Infection Prevention and Gynecologic Surgery

Shout out to Taylor DeGiulio for today’s episode idea! We’re doing a pretty close reading of ACOG PB 195 if you want to follow along!

SSI represents the most common complication after GYN surgery, however definitions of this may surprise you. The National Surgical Quality Improvement Program (NSQIP) divides SSI up into three broad categories, with their definitions below:

  1. Superficial incisional: occurs within 30 days of surgery, involving only skin or subcutaneous tissue.

  2. Deep incisional: occurs within 30 days of surgery without an implant, or within 1 year of surgery with an implant, and involves deep soft tissues (rectus muscle, fascia).

  3. Organ space: occurs within 30 days of surgery without an implant, or within 1 year of surgery with an implant, and involves any other area manipulated during operative procedure (i.e., osteomyelitis if bone, endometritis or vaginal cuff for GYN, etc.)

  • In addition to satisfying these time and location definitions, an SSI also must have one of the following characteristics present:

    • Purulent drainage from the area of infection.

    • Spontaneous dehiscence or deliberate opening of a wound by the surgeon, with organisms subsequently obtained from an aseptically collected culture; or not cultured, but the patient displays signs/symptoms) of infection (i.e., fever, localized pain or tenderness, redness, etc.).

    • Abscess or other evidence of infection noted on examination.

    • Diagnosis of infection made by surgeon or attending physician.

In GYN surgery, our threats for infection lie primarily from vaginal organisms or skin organisms; however we may also come into contact with fecal content or enteric contents as well. Thinking about the organisms we’re helping to bolster defense against will help in selecting a preventive antibiotic. Thinking about the wound class is a simple way to characterize this:

ACOG PB 195

ACOG also recommends a number of perioperative considerations/techniques to reduce SSI:

  1. Treat remote infections - this one seems pretty obvious. If there’s an infection going on, like a skin infection or a UTI, it’s likely best to postpone surgery in favor of treating the infection!

  2. Do not shave the incision site - Preoperative shaving by patients themselves has actually been shown to be likely harmful, increasing the risk of infection by introducing a nidus for infection remote from surgery. If hair needs to be clipped, it should be done immediately pre-op with electric clippers.

  3. Prevent preop hyperglycemia - blood glucose should be targeted to < 200 mg/dL for both non-diabetic and diabetic patients before proceeding with surgery. Performing a preoperative random blood sugar prior to major surgery is a practice our hospital has implemented to identify diabetes in our patients, and to prevent SSI.

  4. Advise patients to shower or bathe with full body soap on at least the night before surgery -We found it fairly surprising that no particular soap is recommended over another. Many offices offer patients a chlorhexidine soap for use the night before surgery. The soap significantly reduces risk of cellulitis versus no bathing.

  5. Use alcohol-based preop skin prep, unless contraindicated - chlorhexidine-alcohol combinations have been proven in RCTs and meta-analyses to be superior to povidine-iodine for preoperative skin preparation. For mucosal sites such as the vagina, where high alcohol concentrations should not be used due to irritation risk, povidine-iodine or chlorexidine soap solutions should be used.

  6. Maintain appropriate aseptic technique - Of course, right? But in addition, our surgical technique does matter! Effective hemostasis while preserving vital blood supply, maintaining normothermia and reducing operative time, gentle tissue handling, avoiding inadvertent injuries, using drains when appropriate, and eradicating dead space can all help to reduce risk of SSI.

  7. Minimize OR traffic - safety bundles that have included components to reduce opening of OR doors during cases have been shown to reduce SSI.

  8. For hysterectomy, consider preop screening for bacterial vaginosis - prior to routine use of antibiotic prophylaxis for hysterectomy, use of metronidazole pre-op in patients who screened positive for BV reduced SSI. These studies haven’t been repeated with systematic antibiotic prophylaxis, but given the data, ACOG does state that screening is reasonable at the preop visit.

Alright, now time for the antibiotics! We dive deeper in the podcast, but PB 195 will give you the quick version here in the tables:

ACOG PB 195

ACOG PB 195

Gestational Trophoblastic Disease

On today’s podcast, we welcome Jenna Emerson, MD, the current 3rd year fellow in gynecologic oncology and alumnus of the residency at Brown University / Women and Infants! Jenna takes us today through the often confusing world of GTD (or GTN, or GTT).

GTD encompasses several distinct disease entities, including complete and partial molar pregnancy, invasive moles, gestational choriocarcinoma, and placental-site trophoblastic tumors (PSTT).

Molar Pregnancies are a form of non-invasive GTD, and will be encountered by the general OB/GYN. It’s estimated 1:600 TABs will pathologically be molar pregnancies. 20% will lead to malignant GTD and require treatment, with complete moles more often leading to malignancy than partial moles.

The distinction of complete versus partial moles make for great test questions, though the management is the same. There are two main distinctions:

  • Karyotype – partial is triploid, complete is diploid

  • Clinical features – complete is completely weird, while partial only partially weird. Though the ACOG PB 53 has since been retired, this table is helpful in going over the main differences:

ACOG PB 53

Moles generally present with first trimester bleeding or characteristic US findings (“snowstorm appearance”). Initial management requires a number of steps for evacuation or hysterectomy. Be sure to check out the NCCN guidelines (membership required, but free!) for review.

Malignant GTD occurs post-molar if bHCG plateaus, increases, or is persistently positive. This ultimately requires staging per FIGO criteria:

NCCN / FIGO

NCCN / FIGO

If disease is low risk and local disease only, management is hysterectomy vs repeat D&C. A second curettage for low risk cures 40% of patient, and avoids need for chemotherapy. This is a change from traditional teaching, based on a prospective trial published in 2016.

If this surgical management is unsuccessful while following bHCG, then it’s time to move to chemotherapy. Low risk disease is treated with single agent chemo (MTX or Actin-D). Per GOG174, Actin-D has a higher complete response rate, but is more toxic than MTX. High risk disease is treated with EMACO. Check out the NCCN guidelines for more information on these regimens. 

Choriocarcinoma and Placental Site Trophoblastic Tumor

  • Choriocarcinoma can follow term pregnancies (50%), moles (25%), or non-term histologically normal pregnancies (25%). They have early systemic mets, and require chemotherapy. The staging system is the same as above to decide single vs. multi-agent therapy. These are very vascular, so the classic CREOG answer is that you should not biopsy a suspected choriocarcinoma!

  • PSTT, epithelioid trophoblastic tumor – both of these are very rare and can follow any pregnancy. These should be referred to specialized centers, and are most commonly treated with hysterectomy.

Diagnostic Dilemmas

We reviewed a number of scenarios that can pose diagnostic challenges. In brief:

  • Malignant GTD following non-molar pregnancies

    • In the case of persistent AUB for > 6weeks after pregnancy, a bHCG should be checked to rule out new pregnancy or GTD

  • Choriocarcinoma as malignancy of unknown primary 

    • Mets have been reported in pretty much every body site.

    • Serum beta (which will almost certainly be above discriminatory zone) and pelvic US to r/o pregnancy allow for diagnosis.

  • Phantom hCG – heterophile antibodies

    • Positive serum hCG testing can result due to relatively non-specific circulating antibodies which bind to secondary antibody in a sandwich assay (antigen 🡪 primary antibody detects antigen-labeled secondary antibody, which detects primary antibody and has detectable indicator).

    • Several ways to identify: pos serum with neg urine (antibodies aren’t shed in the urine but bHCG glycoprotein is), value doesn’t decrease with serial dilutions, or can send to a separate lab which may use separate secondary assay.

  • Postmenopausal hCG

    • Baseline small amount of hCG produced by the pituitary – rises in peri- and post-menopausal, during chemo. Typically beta is 5 or less but can occasionally be higher. Confirm by checking LH – if LH is consistent with menopause, this confirms pituitary source.

Adnexal Masses Part 1: Imaging

Today we’re embarking on a multi-part series through adnexal masses.

To frame our initial conversation on imaging features of adnexal masses, we’ve relied heavily on a golden piece of literature from the Radiological Society of North America, detailing the features and management of these findings on imaging. This paper contains a super nice table that should be considered a table-side reference for your own viewing of images.

Generally speaking, signs more suggestive of malignancy include:

  • Patient age/menopausal status: One of the biggest contributing risk factors, even before you know what the cyst looks like. In postmenopausal women with asymptomatic adnexal masses, the incidence of malignancy approaches 30%, while it is only 6-11% in premenopausal women.

  • Large size: cysts greater than 5cm should receive consideration for surgical intervention or closer follow up in premenopausal women. In postmenopausal women though, even small 1cm cysts should be considered for close interval follow up at a minimum.

  • Thickness: thicker walls (>3mm) portend more significant pathology.

  • Septations: multiple septations are also concerning for malignancy, though again this corresponds with the thickness; thinner septations may suggest more likely benign disease.

  • Nodularity: cysts with nodules or calcifications, particularly with vascularity, are more concerning.

  • Contents: one of the more nuanced findings; however, can help determine etiology: i.e., cysts with a reticular or lacy appearance are more suggestive of hemorrhagic cysts, while hyper echoic lines and dots with areas of acoustic shadowing are more suggestive of dermoid cysts.

Be sure to also check out ACOG PB 174 (membership required) and/or the OBG Project’s helpful bulleted summary! We definitely think looking through images alongside descriptive text is the primary way to learn this information, and we hope the podcast can help supplement that for some of you.

Abnormal Uterine Bleeding: The Basics

Today we talk through the varied etiologies and a basic workup for a common GYN complaint: abnormal uterine bleeding. ACOG PB 128 makes for good companion reading for women of reproductive age.

The terminology of AUB has changed quite a bit, and you may still hear older terms being used. “Dysfunctional uterine bleeding” or DUB has fallen out of favor, as have terms such as metrorrhagia or menorrhagia, yielding instead to simpler terminology such as prolonged menstrual bleeding and heavy menstrual bleeding, respectively. The terms such as oligomenorrhea (bleeding cycles > 35 days apart) and polymenorrhea (cycles < 21 days apart) are also in use to some degree.

Heavy bleeding is difficult to discern, but for research purposes has been described as >80cc blood loss per cycle. In clinical practice, this is obviously impractical, so we rely on subjective descriptions of heavy bleeding to guide care.

The biggest takeaways from this episode include the PALM-COIEN classification of bleeding by FIGO, as well as the common culprits of bleeding by age group. Remember also the criteria for working up for disorders of coagulation, which we’ve put here (though contained in the practice bulletin).

Stay tuned for future episodes about the treatments of these various etiologies, or check out our friends at The OBG Project for excellent summaries of guidelines and new literature!

ACOG PB 128

ACOG PB 128

ACOG PB 128

Cervical Cancer Screening and Prevention

Today we discuss one of the basic screening tools of the OB-GYN office: the Pap smear. Named for Georgios (George) Papanikolau, credited for its creation around 1923, it is a test that has singlehandedly changed the face of cancer screening. With its widespread use, the incidence of cervical cancer in the US has dropped from 14.8 / 100k women in 1975, to 6.7 / 100k women in 2011. The converse also demonstrates the importance of this routine test: 50% of those diagnosed with cervical cancer have never had Pap screening, and 10% have not had screening within the preceding 5 years.

We also now know and can test for the presence of oncogenic strains of human papilloma virus, or HPV. Types 16 and 18 account for over 70% of cervical cancer worldwide, and 12 other strains account for the remaining majority of cases. Ongoing trials are looking at whether HPV screening may ultimately supplant cytology as the preferred 1st test, but HPV screening has added another excellent tool to help OB-GYNs discuss risk and prevent cancer in their patients.

Follow along with ACOG PB 168!

So what are the screening guidelines?
In the immunocompetent patient, they are as follows:

  • < 21 years: Screening should not be performed, even in the presence of behavior-related risk factors.

    • Only 0.1% of cervical cancer cases occur before age 20.

    • Women younger than 21 with no immunocompromising conditions generally clear HPV infection between 8-24 months after exposure. 

    • This population should have discussion about safe sex practices to avoid exposure to STIs including HPV, and strong consideration for HPV vaccination.

  • 21 - 29 years: Screening should be performed using cytology alone every 3 years.

    • Annual screening is discouraged in this group, as it exposes patients to a much more significant number of unnecessary procedures for minimal improvement in outcomes. 

    • HPV co-testing is not recommended in this group; however, HPV reflex testing in the event of an ASC-US Pap smear may be considered to determine need for colposcopy.

  • 30 - 65 years: Screening should be performed with cytology alone every 3 years, or cytology with HPV co-testing every 5 years. 

    • In this population, with a negative cytology and negative HPV test, the risk of developing CIN 2 or 3 in the next 4-6 years is extremely low, based on large database studies (approximately 0.08% risk over 5 years). The risk is higher, but also quite low, with cytology alone (0.26% over 5 years). This is the rationale for the screening interval being extended.

    • RCTs have demonstrated in this population that cotesting has a number of distinct advantages:

      • Cotesting has a higher detection rate of high-grade dysplasia in first round of screening, and decreases risk of CIN3 or cancer in subsequent screening.

      • Cotesting likely has a better pickup rate for cervical adenocarcinomas (vs. squamous cell) than cytology alone.

  • > 65 years, or post-benign hysterectomy: Screening should be discontinued, provided that:

    • There has been no history of CIN2, CIN3, or AIS in the preceding 20 years, and:

    • There are adequate negative prior results:

      • 3 consecutive negative cytology results within last 10 years, or

      • 2 consecutive negative cotest results within the last 10 years, with the most recent test performed within the past 5 years.

    • Women in this age group do get cervical cancer; however, the majority of these cases occur in women who are not screened, or in those who are underscreened.

    • The changes of menopause may also cause false positive Pap tests in this group, leading to likely unnecessary additional and invasive testing and procedures.

Behavioral risks, such as cigarette smoking, new or multiple sexual partners, or early sexual debut, may increase risk of HPV acquisition or persistence, but do not alter screening recommendations.

However, two particular conditions do merit changes to screening:

  • In utero diethylstilbestrol (DES) exposure:

  • DES was an estrogen that was manufactured and prescribed in the US during the 1930s until 1971. It was thought that the medication helped with premature birth or history of miscarriage, though by the 1950s it had been demonstrated to be ineffective.

  • ACOG states that annual cytology is reasonable in women exposed to DES in utero, as cohort studies have demonstrated a much higher incidence of clear cell adenocarcinoma of the vagina in women born to mothers who took DES or similar medications. DES has also been associated with other health problems in both men and women.

  • You can find a list of DES and related medications online at the CDC, and there is an interactive tool for patients to use to determine if they may be at risk.

  • HIV or immunocompromising conditions:

    • Women infected with HIV or with other immunocompromising conditions are less readily able to clear HPV infections. Thus, the recommendations in this population differ:

  • Screening should begin within 1 year of sexual activity, and no later than age 21.

  • In women less than 30, If the first screen is negative, it should be repeated in 12 months. If three consecutive annual screens are normal, screening may be spaced to regular intervals (i.e., q3 year cytology). HPV cotesting is not recommended.

  • In women older than 30, three annual tests should be normal, before moving to cytology alone or co-testing. Screening intervals should be every 3 years in this population, regardless of the method chosen. 

  • Screening should continue for the lifetime of the woman, and not stop at age 65.

What about HPV vaccination?

HPV vaccination has been an incredible advance for primary prevention of cancer. Currently available include a bivalent vaccine, a quadrivalent vaccine, and a 9-valent vaccine. All of these cover HPV types 16 and 18. The 9-valent vaccine covers up to 50% additional cases of cervical cancer versus the bivalent vaccine. The 9-valent vaccine should be given to boys and girls ages 9-26. 

  • For those receiving their first dose before age 15, only two doses given 6 months apart are needed. 

  • For those receiving it after age 15, 3 doses given at 0, 1-2, and 6 months apart are recommended. 

HPV vaccination is not recommended during pregnancy, but also hCG screening is not necessary prior to initiating the dose. If pregnancy interrupts the schedule, it should be resumed postpartum without need for redosing. Studies are ongoing to determine the safety of HPV vaccination during pregnancy. 

In June 2019, the CDC’s advisory council on immunization practices (ACIP) updated its HPV vaccination recommendations, to extend recommendation for vaccination for all persons up through age 45, after the FDA approved this in October 2018. While this hasn’t made it into official ACOG practice guidance yet, it’s safe to say that this is forthcoming!

Further Reading from the OBG Project:

USPSTF Releases Final Cervical Cancer Screening Guidelines – Including ‘HPV Only’ Option
Screening for Cervical Cancer in the Woman at Average Risk
What is the Most Efficient Method for Cervical Cancer Screening?
Cervical Cytology and HPV Screening in the HIV Positive Woman

Cervical Cancer Screening Strategies and Cost-Effectiveness: Which is the Best?