Instrument fatigue, fracture, and erosive corrosion of metal.

Instrument malfunction and damage are considered defects of surgical instruments. The overall incidence of critical adverse events associated with defective surgical instruments including all types of surgery is estimated to be 2 out of 19,474 (0.01%). This means an incidence of 10 in every 100,000 operations. The incidence of defective instruments in urological and endoscopic surgery is 0.31 % and 0.53 % respectively. Although the incidence is low, instrument malfunction has led to serious medical accidents during surgery. These include direct tissue damage, critical bleeding, and retained pieces of broken instruments resulting in auxiliary procedures, increased anaesthesia time and its resultant morbidity. Surgical instruments are usually durable and can be used safely for years. However, inappropriate use and wearing out by repeated usage are the major causes of defective surgical instruments. Other causes being inadequate inspection and factory defects. Surgical instruments wear out gradually through a process of fatigue, fracture, and erosive corrosion of metal. These processes are evidenced by microscopic striations in fatigue, microscopic corrosion pits or macroscopic discolouration in corrosion, and cracks in the fracture. This is in particular with the use of indigenously made instruments (factory defects) that are widely used especially in a developing country like India, as they are much cheaper than those manufactured by larger firms. In contrast to the renowned brand surgical instruments, which are usually certified by established agencies, indigenously made instruments do not have to fulfil any norms or pass any test before marketing. In our case, we used an indigenously made grasping forceps for stone retrieval. The broken prong migrated into the ureter, leading to tiresome auxiliary procedures in retrieving it, resulting in increased anaesthesia and operating room time. Though we did not encounter any morbidity, this case made us change our unit policy in using renowned brand instruments, limiting the number of instrument re-use, meticulous inspection of the instruments and better training in instrument handling to the urology trainees. There have been few reported cases on broken suture passer, the broken needle of an endostitch device, malfunctioning of robotic arms and breakage of a robotic needle driver concerned with minimally invasive surgeries.) However, there is a dearth of the literature on medical accidents resulting from endourological instruments malfunction. Anderson et al reported a case of fractured flexible ureteroscope with locked deflection requiring an open incision for retrieval.To conclude, surgical instrument malfunction and damage can occur during endourological procedure especially with indigenously made reusable devices. Using renowned instruments, proper handling, regular screening and limiting the reuse could prevent medical accidents caused by defective surgical instruments.