Salpingostomy Salpingostomy Salpingostomy Segmental resection

Unspecified Absent (3) Unspecified Unspecified

Segmental Segmental Segmental Segmental Segmental Segmental

Unspecified Unspecified Absent (2) Absent (9) Unspecified Normal (4) Absent (1) Adhesions (1) Normal (3) Clubbed (1)

resection resection resection resection resection resection

Salpingostomy

Outcome

Iupa

Ectopic

3

0

6

3/3

10 2d 5 6 3

0/3

0

0

HSG

6/13 11/11

1 0 1

aIUP, intrauterine pregnancy. bOne pure isthmic, two isthmicoampullary. cIncludes isthmicoampullary. dBoth with absent contralateral tubes.

confined to the tubal lumen. Budowick et al. 21 have shown that, although implantation occurs on the luminal surface, a growing gestation rapidly penetrates the muscular wall, subsequent growth being primarily extraluminal. What appears to be an unruptured isthmic ectopic pregnancy within a dilated isthmic lumen is in reality a narrow isthmus with destruction of surrounding muscularis. Simple linear salpingostomy without resection of damaged tube usually results in isthmic obstruction. Segmental resection removes the damaged isthmus, and the thick muscularis and simple endothelium facilitate anastomosis. Experience with sterilization reversal has established isthmic-isthmic anastomosis as the most successful for similar reasons,22 and experimental microsurgery in the rabbit indicates that the isthmic portion of the fallopian tube is the least essential for fertility23, 24 and hence an ideal site from which to resect tube. In contrast, the large-diameter ampullary lumen is unlikely to stenose after salpingostomy, and the ampullary tube is a much less satisfactory site for segmental resection. The complex infolding of ampullary endothelium and the thin muscularis make anastomosis more difficult, and ampullary length and surface area of ciliated endothelium may be more critical to fertility. For these anatomic reasons, segmental resection and anastomosis should be encouraged in the isthmus Vol. 44, No.3, September 1985

and avoided in the ampulla, except in the proximal ampulla, where the isthmicoampullary lumen is relatively narrow and muscularis prominent. Our data comparing outcomes of unruptured isthmic ectopic pregnancies managed by linear salpingostomy or segmental resection with delayed anastomosis indicate poor results with salpingostomy and good patency and pregnancy rates with segmental resection. There are no randomized trials of one technique versus the other, but the existing literature supports our findings. An added advantage of segmental resection is its applicability to even ruptured isthmic ectopic pregnancies. Indeed, in the event of tubal rupture, segmental resection in either the proximal or distal tube may be preferable to salpingectomy even if the contralateral tube is normal, providing the patient is surgically stable and desires further fertility. Anastomosis should probably be delayed, and may never be necessary if the contralateral tube is patent. Should pregnancy not occur or the contralateral tube be lost, the conserved tube would be available for anastomosis. In conclusion, segmental resection with either immediate or delayed anastomosis appears preferable to linear salpingostomy for the conservative management of unruptured isthmic ectopic pregnancy. Although linear salpingostomy has been successful in ampullary ectopic pregnancy,_ DeCherney and Boyers Isthmic ectopic pregnancy

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the distinct anatomic differences between ampulla and isthmus make linear salpingostomy a poor choice in the isthmic tube.

REFERENCES 1. Breen JL: A 21-year survey of 654 ectopic pregnancies. Am J Obstet Gynecol 106:1004, 1970 2. Hallatt JG: Repeat ectopic pregnancy: a study of 123 consecutive cases. Am J Obstet Gynecol 122:520, 1975 3. Powers DN: Ectopic pregnancy: a five-year experience. South Med J 73:1012, 1980 4. Gonzalez FA, Waxman M: Ectopic pregnancy: a retrospective study of 501 consecutive patients. Diagn Gynecol Obstet 3:181, 1981 5. Sherman D, Langer R, Sadovsky G, Bukovsky I, Caspi E: Improved fertility following ectopic pregnancy. Fertil Steril 37:497,1982 6. DeCherney AH, Maheaux R, Naftolin F: Salpingostomy for ectopic pregnancy in the sole patent oviduct: reproductive outcome. Fertil Steril 37:619, 1982 7. Bruhat MA, Manhes H, Mage G, Pouly JL: Treatment of ectopic pregnancy by means of laparoscopy. Fertil Steril 33:411, 1980 8. Gomel V: Conservative surgical treatment of tubal pregnancy. In Microsurgery in Female Infertility, Edited by V Gomel. Boston, Little, Brown & Co., 1983, p 253 9. Kelly RW, Martin SA, Strickler RC: Delayed hemorrhage in conservative surgery for ectopic pregnancy. Am J Obstet Gynecol 133:225, 1979 10. Jarrell FJ: Delayed hemorrhage following conservative surgery for tubal ectopic pregnancy: prevention and early detection. Can J Surg 27:251, 1984 11. Pagano R: Ectopic pregnancy: a seven-year survey. Med J Aust 2:586, 1981 12. Schinfeld JS, Reedy G: Mesosalpingeal vessel ligation for conservative treatment of ectopic pregnancy. J Reprod . Med 28:823, 1983

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13. Valle JA, Lifchez AS: Reproductive outcome following conservative surgery for tubal pregnancy in women with a single fallopian tube. Fertil Steril 39:316, 1983 14. Langer R, Bukovsky I, Herman A, Sherman D, Sadovsky G, Caspi E: Conservative surgery for tubal pregnancy. Fertil Steril 38:427, 1982 15. Taylor PJ, Cumming DC: Combined laparoscopy and minilaparotomy in the management of unruptured tubal pregnancy: a preliminary report. Fertil Steril 32:521, 1979 16. Swolin K: Die einwirkung von grossen intraperitonealen dosen glukokortikoids auf die bildung von postoperativen adhasionen. Acta Obstet Gynecol Scand 46:204, 1967 17. Swolin K, Fall M: Ectopic pregnancy: recurrence, postoperative fertility and aspects of treatment based on 182 patients. Acta Eur Fertil 3:147, 1972 18. Stangel JJ, Gomel V: Techniques in conservative surgery for tubal gestation. Clin Obstet Gynecol 23:1221, 1980 19. Stangel JJ, Reyniak JV: Conservative techniques for the management of tubal pregna!lcies. In Principles of Microsurgical Techniques in Infertility, Edited by JV Reyniak, NH Lauersen. New York, Plenum Publishers, 1982, p 207 20. Siegler AM, Wang CF, WestoffC: Management ofunruptured tubal pregnancy. Obstet Gynecol Surv 36:599, 1981 21. Budowick M, Johnson TRB Jr, Genadry R, Parmley TH, Woodruff JD: The histopathology of the developing tubal ectopic pregnancy. Fertil Steril 34:169, 1980 22. Henderson SR: The reversibility of female sterilization with the use of microsurgery: a report on 102 patients with more than one year offollow-up. Am J Obstet Gynecol 149:57, 1984 23. McComb P, Gomel V: The influence of fallopian tube length on fertility in the rabbit. Fertil Steril 31:673, 1979 24. Gomel V, McComb P: Microsurgery in reproductive physiology. In Microsurgery in Female Infertility, Edited by V Gomel. Boston, Little, Brown & Co., 1983, p 29 >

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