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. Safe practice rests on careful case selection, choosing the correct energy and distension system, and recognising and pre-empting its two signature dangers — uterine perforation and fluid-overload / dilutional hyponatraemia — with a ready emergency drill when they occur. What counts is understanding the mechanisms behind the procedure and its complications.
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.