These conditions may be prevented in many ways. The tissues included in the ligature are not always free from infective organisms, especially the Fallopian tube, which is usually included in the ligature, and this structure, especially in cases where oöphorectomy is performed for inflammatory diseases, often contains septic microbes; this endangers the ligature and leads to the formation of pus, with its complications, sloughing of the pedicle and abscess. The tissues may be healthy and aseptic, but the ligature may have been imperfectly sterilized, or become contaminated by assistants, or even by the hands of the surgeon during its application.
The operation may have been conducted aseptically and the tissues be healthy, but the ligature becomes infected by the admission of air as a result of drainage, or implication of the bowel or bladder.
I made a careful study of the fate of silk sutures employed in pelvic surgery extending over many years, and came to the conclusion that, even under favourable conditions, silk ligatures disappear very slowly. The silk used to secure an ovarian pedicle may, in very favourable circumstances, disappear in twelve months, but the knots require nearly double that time. The piece of silk which encircles the Fallopian tube is apt to behave in a curious way; in 1898 I removed an ovarian cyst the size of a fist, and tied its slender pedicle with thin silk. Although the recovery was uneventful, the patient complained during many weeks of cramp-like pains on the side from which the cyst was removed. These pains gradually subsided, and ten months later, during menstruation, the patient noticed on the napkin a tiny loop of silk, which she saved. This was the loop of silk which secured the Fallopian tube; it had ulcerated into the tube and been conducted into the uterus and escaped. I have since had a like condition, the loop making its appearance three weeks after an ovariotomy. It has been established by experiments on the long uterine cornu of rabbits, that an encircling ligature will ulcerate through, leaving the lumen of the cornu intact. Clinical observations regarding ligatures applied to Fallopian tubes in the performance of Cæsarean section for the purpose of preventing pregnancy prove that this is a useless measure (see [p. 71]), for these tubes in many instances have recovered their patency, and pregnancy has recurred. It is a fair inference that the ligature ulcerates into the lumen of the tube, which then heals behind it, without stricture of the canal. A similar condition of things sometimes arises after Cæsarean section, especially when the uterine incision is closed by two layers of sutures. Those sutures which involve the endometrium will ulcerate into the uterine cavity and cause irregular slight losses of blood until they escape.
Fig. 28. A Uterus in Sagittal Section. Showing silk ligatures which had been introduced in the operation of Cæsarean section four years previously. (Museum, Royal College of Surgeons.) Full size.
It is important to emphasize the fact that silk sutures in uterine tissue will, in some instances, remain unabsorbed for many years. A patient who had been submitted to Cæsarean section in 1903 came under my care four years afterwards for the removal of the tumour which caused obstruction; the sutures used to close the uterine incision were visible, and a microscopic examination showed that each silk suture was enclosed in a fibrous tissue sheath (Fig. 28).
The fact that silk sutures will resist absorption for such a long period has an important practical bearing, because so long as pathogenic micro-organisms are denied access they remain inert, but if any septic condition arises in their neighbourhood, and these sutures become involved, they will give rise to abscesses and sinuses as surely as if they had been buried but a few days.
Patients often suffer great distress and annoyance on account of abscesses and sinuses due to septic ligatures, and a sinus will persist as long as the ligature remains. Abscesses and sinuses resulting from troublesome ligatures may escape in many directions; the most common spot is at the lower angle of the abdominal incision; the rectum is another channel of escape, and also the bladder. When a ligature makes its way into the bladder it will set up cystitis and serve as a nucleus for a vesical calculus. In an unusual case recorded by Edebohls, double oöphorectomy was performed for uterine fibroids; a year later the ligature on the left side escaped through the vagina; six months later he performed abdominal hysterectomy. The vermiform appendix was adherent to the stump on the right side; it was removed, and a silk ligature tied in a complicated knot was found in it, making its way towards the cæcum.
On one occasion a woman, who had been submitted to subtotal hysterectomy in the Antipodes, suffered from frequent micturition and fœtid urine; she came under my care. On dilating the urethra, it was found that the cervical stump had ulcerated through the posterior wall of the bladder and projected freely into the vesical cavity, bristling with thick silk ligatures encrusted with phosphatic deposit. The ligatures were removed, the urine soon became acid, and the vesical discomfort quickly subsided, in spite of the anomalous position of the cervical stump.
Until surgeons fully realized the importance of thoroughly sterilizing the silk employed for the pedicles in ovariotomy, it was quite common for the silk loops to ulcerate through the bladder wall and set up cystitis.