Clinical overview
Operative hysteroscopy is the endoscopic treatment of intrauterine pathology under direct vision, performed by passing instruments through the cervix into a uterine cavity distended with fluid. It is the definitive modern tool for managing the structural causes of abnormal uterine bleeding, intrauterine adhesions, septa, retained products, lost intrauterine devices, and submucous fibroids — pathology that previously required blind dilatation and curettage or laparotomy. As a registrar you will be expected not merely to list its indications but to reason through case selection, choose the correct energy and distension system, recognise and pre-empt its two signature dangers — uterine perforation and fluid-overload / dilutional hyponatraemia — and run the emergency drill when they occur. That is the heart of this HOTS objective: the verb is illustrate the principles, so the weight falls on understanding the mechanisms behind the procedure and its complications, not rote recall.
In the South African setting the technique sits unevenly across levels of care. Diagnostic and simple outpatient hysteroscopy is increasingly available, but resectoscopic surgery and especially the safest distension-monitoring equipment cluster in regional and tertiary units. A registrar must therefore know both the gold-standard technique and how to operate (and when to refer) where automated fluid-deficit monitors and bipolar generators are not on the trolley. Hysteroscopy is also the natural complement to laparoscopy and shares its electrosurgical hazards — read this alongside electrosurgery-safety and mis-complication-prevention.
Core knowledge
Figure F9.1 — Operative hysteroscopy, plan–pair–proceed: select the right patient (indications/contraindications), map the lesion (FIGO submucous fibroid type), pair the energy to the distension medium, and follow a safe running sequence.
Distension media — the central physiological concept
The uterine cavity is a potential space; to see and operate you must distend it, and the choice of medium dictates the entire safety profile. The key principle is that distension media are infused under pressure into a vascular organ with open venous channels, so any medium can be absorbed (intravasation) into the circulation, and the volume and composition of what is absorbed is what kills patients.
- Monopolar electrosurgery requires a non-conductive, electrolyte-free medium (classically 1.5% glycine, or sorbitol/mannitol). These are hypo-osmolar or electrolyte-free, so excess absorption causes dilutional hyponatraemia, hypo-osmolality, cerebral oedema and, with glycine, hyperammonaemia — the "TURP-type" syndrome. This is the most dangerous combination.
- Bipolar electrosurgery (e.g. resectoscopes using saline-compatible electrodes) uses normal saline (0.9%), an isotonic, electrolyte-containing fluid. Absorption still causes circulatory overload and pulmonary oedema, but does not cause the profound hyponatraemia of electrolyte-free media — which is why bipolar-in-saline is the safer modern default. Saline cannot be used with monopolar current because it dissipates the current.
- Carbon dioxide is used for diagnostic hysteroscopy only — never for operative work, because of the gas-embolism risk and inability to clear blood.
- Low-viscosity vs high-viscosity: most operative work uses low-viscosity fluids run through an inflow/outflow system; the now-rare high-viscosity Hyskon (dextran) carried anaphylaxis and coagulopathy risks.
Standard teaching is to keep intrauterine distension pressure at or below mean arterial pressure (commonly quoted as roughly the 70–100 mmHg range) to limit intravasation while maintaining a view; this is conventional practice rather than a single trial-defined threshold, so treat the exact number cautiously.
Energy and instruments
The classic resectoscope is a continuous-flow sheath carrying a working element with a wire loop, rollerball or vaporising electrode, used to resect (fibroids, polyps), ablate the endometrium, or cut a septum. Modern alternatives include mechanical tissue-removal/morcellation systems (rotating blade with integrated suction — no thermal energy, hence no electrosurgical risk to adjacent structures and a cleaner view because chips are aspirated continuously) and miniature mechanical instruments (scissors, graspers) for "see-and-treat" outpatient work. Bipolar electrodes (e.g. needle/loop in saline) have largely displaced monopolar resectoscopy where equipment allows.
Fibroid classification
Submucous fibroid resectability is predicted by the FIGO/ESGE submucous classification:
- Type 0 — entirely intracavitary, pedunculated; ideal for hysteroscopic resection.
- Type 1 — <50% intramural extension.
- Type 2 — ≥50% intramural extension; higher fluid absorption, more likely to need a staged two-step procedure, higher perforation risk.
The deeper the intramural component, the longer the operating time, the greater the fluid deficit and the higher the risk — a direct illustration of how anatomy drives complication risk.
Assessment
Indications
Operative hysteroscopy is indicated for:
- Endometrial polyps causing bleeding, infertility or detected on screening.
- Submucous fibroids (FIGO 0–2) causing heavy menstrual bleeding or subfertility — see heavy-menstrual-bleeding-management and fibroids.
- Uterine septum in the context of recurrent miscarriage or subfertility (metroplasty).
- Intrauterine adhesions (Asherman syndrome) — adhesiolysis, often with post-operative measures to prevent reformation.
- Retained products of conception or placental remnants resistant to medical management, and retained/embedded IUDs or lost threads.
- Endometrial ablation/resection for heavy menstrual bleeding in women who have completed childbearing and in whom malignancy is excluded.
- Targeted/directed biopsy of focal lesions, and proximal tubal cannulation.
Patient evaluation
History and examination should establish the bleeding pattern, fertility intentions (which dictate whether ablation is even permissible), and contraindications. Hysteroscopy is contraindicated in active pelvic infection, known or untreated cervical/endometrial cancer, and viable intrauterine pregnancy; relative caution applies to active heavy bleeding (impairs the view) and cervical stenosis.
Pre-operative imaging is essential: transvaginal ultrasound maps fibroid number, size and FIGO type, and saline-infusion sonography or office hysteroscopy confirms an intracavitary lesion. Endometrial sampling to exclude malignancy is mandatory before any ablative procedure and before resecting in a woman with risk factors for endometrial pathology — never destroy an endometrium you have not characterised. Apply the same ultrasound discipline described in ultrasound-malignancy-signs and ultrasound-knobology-doppler-safety.
In the SA context, screen and optimise for anaemia (common with chronic menorrhagia), and address HIV status: ensure women are on ART and clinically stable, manage any genital infection first, and apply universal precautions — see hiv-gynaecology. Cervical screening status should be current per the national programme — see cervical-screening-sa.
Anaesthesia and setting
Diagnostic and minor "see-and-treat" procedures can be done in the outpatient/office setting without anaesthesia or with paracervical block and analgesia; vasovagal reaction is the commonest minor adverse event. Larger resections (Type 1–2 fibroids, extensive adhesiolysis, ablation) are usually done under regional or general anaesthesia in theatre. Where ablation is offered, second-generation global ablation devices are simpler and quicker than resectoscopic (first-generation) ablation, though equipment availability constrains choice in many SA units.
Management
Running the procedure safely
A safe operative hysteroscopy is a disciplined sequence:
- WHO Surgical Safety Checklist and team brief, confirming the planned procedure, distension medium, generator settings and a stated fluid-deficit ceiling before starting.
- Cervical preparation and dilatation under direct or ultrasound guidance; gentle technique because forced dilatation of a stenosed cervix is a major cause of creating a false passage and perforation.
- Establish distension with the correct medium for the energy modality (saline for bipolar/mechanical; electrolyte-free only if monopolar), at the lowest pressure giving an adequate view.
- Systematic survey of the cavity, tubal ostia and lesion before any cutting.
- Targeted resection with the electrode moved towards the operator and current applied only on the withdrawal stroke with the electrode in view — never activate energy blind or while advancing.
- Continuous fluid-balance monitoring (see below) and continuous communication between surgeon, scrub and anaesthetist.
- Plan to stage large Type 2 fibroids rather than chase the intramural portion into rising deficit and lengthening time.
Fluid management — the discipline that prevents disaster
The single most important intra-operative principle is real-time measurement of the fluid deficit (volume infused minus volume recovered), announced regularly, with pre-agreed stop thresholds. AAGL guidance on hysteroscopic distension media frames the safe ceilings, and the widely taught thresholds are:
- Electrolyte-free (hypotonic) media (e.g. glycine, sorbitol/mannitol): stop the procedure at a deficit of around 1000 mL (lower, ~750 mL, in older, frail or cardiopulmonary-compromised women).
- Isotonic saline (bipolar/mechanical): a higher ceiling of around 2500 mL in fit patients, because the danger is volume overload rather than hyponatraemia — but still stop and reassess.
Treat these as the conventional teaching thresholds (AAGL-aligned) and read the exact figures cautiously — the principle (measure continuously, set a ceiling beforehand, stop early in the vulnerable) matters more than memorising a number. An automated inflow/outflow fluid-monitoring system that displays deficit live is the safest setup; where it is unavailable, deficit must be measured manually and frequently. This is precisely the kind of resource gap a SA registrar must plan around: if you cannot monitor deficit reliably, limit the scope of what you attempt and have a low threshold to stage or refer to a regional/tertiary unit.
Specific procedures — practical points
- Polypectomy: resect to the base; mechanical morcellation gives a clean specimen and view.
- Myomectomy: Type 0 fully resectable in one sitting; Type 2 often staged. GnRH analogue pre-treatment can shrink large fibroids and thin the endometrium but may make the plane harder.
- Septoplasty/metroplasty: divide the avascular septum in the midline until both ostia are seen in one view; little bleeding signals you are in the right (avascular) plane.
- Adhesiolysis (Asherman): cold scissors preferred to limit thermal endometrial damage; post-operative oestrogen and a physical barrier (balloon/IUD) are commonly used to reduce re-adhesion, though evidence is limited — flag this as an area of uncertain evidence.
- Endometrial ablation: only after malignancy excluded and childbearing complete; contraception must continue (pregnancy after ablation is high-risk). Resectoscopic (first-generation) ablation demands a thinned endometrium — performed early in the follicular phase or after endometrial preparation — to reach the basalis uniformly; second-generation global devices are less operator-dependent but are not universally available in SA public-sector theatres.
- Lost/embedded IUD or retained products: direct visualisation lets you grasp and remove the device or remnant under vision rather than blindly, sparing the cavity unnecessary trauma; confirm complete removal before withdrawing.
Red flags / pitfalls
EMERGENCY DRILL — fluid overload / dilutional hyponatraemia (TURP-type syndrome)
This is the killer. Suspect it the moment the fluid deficit crosses the threshold, or with bradycardia, hypertension then hypotension, restlessness, nausea/vomiting, visual disturbance, confusion or seizures (often unmasked only as the patient wakes).
- STOP operating and stop the infusion immediately. Remove the hysteroscope.
- Call for help — alert the anaesthetist and senior obstetrician; declare an emergency.
- Send urgent blood for serum sodium and osmolality; assess airway, breathing, circulation.
- For symptomatic / severe acute hyponatraemia with neurological signs, the treatment is controlled correction with hypertonic (e.g. 3%) saline guided by the anaesthetist/critical-care team, with frequent sodium monitoring to avoid over-rapid correction; fluid restriction and a loop diuretic address volume overload and pulmonary oedema.
- Do not over-correct sodium — rapid correction of chronic/profound hyponatraemia risks osmotic demyelination; correction rate must be deliberate and monitored.
- Escalate to high-care/ICU for monitoring — this is a shock-management- and critical-care-level event. In SA, ensure early communication with the regional/tertiary referral unit if you are at a district hospital.
Prevention beats rescue: use isotonic saline with bipolar/mechanical instruments whenever possible, monitor deficit continuously, set and honour the stop threshold, keep distension pressure low, and stage long cases.
EMERGENCY DRILL — uterine perforation
Suspected when there is sudden loss of distension, a falling view, the instrument advancing further than the known cavity depth, or visualisation of bowel/omentum.
- Stop, and do not withdraw an activated or energised instrument through the defect.
- Withdraw the hysteroscope gently and assess.
- A perforation made with a blunt dilator/scope, with no energy and no bleeding, is usually managed conservatively with observation, uterotonics if needed, and antibiotics at clinical discretion.
- A perforation made with an activated electrode, a sharp instrument, or with signs of bleeding, broad-ligament haematoma, or possible bowel/bladder/vessel injury, mandates immediate laparoscopy or laparotomy to inspect adjacent viscera and achieve haemostasis — thermal bowel injury can present late, so a high index of suspicion is required (the same principle as in mis-complication-prevention).
- Lateral perforations risk uterine vessel injury and concealed haemorrhage — monitor for shock.
Other pitfalls
- Gas embolism — rare but can be fatal; minimise air in tubing, avoid Trendelenburg-driven air entrainment; sudden cardiorespiratory collapse with a "mill-wheel" murmur is the red flag.
- Creating a false passage / failed entry in a stenosed cervix — ultrasound guidance and gentle dilatation reduce this.
- Infection — screen and treat first; haematometra and endometritis can follow ablation.
- Operating without histology — never ablate or destroy endometrium without excluding malignancy.
- Late: pregnancy after ablation, post-ablation tubal sterilisation syndrome, and intrauterine adhesion (especially after extensive resection).
- Forgetting the SA resource reality — attempting a Type 2 resection without live deficit monitoring is the classic avoidable error; downscale or refer. Equally, do not let availability of a monopolar resectoscope tempt you into an electrolyte-free medium for a long case at a district hospital without the sodium-monitoring and high-care backup to rescue a TURP-type syndrome — match the procedure's risk to the level of care.
- Premature reassurance after perforation — a patient who looks well immediately after a thermal perforation can still have an evolving bowel injury; arrange observation and clear safety-netting rather than discharging blindly.
Evidence anchors
- AAGL practice guidelines on hysteroscopic distension media and fluid-deficit limits — the source for safe-deficit ceilings (electrolyte-free vs isotonic) and electrosurgery-medium pairing (as listed in the verified technical/perioperative O&G sources).
- RCOG Green-top Guideline No. 59 — Best Practice in Outpatient Hysteroscopy — patient selection, "see-and-treat" and outpatient safety.
- RCOG Green-top Guideline No. 49 — Preventing Entry-related Gynaecological Laparoscopic Injuries — shared principles for recognising and managing visceral/vascular injury after perforation.
- WHO Surgical Safety Checklist — mandatory team brief, distension-medium and deficit-ceiling confirmation.
- FIGO/ESGE submucous fibroid classification (Types 0–2) — case selection and predicted resectability/risk.
- NICE NG88 — Heavy Menstrual Bleeding: Assessment and Management — context for hysteroscopic treatment vs alternatives in menorrhagia.
- SA National Integrated Maternal and Perinatal Care Guideline (NDoH, 2024) and SA EML (Hospital Level, current edition) — for the SA service framework, peri-operative medication availability, and referral-pathway/level-of-care realities (regional/tertiary clustering of resectoscopic equipment).
- SA HIV management (NDoH Consolidated ART Guidelines 2023; SAHCS 2023) — peri-operative HIV optimisation and universal precautions.