Laparoscopic Surgery: A Systematic Review of Loop and Knot Security, Varying with the Suture and Sequences, Throws, Rotation and Destabilization of Half-Knots or Half-Hitches.

Surgical knots are sequences of half-knots (H) or half-hitches (S), defined by their number of throws, by an opposite or similar rotation compared with the previous one, and for half-hitches whether they are sliding (s) or blocking (b). Opposite rotation results in (more secure) symmetric (s) knots, similar rotation in asymmetric (a) knots, and changing the active and passive ends has the same effect as changing the rotation. Loop security is the force to keep tissue together after a first half-knot or sliding half-hitches. With polyfilament sutures, H2, H3, SSs, and SSsSsSs have a loop security of 10, 18, 28, and 48 Newton (N), respectively. With monofilament sutures, they are only 7, 16, 18, and 25 N. Since many knots can reorganize, the definition of knot security as the force at which the knot opens or the suture breaks should be replaced by the clinically more relevant percentage of clinically dangerous and insecure knots. Secure knots with polyfilament sutures require a minimum of four or five throws, but the risk of destabilization is high. With monofilament sutures, only two symmetric+4 asymmetric blocking half-hitches are secure. In conclusion, in gynecology and in open and laparoscopic surgery, half-hitch sequences are recommended because they are mandatory for monofilament sutures, adding flexibility for loop security with less risk of destabilization.

Effect of Diameter and Type of Suture on Knot and Loop Security.

The loop and knot securities of two polyfilament and two monofilament sutures of four diameters (3.0, 2.0, 0, 1) were evaluated with a tensiometer for four four-throw knots, known to be secure with a 2.0 polyfilament suture. Loop security of Monocryl 1 is low, being 14.7 ± 3.0 Newton (N) for a three-throw half-knot (H3) and 15.4 ± 2.4 N and 28.3 ± 10 N for two (SSs) and four (SSsSsSs) symmetrical sliding half-hitches. This is lower than 18, 24, and 46 N for similar knots with Vicryl. Polyfilament sutures have excellent knot security for all four diameters. Occasionally, some slide open with slightly lower knot security, especially for larger diameters, although this is not clinically problematic. Knot security of monofilament sutures was unpredictable for all four knots, especially for larger diameters, resulting in many clinically insecure knots. A secure monofilament knot requires a six-throw knot with two symmetrical sliding half-hitches or two symmetrical half-knots secured with four asymmetric blocking half-hitches. In conclusion, with polyfilament sutures, four- or five-throw half-knot or half-hitch sequences result in secure knots. For monofilament sutures, loop and knot security is much less, half-knot combinations should be avoided, and secure knots require six-throw knots with four asymmetric blocking half-hitches.

The 10 "Cardinal Sins" in the Clinical Diagnosis and Treatment of Endometriosis: A Bayesian Approach.

Evidence-based data for endometriosis management are limited. Experiments are excluded without adequate animal models. Data are limited to symptomatic women and occasional observations. Hormonal medical therapy cannot be blinded if recognised by the patient. Randomised controlled trials are not realistic for surgery, since endometriosis is a variable disease with low numbers. Each diagnosis and treatment is an experiment with an outcome, and experience is the means by which Bayesian updating, according to the past, takes place. If the experiences of many are similar, this holds more value than an opinion. The combined experience of a group of endometriosis surgeons was used to discuss problems in managing endometriosis. Considering endometriosis as several genetically/epigenetically different diseases is important for medical therapy. Imaging cannot exclude endometriosis, and diagnostic accuracy is limited for superficial lesions, deep lesions, and cystic corpora lutea. Surgery should not be avoided for emotional reasons. Shifting infertility treatment to IVF without considering fertility surgery is questionable. The concept of complete excision should be reconsidered. Surgeons should introduce quality control, and teaching should move to explain why this occurs. The perception of information has a personal bias. These are the major problems involved in managing endometriosis, as identified by the combined experience of the authors, who are endometriosis surgeons.

Segmental Rectum Resection for Deep Endometriosis and Excision Similarly Improve Sexual Function and Pain.

Segmental rectum resections for indications other than endometriosis were reported to result in up to 40% sexual dysfunctions. We, therefore, evaluated sexual function after low bowel resection (n = 33) for deep endometriosis in comparison with conservative excision (n = 23). Sexual function was evaluated with the FSFI-19 (Female Sexuality Functioning Index) and EHP 30 (Endometriosis Health Profile). The pain was evaluated with visual analogue scales. Linear excision and bowel resections improved FSFI, EHP 30, and postoperative pain comparably. By univariate analysis, a decreased sexual function was strongly associated with pain both before (p < 0.0001) and after surgery (p = 0.0012), age (p = 0.05), and duration of surgery (p = 0.023). By multivariate analysis (proc logistic), the FSFI after surgery was predicted only by FSFI before or EHP after surgery. No differences were found between low bowel segmental resection and a more conservative excision. In conclusion, improving pain after surgery can explain the improvement in sexual function. A deleterious effect of a bowel resection on sexual function was not observed for endometriosis. Sexual function in women with endometriosis can be evaluated using a simplified questionnaire such as FSFI-6.

Predictive Value of Ultrasound Imaging for Diagnosis and Surgery of Deep Endometriosis: A Systematic Review.

OBJECTIVE: To calculate the predictive value and thus the clinical usefulness of transvaginal ultrasound (US) imaging for the management of deep endometriosis, knowing that the positive predictive value (PPV) varies with the prevalence and probably with the volume and location of the disease. DATA SOURCES: After registration on PROSPERO (CRD42022366323), PubMed was searched for all reports describing the diagnostic accuracy of US imaging for deep endometriosis published between January 1, 2000, and October 20, 2022. METHODS OF STUDY SELECTION: The 536 articles on "endometriosis AND US And diagnosis" were hand searched, and 30 reports describing sensitivity and specificity of deep endometriosis were found. Besides sensitivity and specificity, the prevalence, localization, and size of deep endometriosis lesions were collected. TABULATION, INTEGRATION, AND RESULTS: Prevalences of deep endometriosis were reported only twice as 12% and 32% by ultrasonographers. In women undergoing surgery, prevalences vary between 40% and 100% because of the variable inclusion criteria. Specificity is higher than sensitivity for all locations: rectovaginal (97% [86-100] vs 74% [31-95], p = .0002), rectosigmoid (97% [63-100] vs 88% [37-97], p = .0082), vesicouterine (100% [97-100] vs 63% [22-100], p = .0021), and uterosacrals (91% [77-99] vs 68% [18-83], p = .0005). Notwithstanding improved equipment, accuracy did not vary over the last 20 years. Sensitivities or specificities have not been stratified by the size of the lesion, and thus, the lower detection limits are not known. In the absence of blinding, the usefulness for surgery could not be established. CONCLUSION: The reported sensitivities and specificities of transvaginal US are not only those of imaging but include symptoms and clinical examinations. In referral centers, the reported PPVs are high (94%-100%) given that prevalences are >10% and specificities are >95%. However, the extrapolation of the clinical use before surgical interventions should be considered with care, given that PPVs for smaller lesions and the lower detection limit are unknown and surgeons were not blinded to US results.

Peritoneal fluid progesterone and progesterone resistance in superficial endometriosis lesions.

Peritoneal fluid in ovulatory women is an ovarian exudate with higher estrogen and progesterone concentrations than in plasma. In the follicular phase, progesterone concentrations are as high as plasma concentrations in the luteal phase. After ovulation, estrogen and progesterone concentrations in the peritoneal fluid are 5-10 times higher than in plasma, both in women with and without endometriosis. The histologically proliferative aspect without secretory changes of most superficial subtle lesions is not compatible with the progesterone concentrations in the peritoneal fluid. Therefore, we have to postulate a strong progesterone resistance in these lesions. The mechanism is unclear and might be a peritoneal fluid effect in women with predisposing defects in the endometrium, or isolated endometrial glands with progesterone resistance, or subtle lesions originating from the basal endometrium: the latter hypothesis is attractive since in basal endometrium progesterone does not induce secretory changes while progesterone withdrawal, not occurring in peritoneal fluid, is required to resume mitotic activity and proliferation. Hormone concentrations in the peritoneal fluid are an important factor in understanding the medical therapy of endometriosis. The effect of oestro-progestin therapy on superficial endometriosis lesions seems to be a consequence of the decreased estrogen concentrations rather than a direct progestin effect. In conclusion, the peritoneal fluid, being a secretion product of the ovarian follicule, deserves more attention in the pathophysiology and treatment of endometriosis.

Pathogenesis Based Diagnosis and Treatment of Endometriosis.

Understanding the pathophysiology of endometriosis is changing our diagnosis and treatment. Endometriosis lesions are clones of specific cells, with variable characteristics as aromatase activity and progesterone resistance. Therefore the GE theory postulates GE incidents to start endometriosis, which thus is different from implanted endometrium. The subsequent growth in the specific environment of the peritoneal cavity is associated with angiogenesis, inflammation, immunologic changes and bleeding in the lesions causing fibrosis. Fibrosis will stop the growth and lesions look burnt out. The pain caused by endometriosis lesions is variable: some lesions are not painful while other lesions cause neuroinflammation at distance up to 28 mm. Diagnosis of endometriosis is made by laparoscopy, following an experience guided clinical decision, based on history, symptoms, clinical exam and imaging. Biochemical markers are not useful. For deep endometriosis, imaging is important before surgery, notwithstanding rather poor predictive values when confidence limits, the prevalence of the disease and the absence of stratification of lesions by size, localization and depth of infiltration, are considered. Surgery of endometriosis is based on recognition and excision. Since the surrounding fibrosis belongs to the body with limited infiltration by endometriosis, a rim of fibrosis can be left without safety margins. For deep endometriosis, this results in a conservative excision eventually with discoid excision or short bowel resections. For cystic ovarian endometriosis superficial destruction, if complete, should be sufficient. Understanding pathophysiology is important for the discussion of early intervention during adolescence. Considering neuroinflammation at distance, the indication to explore large somatic nerves should be reconsidered. Also, medical therapy of endometriosis has to be reconsidered since the variability of lesions results in a variable response, some lesions not requiring estrogens for growth and some being progesterone resistant. If the onset of endometriosis is driven by oxidative stress from retrograde menstruation and the peritoneal microbiome, medical therapy could prevent new lesions and becomes indicated after surgery.

Surgical management of endometriosis-associated pain.

Endometriosis and pelvic pain are associated. However, only half of the subtle and typical, and not all cystic and deep lesions are painful. The mechanism of the pain is explained by cyclical trauma and repair, an inflammatory reaction, activation of nociceptors up to 2.7 cm distance, painful adhesions and neural infiltration. The relationship between the severity of lesions and pain is variable. Diagnosis of the many causes requires laparoscopy and expertise. Imaging cannot exclude endometriosis. Surgical removal is the treatment of choice. Medical therapy without a diagnosis risks missing pathology and chronification of pain if not 100% effective. Indications and techniques of surgery are described as expert opinion since randomised controlled trials were not performed for ethical reasons, since not suited for multimorbidity while a control group is poorly accepted. Subtle endometriosis needs destruction since some cause pain or progress to more severe disease. Typical lesions need excision or vaporisation since depth can be misjudged by inspection. Painful cystic ovarian endometriosis needs adhesiolysis and either destruction of the lining or excision of the cyst wall, taking care to avoid ovarian damage. Cysts larger than 6 cm need a two-step technique or an ovariectomy. Excision of deep endometriosis is difficult and complication prone surgery involving bladder, ureter, and bowel surgery varying from excision and suturing, disc excision with a circular stapler and resection anastomosis. Completeness of excision, prevention of postoperative adhesions and recurrences of endometriosis, and the indication to explore large somatic nerves will be discussed.

Prevalence of Endometriosis and Peritoneal Pockets in Women with Infertility and/or Pelvic Pain.

OBJECTIVE: To evaluate the prevalence of endometriosis and peritoneal pockets and to analyze whether these pockets are associated with pain. METHODS: Analysis of prospectively registered data of all women undergoing laparoscopy for infertility or pelvic pain between 1988 and 2011 at KU Leuven University Hospital. RESULTS: Of 4497 women, 191 had 238 pockets, with a prevalence of 4.7% in women with infertility only, 4.9% in women with infertility and pelvic pain, and 3.5% in women with pelvic pain only (P = 0.045 for all infertility vs. pelvic pain only). Prevalence did not vary by age. Pockets were associated with endometriosis (P < 0.0001), which was found in 77% of women with pockets. Among women with infertility only, the prevalence of endometriosis was higher in women with pockets (P = 0.0001) than in women without. The prevalence of endometriosis was similar in women with infertility and pelvic pain or pelvic pain only. Pelvic pain as an indication for surgery was associated simultaneously (through logistic regression) with endometriosis (P < 0.0001) and pockets (P = 0.040). Pelvic pain severity was associated simultaneously with pockets (P = 0.0026) and the severity of subtle (P = 0.001), typical (P = 0.030), cystic ovarian (P = 0.051), and deep endometriosis (P < 0.0001). Pelvic pain severity was not associated with endometriosis in the pockets or the diameter or location of pockets. CONCLUSIONS: The prevalence of pockets was low, at between 3.5% and 5%. Women with infertility only and pockets had more endometriosis than women without. Severe pelvic pain and pelvic pain as an indication for surgery were associated with the presence of pockets as well as the presence and severity of endometriosis.

The epidemiology of endometriosis is poorly known as the pathophysiology and diagnosis are unclear.

As the diagnosis requires a laparoscopy, we only have data in women with pain and/or infertility. Endometriosis has been considered to be a single disease defined as 'endometrium like glands and stroma outside the uterus'. However, subtle, typical, cystic ovarian and deep endometriosis lesions should be considered to be different pathologies which occur in all combinations and with different severities. All large datasets, especially those based on hospital discharge records, consider endometriosis to be a single disease without taking into account severity. In particular, the variable prevalence and recognition of subtle lesions is problematic. Reliable surgical data are small series not permitting multivariate analysis. Endometriosis is a hereditary disease. The oxidative stress of heavy menstrual bleeding with retrograde menstruation and an altered pelvic microbiome are probably associated with increasingly severe endometriosis. Whether the prevalence is increasing, or whether endometriosis is associated with fat intake or an increased risk of cardiovascular disease is unclear.

Which Knots Are Recommended in Laparoscopic Surgery and How to Avoid Insecure Knots.

STUDY OBJECTIVE: To investigate why security of identical knot sequences is variable and how to avoid occasionally insecure knots. DESIGN: A factorial design was used to assess factors affecting the security of half knot (H) and half-hitch (S) knot combinations. The effect of tying forces and the risk factors to transform H knots into S knots were investigated. The risk factors evaluated were as follows: starting with an H1 or H2 instead of an H3 knot, inexperience, short sutures, and monomanual knot tying. Security of transformed knots, S2S1 and S2S2 knots, and their recuperation with 2 additional half hitches, SSb or SbSb, were evaluated. SETTING: Training center for laparoscopic suturing. PATIENTS: Not applicable. INTERVENTIONS: Security of knots was evaluated in vitro. MEASUREMENTS AND MAIN RESULTS: The forces that caused knot combinations to open before breaking of the suture were used to calculate the risk of opening with low forces. Tying more strongly increased the security of half knots (H2H1sH1s) (p <.02) and half hitches (p <.001). The forces needed to transform an H3 into an S3 are higher than those for an H2 (p <.001), and the risk increases when the surgeon is inexperienced (p <.001), when sutures are short (p <.001), and when monomanual knot tying (p <.001) is used. Inadvertently made S2S1 and S2S2 knots are dangerous, with the exception of the symmetric S2S2, which is stable. Unstable knots such as S2S1a and S2S2a knot combinations improve with 2 additional blocking half hitches (SbSb), but S2S2aSbSb remains occasionally insecure. CONCLUSION: To reduce the risk of accidentally transforming a first H into an S knot, it is recommended to start with an H3, tie with force, avoid short sutures, and use bimanual suturing. This permits the recommendation to use preferentially H3H2 knots or 5 half hitches (SSSbSbSb). When in doubt, half knot combinations should be secured with at least 2 blocking half hitches.

Pathogenesis of endometriosis: the genetic/epigenetic theory.

OBJECTIVE: To study the pathophysiology of endometriosis. DESIGN: Overview of observations on endometriosis. SETTING: Not applicable. PATIENT(S): None. INTERVENTIONS(S): None. MAIN OUTCOME MEASURE(S): The hypothesis is compatible with all observations. RESULT(S): Endometriosis, endometrium-like tissue outside the uterus, has a variable macroscopic appearance and a poorly understood natural history. It is a hereditary and heterogeneous disease with many biochemical changes in the lesions, which are clonal in origin. It is associated with pain, infertility, adenomyosis, and changes in the junctional zone, placentation, immunology, plasma, peritoneal fluid, and chronic inflammation of the peritoneal cavity. The Sampson hypothesis of implanted endometrial cells following retrograde menstruation, angiogenic spread, lymphogenic spread, or the metaplasia theory cannot explain all observations if metaplasia is defined as cells with reversible changes and an abnormal behavior/morphology due to the abnormal environment. We propose a polygenetic/polyepigenetic mechanism. The set of genetic and epigenetic incidents transmitted at birth could explain the hereditary aspects, the predisposition, and the endometriosis-associated changes in the endometrium, immunology, and placentation. To develop typical, cystic ovarian or deep endometriosis lesions, a variable series of additional transmissible genetic and epigenetic incidents are required to occur in a cell which may vary from endometrial to stem cells. Subtle lesions are viewed as endometrium in a different environment until additional incidents occur. Typical cystic ovarian or deep endometriosis lesions are heterogeneous and represent three different diseases. CONCLUSION(S): The genetic epigenetic theory is compatible with all observations on endometriosis. Implications for treatment and prevention are discussed.

What is the Best Surgeon's Knot? Evaluation of the Security of the Different Laparoscopic Knot Combinations.

STUDY OBJECTIVE: To investigate the security of various knot combinations in laparoscopic surgery. DESIGN: Prospective nonrandomized trial (Canadian Task Force classification II). SETTING: Storz Training Centre, Sao Paulo, Brazil. INTERVENTION: Different knot combinations (n = 2000) were performed in a laparoscopic trainer. Dry or wet 2.0 polyglycolic acid or dry 2-0 poliglecaprone 25 was used. The tails were cut at 10 mm, and the loops were tested in a dynamometer. The primary endpoints were the forces at which the knot combination opened or at which the suture broke. Resulting tail lengths were measured. MEASUREMENTS AND MAIN RESULTS: Surprisingly, the combination of a 2-throw half knot (H2) and a symmetric 1-throw half knot (H1s) (a surgical flat knot) opened at <1 Newton (N) in 2.5% of tests and at <10 N in 5% of tests. This occasional opening at low forces persisted after 1 or 2 additional H1s knots. A sequence of an H2 or a 3-throw half knot (H3) followed by a H2, either symmetric or asymmetric (H2H2 or H3H2), resulted in 100% secure knots that never opened at forces below 30 N. Other safe combinations were H2H1s followed by 2 blocking half hitches, and a sequence of 5 half hitches with 3 blocking sequences. CONCLUSION: A traditional surgical knot (H2H1s) occasionally opens with little force and thus is potentially dangerous. Safe knots are H2H2 and H3H2 combinations, a sequence of 5 half hitches with 3 blocking sequences, and H2H1s together with 2 blocking half hitches.