A scalpel, or lancet, is a small and extremely sharp bladed instrument used for surgery, anatomical dissection, and also for various arts and crafts (called a hobby knife). Scalpels may be single-use disposable or re-usable, and recently Safety Scalpels are the norm in the Operating Rooms. Re-usable scalpels can have permanently attached blades that can be sharpened or, more commonly, removable single-use blades. Disposable scalpels usually have a plastic handle with an extensible blade (like a utility knife) and are used once, then the entire instrument is discarded. Scalpel blades are usually individually packed in sterile pouches but are also offered non-sterile. Double-edged scalpels are referred to as “lancets”.
Scalpel blades are usually made of hardened and tempered steel, stainless steel, or high carbon steel; in addition, titanium, ceramic, diamond and even obsidian knives are not uncommon. For example, when performing surgery under MRI guidance, steel blades are unusable (the blades would be drawn to the magnets, or may cause image artifacts). Historically, the preferred material for surgical scalpels was silver, on account of its antimicrobial properties (although the mechanics were not understood at the time). Scalpel blades are also offered by select manufacturers with a zirconium nitride-coated edge to improve sharpness and edge retention. Others manufacture blades that are polymer-coated to enhance lubricity during a cut. Alternatives to scalpels in surgical applications include electrocautery and lasers.
Reusable handle (top) and disposable scalpels (bottom):
Surgical scalpels consist of two parts, a blade and a handle. The handles are often reusable, with the blades being replaceable. In medical applications, each blade is only used once (even if just for a single, small cut).
Proper Surgical Instruments
Laser surgery is surgery that uses a laser (instead of a scalpel) to cut tissue. Examples include the use of a laser scalpel in otherwise conventional surgery, and soft-tissue laser surgery, in which the laser beam vaporizes soft tissue with high water content. Laser resurfacing is a technique in which covalent bonds of a material are dissolved by a laser, a technique invented by aesthetic plastic surgeon Thomas L Roberts, III using CO2 lasers in the 1990s. The CO2 (carbon dioxide) laser remains the gold standard for the soft tissue surgery because of the ease of simultaneous photo-thermal ablation and coagulation (and small blood capillary hemostasis).
Laser surgery is commonly used on the eye. Techniques used include LASIK, which is used to correct near and far-sightedness in vision, and photorefractive keratectomy, a procedure which permanently reshapes the cornea using an excimer laser to remove a small amount of tissue. Types of surgical lasers include carbon dioxide, argon, Nd:YAG laser, and Potassium titanyl phosphate.
- Photochemical effect: clinically referred to as photodynamic therapy. Photosensitizer (photophrin II) is administered which is taken up by the tumor tissue and later irradiated by laser light resulting in highly toxic substances with resultant necrosis of the tumor. Photodynamic therapy is used in palliation of oesophagial and bronchial carcinoma and ablation of mucosal cancers of Gastrointestinal tract and urinary bladder.
- Photoablative effect: Used in eye surgeries like band keratoplast, and endartectomy of peripheral blood vessels.
- Photothermal effect: this property is used for endoscopic control of bleeding e.g. Bleeding peptic ulcers, oesophagial varices
- Photomechanical effect: used in intraluminal lithotripsy
A range of lasers such as erbium, dye, and CO2 are used to treat various skin conditions including scars, vascular and pigmented lesions, and for photorejuvenation.
Various types of laser surgery are used to treat refractive error:
Lasers are also used to treat non-refractive conditions, such as:
Laser endarterectomy is a technique in which an entire atheromatous plaque in the artery is excised. Laser recanalization of blocked arteries. other applications include laser assisted angioplasties and laser assisted vascular anastomosis.
Lasers are used to treat several disorders in foot and ankle surgery. They are used to remove benign and malignant tumors, treat bunions, debride ulcers and burns, excise epidermal nevi, blue rubber bleb nevi, and keloids, and the removal of hypertrophic scars and tattoos.
A carbon dioxide laser (CO2) is used in surgery to treat onychocryptosis (ingrown nails), onychauxis (club nails), onychogryposis (rams horn nail), and onychomycosis (fungus nail).
- Peritoneum-Laser is used for adhesiolysis.
- Peptic ulcer disease and oesophageal varices - Laser photoablation is done.
- Coagulation of vascular malformations of stomach, duodenum and colon.
- Lasers can be effectively used to treat early gastric cancers provided they are less than 4 cm and without lymph node involvement. Lasers are also used in treating oral submucous fibrosis.
- Palliative laser therapy is given in advanced oesophageal cancers with obstruction of lumen. Recanalisation of the lumen is done which allows the patient to resume soft diet and maintain hydration.
- Ablative laser therapy is used in advanced colorectal cancers to relieve obstruction and to control bleeding.
- Laser surgery used in hemorrhoidectomy, and is a relatively popular and non-invasive method of hemorrhoid removal.
- Laser-assisted liver resections have been done using carbon dioxide and Nd:YAG lasers.
- Ablation of liver tumors can be achieved by selective photovaporization of the tumor.
- Endoscopic laser lithotripsy is a safer modality compared to electrohydraulic lithotripsy.
The CO2 laser is used in oral and dental surgery for virtually all soft-tissue procedures, such as gingivecomies, vestibuloplasties, frenectomies and operculectomies. The CO2 10,600 nm wavelength is safe around implants as it is reflected by titanium, and thus has been gaining popularity in the field of periodontology. The laser may also be effective in treating peri-implantitis.
Laser spine surgery first began seeing clinical use in the 1980s and was primarily used within discectomy to treat lumbar disc disease under the notion that heating a bulging disc vaporized enough tissue to relieve pressure on the nerves and help alleviate pain.
Since that time, laser spine surgery has become one of the most marketed forms of minimally invasive spine surgery, despite the fact that it has never been studied in a controlled clinical trial to determine its effectiveness apart from disc decompression. Evidence-based data surrounding the use of lasers in spine surgery is limited primarily due to the presence of a number of challenging factors including patient selection, operative indications in the type of laser used in the procedure. As a result, the official Blue Cross of Idaho position on laser disc surgery concluded:
"Evidence on decompression of the intervertebral disc using laser energy consists of observational studies. Given the variable natural history of back pain and the possibility of placebo effects with this treatment, observational studies are insufficient to permit conclusions concerning the effect of this technology on health outcomes."
The CO2 laser is also used in gynecology, genitourinary, general and thoracic surgery, otorhinolaryngology, orthopedic, and neurosurgery.