Biomedical subjects
Publications and source records attributed to R M Soderstrom.
Because most diagnostic hysteroscopes take only a few minutes, the experienced hysteroscopist generally prefers to use CO2 distention. For extensive operative procedures, especially submucous myomectomy, glycine or sorbitol usually are chosen.
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Although electrosurgery has been employed for decades, few surgeons have received formal training in its proper use. The erroneous belief that electrosurgery techniques increase scar formation or impair healing processes led surgeons to use other methods to deliver energy to the living cell. At the cellular level, 1 watt is 1 watt. Knowing how to calculate and administer this amount of energy is the challenge. Laser technology fostered the development of improved electrogenerators and accessories that are easier to understand and control. The use of digital reader boards, displayed in watts rather than an arbitrary dial setting, is one example. A good electrosurgical system, with proper accessory electrodes, costs only 10% of the price of the average laser. For hysteroscopic resectoscopy procedures, a thorough knowledge and appreciation of the physics of electrosurgery is a basic requirement. In the future, I hope the power density and wattage delivered at the electrode tip will be displayed easily for surgeons using the resectoscope. One day, we may have a "laser-electrode" system to meet all our needs.
The "drip-stop-coagulate" technique used during microsurgery is tedious and, at times, frustrating when electrolyte-rich solutions are used as an irrigant. Glycine, a nonelectrolyte solution, allows the gynecologist to apply electrosurgical energy in a fluid medium; lactated Ringer's solution, the irrigant frequently used by microsurgeons, will not. When, during microsurgery, glycine is used in place of lactated Ringer's solution, the origin of the bleeding site can be easily isolated and coagulated during irrigation, assisting the surgeon in precise and complete hemostasis.
Though electrosurgery has been with us for decades, few surgeons have received formal training in its potential uses. The erroneous belief that electrosurgery techniques increase scar formation or impair healing processes, has led surgeons to other methods to deliver energy to the living cell. A watt, is a watt, is a watt--knowing how to calculate and administer that energy is the challenge. Fig. 4. Laser technology has forced the bioelectrical engineers to develop improved electrogenerators and accessories that are easier to understand and control. The use of digital reader boards, displayed in watts rather than an arbitrary dial setting is one example. A current flow meter for bipolar forceps will now tell the surgeon when all of the tissue has been desiccated. Soon I hope the power density and wattage delivered at the electrode tip will be easily displayed for the gynecologic surgeons. Who knows, one day we may have a "laser-electrode" system to meet all of our needs.
The increasing use of laparoscopy as a therapeutic method mandates a reappraisal of the risks involved. Complications frequently described include injuries to the large and small bowels, bladder, and blood vessels. The world literature reports only eight cases of ureteral injury at laparoscopy. In this report, we present five additional cases of ureteral injury occurring at laparoscopy, in addition to a summary of those previously reported. Patients tend to present in the early postoperative period (48-72 hours) with low back pain, abdominal pain, leukocytosis, and peritonitis. The diagnosis should be made by intravenous pyelography; if possible, the injury should be stented by either the retrograde or percutaneous route. The injuries, except for one apparent trocar injury, involved the use of electrocoagulation, both unipolar and bipolar. The injuries occurred most commonly near the uterosacral ligaments. In 38% (five of 13) of the cases, the laparoscopy was performed for treatment of endometriosis. Three of the 13 patients eventually lost renal function of the affected side; two of these underwent a nephrectomy. Because visualization of the ureter near the cervix at the time of laparoscopy is difficult, especially in the presence of disease, laparoscopic procedures in this area must be carried out with caution.
Though electrosurgery has been with us for decades, few surgeons have received formal training in its potential uses. The erroneous belief that electrosurgery techniques increase scar formation or impair healing processes, has led surgeons to other methods to deliver energy to the living cell. At the cellular level, a watt, is a watt, is a watt -- knowing how to calculate and administer that energy is the challenge. Laser technology has forced the bioelectrical engineers to develop improved electrogenerators and accessories that are easier to understand and control. The use of digital reader boards, displayed in watts rather than an arbitrary dial setting is one example. A current flow meter for bipolar forceps will now tell the surgeon when all of the tissue has been desiccated. Soon I hope the power density and wattage delivered at the electrode tip will be easily displayed for the biogynecologic surgeons. Who knows, one day we may have a "laser-electrode" system to meet all of our needs.
There is growing interest in using the urologic resectoscope for endometrial ablation, but the actual depth of tissue destruction is unknown. A preliminary in vitro study measured the depth of visible coagulation produced when various waveforms of high-frequency current were applied to tissue using the "rollerball" electrode of the resectoscope. Tissue necrosis caused by high-frequency electrical energy is not immediately apparent: several days must elapse before the true extent of the damage can be seen. To study it, the uterus from a woman who was planning to undergo a hysterectomy was treated with the resectoscope four days prior to surgery. The depth of tissue destruction caused by 19 and 59 W of "cutting" current and by 28 and 57 W of "coagulating" current was 1.5, 2.7, 6.1 and 1.8 mm, respectively. A second patient underwent a hysterectomy 48 hours after resectoscopic endometrial ablation. There was no endometrium remaining, and coagulation extended 2-3 mm into the myometrium. Visual effects on the surface do not predict actual tissue destruction, so further in vivo studies will be necessary in order to obtain consistent clinical results.
Many bipolar sterilization failures have occurred because of incomplete desiccation of the endosalpinx. This study compared the effect upon human fallopian tubes of different waveforms of electrical energy at advancing power settings. When the Valleylab SSE2-L generator was attached to the Kleppinger bipolar forceps, complete desiccation was confirmed with the power set at 25 W in a cutting waveform. Other waveforms (coagulation and blend) failed to complete the task at the same power setting. An inline current meter assures the operator that all the available energy is delivered. This information should help to reduce bipolar sterilization failures.
Legal questions will continue to increase with this popular operation because sterilization is the second most common procedure performed by gynecologists. Because of patient's expectation, the sterilization patient is particularly vulnerable to suggestions of malpractice after a complication or failure. Careful preoperative preparation of the patient and family; strict attention to equipment, education and outcome statistics; a conscientious concern when complications do occur will help to reduce sterilization legal claims. A thorough knowledge of the proper management after a complication must be part of the education process. Success following legal defense will be measured by a proper preparation, good records, and an impressive, knowledgeable expert witness.
In 1987, all practicing King County, Washington obstetricians (N = 181) were surveyed to determine the impact of rising malpractice premium rates and the threat of litigation on their obstetric practices. Six percent of respondents anticipated closing their practices over the next year, which means an additional 520 deliveries will have to be absorbed into existing obstetric practices. Of the 71% who increased their professional fees in 1986, 90% attributed the increase to higher malpractice premiums and increased risk of litigation.
One hundred forty-one women with tubal infertility, all of whom had been pregnant at least once before, were interviewed concerning their reproductive, contraceptive, medical, and sexual histories. Their responses were compared with those of a control group of 467 fertile women. A higher percentage of cases (13%) than controls (1%) had had a tubal pregnancy. From these percentages, we estimate that 92% of tubal infertility in women who have had a tubal pregnancy results from tubal pregnancy itself or factors that predisposed to its occurrence. We also estimate that approximately one-fifth of women who suffer a tubal pregnancy will subsequently be infertile because of a tubal abnormality. After controlling for the joint effects of several known risk factors for tubal pregnancy that independently predispose to infertility (eg, a history of pelvic inflammatory disease), the relative risk of tubal infertility associated with tubal pregnancy was 15.0 (95% confidence interval 5.2-43.6). However, because we had no sensitive indicator of antecedent tubal disease, we were extremely limited in our attempt to determine the extent to which this association was actually due to the consequences of the tubal pregnancy itself.
Recent reports of bipolar sterilization failures have questioned the compatibility of bipolar forceps used with different electrogenerators. Four different bipolar forceps were matched and mismatched with five generators and the electrocoagulation effect was studied by two physicians trained in the histologic evaluation of electrical injury. All bipolar systems, matched or mismatched, failed to coagulate the fallopian tube as completely as unipolar control--except for the matched Kleppinger system. Conversely, when mismatched with other generators the coagulation effect of the Kleppinger forceps fell far below that of other bipolar forceps--matched or mismatched. Each bipolar system should be compatible and its electrocoagulation effect studied before it is used for female sterilization.
As part of a case-control study of tubal ectopic pregnancy (TEP), we sought to evaluate the possible etiologic role of use of an intrauterine device (IUD) prior to conception. We interviewed 155 women who had a tubal ectopic pregnancy treated at one of five Seattle, Washington hospitals between 1975-79 regarding their reproductive, contraceptive, and medical histories; 456 women who delivered a baby in King County during the same period were identified from vital records and interviewed as controls. An elevated risk of TEP was detected among former users of the Dalkon Shield (adjusted OR = 2.5; 95% CI = 1.3-4.7). Women who had used other IUDs did not have an excess risk of TEP.
To say that a sterilization failure rate is expected does not answer why. Forty-seven cases of repeat sterilization have undergone such surgical and pathologic scrutiny. Resection methods failed most frequently because of spontaneous reanastomosis or fistula formation. Fimbriectomy was particularly vulnerable to reanastomosis because the fimbria ovarica was not removed. Mechanical devices failed when the device was defective, placed improperly, or placed in an improper location. Tissue damage was evident but incomplete when the bipolar electrocoagulation method failures were reviewed, and the endosalpinx remained viable. Unipolar method injuries, in contrast, were complete; they failed by fistula formation. Thus bipolar method failures may occur because of the limited range of electrical power available when using bipolar generators. Some sterilization failures are preventable, but many are not. When medicolegal questions arise, these findings may help answer the question, Why?
Women who use an intrauterine device (IUD) are at increased risk of acute pelvic inflammatory disease, but the relation of the IUD to subsequent infertility is not established. We interviewed 159 nulligravid women with tubal infertility to determine their prior use of an IUD. Their responses were compared with those of a matched group who conceived their first child at the time the infertile women started trying to become pregnant. The risk of primary tubal infertility in women who had ever used an IUD was 2.6 times that in women who had never used one (95 per cent confidence interval, 1.3 to 5.2). The observed difference between cases and controls was not uniform for different types of IUD. The relative risk associated with use of a Dalkon Shield was 6.8 (1.8 to 25.2), and that associated with use of either a Lippes Loop or Saf-T Coil IUD was 3.2 (0.9 to 12.0). The smallest elevation in risk was found among users of copper-containing IUDs (relative risk, 1.9 [0.9 to 4.0] for all women who had ever used a copper-containing IUD). The relative risk for women who used only a copper-containing IUD was 1.3 (0.6 to 3.0). We conclude that use of the Dalkon Shield (and possibly of plastic IUDs other than those that contain copper) can lead to infertility in nulligravid women.
Bowel injuries during laparoscopy can result from either electrical damage or direct trauma. When electrocoagulation is used with laparoscopy, it is frequently assumed that any bowel injury is from that source. That assumption might not be accurate. In animal studies we evaluated the histologic characteristics of both electrical and traumatic bowel injuries. A consistent difference in injury pattern, both gross and microscopic, was noted. With a high degree of accuracy, those histologic and gross characteristics can be used to distinguish traumatic from electrical injuries following operative laparoscopy.