Abstract
Several techniques for castration of cryptorchid cats have been described. In this case report, the use of laparoscopy for castration of a bilateral cryptorchid cat (with testes located in the abdomen) is described. Three trocars were inserted into the abdominal cavity, the testicles were easily identified adjacent to the urinary bladder. Haemostasis of the gubernaculum testis and spermatic cord was achieved with bipolar cauterisation. The testicles were easily removed in approximately 20 min. To the authors' knowledge this is the first report of the use of laparoscopy for the treatment of cryptorchidism in cats.
Cryptorchidism is a disorder rarely reported in cats (Richardson & Mullen 1993). The incidence of this condition in dogs is about 1.2% (Hayes et al 1985), while the prevalence of cryptorchidism in cats has not been documented. In a study performed at the Animal Medical Centre (New York, USA) the incidence of cryptorchidism in cats was 3.8% (Richardson & Mullen 1993), while another study reported an incidence of 1.7% (Millis et al 1992). Cats of certain breeds may be predisposed to cryptorchidism: according to the study performed at the Animal Medical Centre (Richardson & Mullen 1993), Persian cats were over-represented (20 percent of 50 patients); this trend was also evident in another study (Millis et al 1992). Cryptorchidism is presumed to be heritable in cats and a polygenic mode of inheritance has been suggested (Herron & Stern 1980); for this reason castration of the affected tomcat and his removal from the breeding line should be recommended. Several techniques of orchiectomy in cryptorchid cats have been described. Approximately half of the retained testicles have an abdominal location, for this reason a caudal ventral midline approach is generally recommended (Richardson & Mullen 1993, Millis et al 1992). When performing reproductive surgery, laparoscopy is an alternative to laparotomy as it provides adequate views of reproductive anatomy with a minimally invasive approach. This technique has been used extensively in reproductive studies in pigs, goats, sheep, horses, cattle, dogs, cats, and primates (Freeman & Hendrickson 1999). Laparoscopy has been used to perform many surgical procedures in small animal reproduction including crypt-orchidectomy in dogs (Gallagher et al 1992, Freeman & Hendrickson 1999, Moriconi et al 1989, Minami et al 1997, Pena et al 1998, Vannozzi et al 2000). The present paper reports successful orchiectomy by laparoscopy in a bilateral cryptorchid cat.
Case report
A 14-month-old male domestic shorthaired cat was presented to the Department of Veterinary Clinical Sciences, University of Pisa for evaluation of undescended testicles. The cat had been with its owner from eight weeks of age. Absence of testicles from the scrotal sac had been diagnosed by the referring veterinarian at three months of age. On clinical examination pulse rate was 140 beats/min, respiration rate was 25 breaths/min, temperature was 38.5°C and the cat was in good physical condition. Clinical examination confirmed the absence of both testicles from the scrotum. Both inguinal canals and prescrotal subcutaneous fat were accurately palpated, but testicles were not identified. An abdominal location was presumed. The owner agreed to have an exploratory laparoscopy performed on the cat in order to localise and remove the abdominal testicles. Preoperative blood cell count and serum biochemistry profile were within their normal ranges: RBC 8.150 ×106 μl, Hct 39%, HGB 12.8 g/dl, WBC 12.300 μl, albumin 2.3 g/dl, total protein 6 g/dl, ALT 28 U/l, GGT 1.9 U/l, BUN 25 mg/dl, creatinine 0.9 mg/dl. Tests for feline leukaemia virus and feline immunodeficiency virus were negative. Anaesthesia was induced with ketamine (Ketavet 50; Gellini, Italy) at the dose of 0.25 mg/kg body weight administered intramuscularly and medetomidine (Domitor; Centralvet-Vetem, Italy) at the dose of 50 μg/kg bodyweight intramuscularly and maintained with ketamine by repeated 0.25 mg/kg bodyweight intravenous injections. The patient was intubated to allow mechanical ventilation and administration of oxygen if necessary. Lactated Ringer solution (Ringer Lattato; ATI, Italy) was administered intravenously at the dose of 10 ml/kg/h throughout the procedure. Electrocardiogram, respiratory rate, arterial blood pressure and haemoglobin saturation with oxygen were monitored during anaesthesia.
A urinary catheter was placed in order to keep the bladder emptied of urine, this to avoid bladder injury during trocar insertion, to move more freely the surgical instruments and to allow appropriate inspection of pelvic abdominal structures. The catheter was maintained until recovery from anaesthesia. After the abdominal area had been clipped and surgically prepared, the patient was placed in dorsal recumbency on the operating table with the head tilted down at 15° and the pelvic limbs toward the endoscopy monitor (Trinitron, Sony, Japan). A 3 mm trocar (Endopath, Ethicon Endosurgery, USA) was inserted into the abdominal cavity in a right para-umbilical position through a small stab incision of the skin. During insertion the trocar was directed toward the pelvis to avoid injuring the spleen. The obturator was removed and a 3 mm, 30° laparoscope (Hopkins, Karl Storz, Germany) connected to an electronic light source (Xenon Nova, 175 Watt, Karl Storz, Germany) and a video camera system (Telecam SL, Karl Storz, Germany) was inserted through the cannula in order to ensure that the peritoneal cavity has been entered. The abdominal cavity was insufflated with carbon dioxide by means of an automatic insufflator (2232, Richard Wolf, Germany) connected to the trocar. Intra-peritoneal pressure was maintained at 11 mmHg by the automatic insufflation device. The abdominal cavity was then explored and the testicles were readily identified adjacent to the urinary bladder. Under laparoscopic visualisation, two additional 5 mm trocars (Endopath, Ethicon Endosurgery, USA) were placed. The proposed trocar sites were transilluminated to help identify vessels in the abdominal wall so they could be avoided during trocar insertion. The first trocar was inserted through a small skin incision about 2–3 cm lateral to the midline and halfway between the umbilicus and pubis. The second one was inserted at the same level, but on the contralateral side. The first testicle was localised and grasped with atraumatic forceps in order to tighten the gubernaculum testis. Approximately 5 mm of gubernacular tissue was cauterised by means of a bipolar forceps and cut with scissors. A similar procedure was used for the spermatic cord. The testicle was removed from the abdominal cavity through one of the two 5 mm cannulae. The second testicle was localised and removed using the same technique. The abdominal cavity was then explored again, to ensure the safety of haemostasis and to inspect abdominal structures for signs of injury, before desufflating the abdomen and removing the three cannulae. The small incisions were sutured with a 4–0 polydioxanone suture (PDS, Ethicon, USA) in a simple interrupted pattern. Atipamezol (Antisedan; Centralvet-Vetem, Italy) was administered, intramuscularly at the dose of 125 μg/kg bodyweight, at the end of the procedure that lasted approximately 20 min. The patient recovered uneventfully from anaesthesia and no clinical complication was observed.
To the authors' knowledge this is the first report of use of laparoscopy for the treatment of cryptorchidism in cat. A 3 mm abdominal incision (first port) allows locating retained testicles. Testicles can be easily localised exploring the abdominal area between the caudal aspect of the kidney and the internal inguinal ring or tracing the ductus deferens cranially to the testicle. If necessary, the operating table can be tilted from side to side to enhance testicle exposure. In this study a 30° laparoscope was used, which can certainly help the surgeon to localise the testicles, however a 0° laparoscope can also be used. The 0° scope provides the surgeon with a visual field that is in line with the true field; the 30° scope enables the surgeon to look over the top of tissue and into recesses, to observe a larger area by rotating the scope, and helps to keep the scope out of the way of the operative instruments. Some authors recommend the use of the Veress needle to establish pneumoperitoneum (Pena et al 1998, Petrizzi et al 1998). The needle is usually inserted beside the umbilicus and when the peritoneal cavity is properly insufflated, is removed and the first trocar is inserted. The 3 mm trocar (the diameter is only 1 mm superior to the needle's one) is inserted in the same manner as the Veress needle, it is used to establish pneumoperitoneum and serves as the primary port. This technique allows shortening operating time without additional risks. The technique described is similar to that used for laparoscopic castration of cryptorchid dogs but there are some differences. In dogs, trocars with larger diameter (10/12 mm) are usually employed to allow extraction of the testicle through the cannula; haemostasis of spermatic cord is achieved with endoscopic clips or endoloop (Freeman & Hendrickson 1999), while in cats it can be achieved with bipolar cauterisation because the vessels and ductus deferens are smaller. In human medicine the fundamental advantage of minimally invasive surgery over open procedures have been demonstrated: less post-operative pain, fewer intra-abdominal adhesions, fewer wound complications, reduction of tissue trauma (O'Riordain et al 1994). Several reports demonstrate that laparoscopic surgery may be superior to ordinary open surgery also in the veterinary field (Minami et al 1997, Gallagher et al 1992, Petrizzi et al 1998). On the other hand, laparoscopy presents some disadvantages such as expense of surgical equipment, need for qualified experience, risk of anaesthesiology complications due to pneumoperitoneum and Trendelenburg position. Posture and carbon dioxide (CO2) insufflation, with associated increases intra-peritoneal pressure (IAP) and CO2 absorption, may lead to a significant rise in arterial partial pressure of CO2 (PaCO2) and to a fall in arterial partial pressure of oxygen (PaO2) in endosurgical patients. For this reason these parameters should be monitored. Also parameters of ventilation (tidal volume, peak inspiratory pressure, minute volume) should be monitored. Intra-peritoneal pressure more than 15 mmHg may also reduce cardiac output and abdominal organ perfusion. However applying the ‘rule of 15's’ (15 mmHg IAP and 15° tilt up or down) when insufflating the abdomen should be within safe limits for normal animals (Bailey & Pablo 1999). This report shows that laparoscopic cryptorchidectomy can also be successfully and quickly performed in cats. The testicles were easily found and removed without complications and the operative time was relatively short.