Evaluation of the effects of nephrotomy on renal function in clinically normal cats

OBJECTIVE: To evaluate the effects of nephrotomy on renal function in clinically normal cats. ANIMALS: 20 specific-pathogen-free, 9- to 11-month-old female mixed-breed cats. PROCEDURE: Serum chemistry analyses, CBC determinations, urinalyses, microbiologic urine cultures, renal ultrasonography, abdominal radiography, and single-kidney and total glomerular filtration rate (GFR) determinations by use of renal scintigraphy and measurements of plasma disappearance of technetium 99m-diethylenetriaminepentaacetic acid were performed before surgery and at 3, 12, 26, 52, and 78 weeks after surgery in 10 cats that underwent unilateral nephrotomy and in 10 control cats that underwent a sham surgical procedure. RESULTS: Two cats (1 from each group) did not complete the study, and their data were eliminated from analyses. Unilateral nephrotomy resulted in a 10% to 20% reduction in mean single-kidney GFR, compared with that of nephrotomy contralateral control kidneys. However, mean total GFR in nephrotomy-group cats was not significantly different from that of sham-group cats. Over the 78 weeks of study, mean total GFR declined 34% and 40% in nephrotomy- and sham-group cats, respectively. Adverse events associated with nephrotomy included persistent microscopic hematuria, renal pelvis hyperechogenicity with distant shadowing on ultrasonographic evaluation, dilatation of renal pelves, and hydronephrosis. CONCLUSIONS AND CLINICAL RELEVANCE: Nephrotomy in normal functioning feline kidneys results in a modest relative reduction in renal function, compared with contralateral kidney controls, but has minimal effect on total GFR when compared with sham-operated control cats. However, any detrimental effects of nephrotomy may be magnified in cats with diseased kidneys, which may have little or no capacity for repair or compensation.     

The effect of nephrotomy on renal function and morphology in dogs

OBJECTIVE: To determine whether bisection or intersegmental nephrotomy adversely affects glomerular filtration rate (GFR) and whether bisection nephrotomy has less adverse effect than intersegmental nephrotomy. STUDY DESIGN: Dogs assigned to 5 groups of 3 dogs each, depending on time of euthanasia at postoperative day 1, 4, 8, 15, or 29. ANIMALS: Fifteen healthy adult intact female dogs. METHODS: Within 4 days of total and single kidney GFR measurements using technetium Tc 99m-DTPA, left intersegmental nephrotomy and right bisection nephrotomy were performed. The GFR measurements were repeated the day before dogs were killed except for the day 1 group. Histologic examination was performed on kidneys harvested from day 1, 4, 8, and 29 groups. Severity of lesions was scored on a 0 to 4 scale. Single kidney GFR was compared in each kidney before and after nephrotomy. Histologic and GFR changes were compared between bisection and intersegmental nephrotomy kidneys for each time period. RESULTS AND CONCLUSIONS: Three days after surgery, total GFR was increased from baseline by 176%, with no difference in percent change in single kidney GFR between intersegmental and bisection nephrotomy. By day 7, total and single kidney GFR were not different than baseline. Bisection nephrotomy caused more intrarenal hemorrhage and cortical infarction and inflammation than intersegmental nephrotomy. By 4 weeks, no significant histologic differences were observed between the 2 techniques. CLINICAL RELEVANCE: Neither intersegmental nor bisection nephrotomy adversely affected GFR. As intersegmental nephrotomy requires additional surgical manipulation and time, bisection nephrotomy is the technique of choice for nephrotomy in dogs.     

Effect of nephrotomy on renal function and morphology in normal cats

OBJECTIVE: To assess effects over 12 weeks of bisection nephrotomy on renal function, size, and morphology in cats. STUDY DESIGN: Controlled, randomized, blinded experiment. SAMPLE POPULATION: Ten adult female cats. METHODS: Glomerular filtration rate (GFR), determined by quantitative renal scintigraphy using (99m)Technetium-diethylenetriamine-pentaacetic acid, urinalysis, urine culture, and ultrasonographic measurement of renal size were performed preoperatively. Left or right nephrotomy (5 cats/group) was performed. Total and individual kidney GFRs were determined at 2, 28, and 84 days, ultrasonographic measurements at 28 and 86 days, and ultrasound-guided biopsy at 86 days. RESULTS: No significant differences in mean GFR and kidney size of operated versus unoperated kidneys were observed. Individual GFR and renal size of all except 1 cat remained within normal limits. Two cats had evidence of transient ureteral obstruction in the immediate postoperative period. No significant, generalized histologic abnormalities were observed. CONCLUSIONS: Bisection nephrotomy in normal cats does not adversely affect renal function or morphology during the initial 12 weeks. CLINICAL RELEVANCE: Bisection nephrotomy can be safely performed in normal feline kidneys without causing a significant deleterious effect on renal function. Studies in cats with pre-existing renal insufficiency are needed to ensure adverse effects would not occur in clinical cases where this surgical procedure is warranted.     

Effect of fenoldopam on renal function after nephrotomy in normal dogs

OBJECTIVE: To evaluate effects of fenoldopam on renal function in normal dogs subjected to bisection nephrotomy. In addition, effects of bisection nephrotomy on renal function in normal dogs were evaluated. STUDY DESIGN: Controlled, randomized, blinded experiment. SAMPLE POPULATION: Sixteen mixed-breed adult dogs. METHODS: Dogs were paired for sex, body weight, and approximate age and assigned to 1 of 2 groups: fenoldopam (F) or placebo (P). Baseline glomerular filtration rate (GFR) based on quantitative renal scintigraphy using (99m)Tc-DTPA, blood urea nitrogen (BUN), serum creatinine (SCr), urinalysis, and urine culture were performed before surgery. Left nephrotomy was performed via median celiotomy. Group F dogs were administered intravenous (IV) fenoldopam (0.1 microg/kg/min) for 90 minutes, whereas group P dogs were administered an equivalent volume of saline (0.9 % NaCl) solution for 90 minutes. Temperature, heart rate, respiration, direct arterial blood pressure, and urine volume were recorded during anesthesia. Renal function was assessed by measuring SCr, BUN, and GFR at 1, 21, and 42 days after surgery. RESULTS: There was no significant difference between groups in measured physiologic variables. No significant difference in GFR, BUN, or SCr between groups or between operated or control kidneys was detected. CONCLUSIONS: Bisection nephrotomy in normal dogs with renal arterial occlusion of 15 minutes and using a simple continuous capsular closure does not adversely affect renal function. CLINICAL RELEVANCE: Bisection nephrotomy, as described in this study, does not decrease renal function; perioperative administration of renoprotective agents is not necessary in normal dogs.     

Development of a technique for serial bilateral renal biopsy in steers

A biopsy procedure was developed to provide serial kidney samples from standing steers. Ten clinically normal steers were given intramuscular injections of gentamicin sulfate, 4 mg/kg body weight. Renal biopsy was performed at 5 separate times. After feed was withheld for 24 h, laparoscopic surgery was performed in standing stocks. Acepromazine, xylazine, and butorphanol were used for sedation and analgesia, and 2% lidocaine was used for local anesthesia. Two incisions approximately 2 cm long were made in the paralumbar fossa to allow for trocar introduction. The abdomen was insufflated with CO2 and, with endoscopic guidance, a biopsy forceps used to remove a kidney sample 2 to 3 mm in diameter, by either a left or a right abdominal approach. Each operation was recorded on videotape, and images were also captured with a digital medical device system. Respiration, heart rate, temperature, appetite, attitude, and postural positions were evaluated at 12, 24, 48, and 72 h after surgery. The 51 laparoscopic procedures provided 48 renal samples (approximately 100 mg each). The 1st and 2nd samples were from the right kidney, and the 3rd sample was from either the left or the right kidney; the 4th and 5th samples were from the left kidney. Adhesions made an approach from the right side difficult for the 3rd sample. No clinical changes were observed in 9 steers after the procedure. One steer died after the 3rd procedure owing to hemorrhage.     

Laparoscopic removal of gastric foreign bodies in dogs--comparison of manual suturing and stapling viscerosynthesis

This study was an attempt to evaluate the application of various laparoscopic techniques of removing foreign bodies from the stomach in dogs in comparison to conventional laparotomy. The research was conducted on two groups of 10 dogs each with clinically confirmed foreign bodies in the stomach. In case of all patients, a laparoscopic instrument, EndoBag, was used for the removal of the foreign body from the stomach and the abdominal cavity. Manual suturing with the use of Szabo-Berci suturing kit was used for the gastrotomy wound closure in group I. In group II, linear staplers were used for viscerosynthesis. All patients were subjected to radiological assessment of tightness of anastomosis. No significant differences between the quality of the performed stomach anastomosis were shown. Therefore, the competitiveness of an economical manual suturing in comparison with the very expensive mechanical suturing preferred in human surgery was confirmed. The described procedures of laparoscopic gastrotomy seem to be applicable for removing foreign bodies from the stomach in a clinical veterinary practice.     

Laparoscopic intestinal exploration and full-thickness intestinal biopsy in standing horses: a pilot study

OBJECTIVE: To assess a laparoscopic technique for equine intestinal biopsy. STUDY DESIGN: Experimental study. ANIMALS: Seven adult horses. METHODS: Food but not water was withheld for 36 hours before laparoscopy. In 3 horses (group A) standing, right laparoscopic access to different small intestinal segments was compared with ventral median celiotomy access. Inaccessible segments were identified at necropsy. In 4 horses (group B), the feasibility of obtaining full-thickness duodenal and cecal biopsies and any associated morbidity were evaluated. Biopsy specimens were collected during standing right laparoscopy using a 2-step procedure and intracorporeal suturing technique, and abdominal lavage was performed. Horses were monitored clinically and by abdominal fluid cytology and microbial culture, and repeat laparoscopy was performed on day 6. RESULTS: Standing right flank laparoscopy provided good observation of small intestinal segments and enabled manipulation of all but 15-20 cm of the duodenum and approximately 40 cm more ileum compared with ventral median celiotomy. Group B horses had no complications, no adhesions, and no bacterial growth from peritoneal fluid samples. None of the horses had signs of abdominal pain. CONCLUSION: A 2-stage intestinal biopsy technique performed during standing, right flank laparoscopy may be a safe alternative to exploratory celiotomy and biopsy in normal horses. CLINICAL RELEVANCE: Right flank laparoscopy allows biopsy of intestinal segments including duodenum and 50% more of the ileum than is accessible by ventral median celiotomy. This technique should be evaluated in clinical patients.     

Nephroliths and ureteroliths: a new stone age

Nephroliths may obstruct the renal pelvis or ureter, predispose to pyelonephritis, or result in compressive injury of the renal parenchyma leading to progressive chronic kidney disease. Indications for removal of nephroliths in dogs include obstruction, recurrent infection, progressive nephrolith enlargement, presence of clinical signs (renal pain), and patients with nephroliths in a solitary functional kidney. The most common indication for removal of upper tract uroliths in cats is ureteral obstruction caused by ureteroliths. Nonobstructive nephroliths in cats are not usually treated unless they move into the ureter resulting in ureteral obstruction.

The treatment approach to nephroliths and ureteroliths is different for dogs versus cats. Surgical removal of nephroliths or ureteroliths by nephrotomy and ureterotomy respectively is associated with potential for complications in more than 30% of cats treated by ureterotomy; therefore, minimally invasive options should also be considered. Extracorporeal shock wave lithotripsy (ESWL) treatment of nephroliths results in small “passable” stone fragments in most dogs, whereas ESWL does not work effectively in cats. Ureteral stents are effective for relief of ureteral obstruction by ureteroliths in both dogs and cats. Ureteral stents may be left in place long-term to relieve ureteral obstruction by ureteroliths. Post-operative morbidity and mortality are substantially lower for ureteral stent placement compared to open surgical ureterotomy in cats.     

Isobaric (gasless) laparoscopic liver and kidney biopsy in standing steers

The purpose of the current study was to investigate the suitability of an isobaric laparoscopic procedure, using a single port, for obtaining serial kidney and liver biopsy samples from standing steers. The samples were used in support of a pharmacokinetic tissue–fluid correlation study. Laparoscopic access was performed 3 times in each of 8 healthy Holstein steers, alternating from the right side to the left side and then to the right side again. The surgery was performed in standing stocks after the animals were given 3 doses of sulfadimethoxine sulfate intravenously and fasted for at least 18 h. Sedation and analgesia were achieved with acepromazine and xylazine. Lidocaine 2% was injected at the center of the paralumbar fossa (left or right), and an incision was made for introduction of a trocar–cannula assembly. Room air was allowed to enter the abdomen through the cannula at the time of insertion. Once the peritoneal cavity was reached, an operating endoscope was inserted. No pressurized insufflation was performed. A biopsy forceps was introduced into the operating channel of the endoscope to obtain a 100-mg kidney or liver sample. No complications were encountered. The 24 laparoscopic procedures provided 24 kidney and 16 liver samples. The results suggest that the isobaric (gasless) single-port laparoscopic technique is feasible for kidney and liver biopsy on standing steers. The procedure can be performed in a reliable and efficient manner in the sedated standing bovine.     

Hand‐assisted laparoscopic nephrectomy in a standing horse for the management of renal cell carcinoma

An 18‐year‐old Quarter Horse gelding was examined for haematuria of 6 weeks' duration. Rectal examination identified an enlarged left kidney and ultrasonographic examination of the kidney identified grossly abnormal renal architecture. Hand‐assisted laparoscopic nephrectomy was performed following laparoscopic exploration of the abdomen for metastatic disease. A laparoscopic stapling device was successfully used to transect and ligate the renal vasculature and ureter. Histopathological examination of the kidney identified renal cell carcinoma. A 7 month survival was documented following surgery. Unilateral nephrectomy should be considered a therapeutic or palliative procedure for horses with renal cell carcinoma.     

Laparoscopic Anatomy of the Llama Abdomen

Paralumbar laparoscopy was performed, caudal to the last rib, in seven llamas. All animals were anesthetized, instrumented, and placed in sternal recumbency. Systematic exploration was performed in six donated llamas dividing the abdomen into right and left, cranial and caudal quadrants. The main structures of diagnostic significance that could be observed from the right side were the parietal and visceral surface of the liver, diaphragm, first compartment of the stomach (CI), caudal aspect of the third compartment of the stomach (C3), pancreas, kidney duodenum, jejunum, and ascending colon. From the left side CI, varying lengths of jejunum, ileum, ascending colon, and spiral colon were identified. From both approaches the bladder, and in females the uterus and ovaries could be observed. All animals were necropsied immediately following the procedure. Gross examination of the abdominal viscera in the did not yield any abnormalities that had been missed by laparoscopic evaluation. Using a left paralumbar approach, one clinical case presenting with signs of acute abdominal discomfort was evaluated. A diagnosis was made of diffuse enteritis that was confirmed at necropsy. Because of the distensible nature of the South American camelid (SAC) abdominal wall, the small size of the abdominal viscera, and the freely mobile nature of most portions of the gastrointestinal tract a thorough examination was possible in all animals.     

A comparison of the effects of carbon dioxide and medical air for abdominal insufflation on respiratory parameters in xylazine-sedated sheep undergoing laparoscopic artificial insemination

AIMS: To determine if abdominal insufflation with medical air will improve oxygenation and ventilation parameters when compared to insufflation with CO₂ in xylazine-sedated sheep undergoing laparoscopic artificial insemination (AI).

METHODS: Forty-seven sheep underwent oestrus synchronisation and were fasted for 24 hours prior to laparoscopic AI. Each animal was randomised to receive either CO₂ or medical air for abdominal insufflation. An auricular arterial catheter was placed and utilised for serial blood sampling. Respiratory rates (RR) and arterial blood samples were collected at baseline, after xylazine (0.1?mg/kg I/V) sedation, 2 minutes after Trendelenburg positioning, 5 minutes after abdominal insufflation, and 10 minutes after being returned to a standing position. Blood samples were collected in heparinised syringes, stored on ice, and analysed for arterial pH, partial pressure of arterial O₂ (PaO₂), and CO₂ (PaCO₂). The number of ewes conceiving to AI was also determined.

RESULTS: Repeated measures ANOVA demonstrated temporal effects on RR, PaO₂, PaCO₂ and arterial pH during the laparoscopic AI procedure (p<0.001), but no difference between insufflation groups (p>0.01). No sheep experienced hypercapnia (PaCO₂>50?mmHg) or acidaemia (pH<7.35). Hypoxaemia (PaO₂<70?mmHg) was diagnosed during the procedure in 14/22 (64%) ewes in the CO₂ group compared with 8/23 (35%) ewes in the medical air group (p=0.053). Overall, 15/20 (75%) ewes in the CO₂ group conceived to AI compared with 16/22 (72.7%) in the medical air group (p=0.867).

CONCLUSIONS AND CLINICAL RELEVANCE: There were no statistical or clinical differences in RR, PaO₂, PaCO₂, pH, or conception to AI when comparing the effects of CO₂ and medical air as abdominal insufflation gases. None of the sheep experienced hypercapnia or acidaemic, yet 42% (19/45) of sheep developed clinical hypoxaemia, with a higher percentage of ewes in the CO₂ group developing hypoxaemia than in the medical air group. Based on the overall analysis, medical air could be utilised as a comparable alternative for abdominal insufflation during laparoscopic AI procedures.     

Effects of Carbon Dioxide Insufflation and Body Position on Blood Gas Values in Horses Anesthetized for Laparoscopy

The objective of the study was to describe the effects of carbon dioxide pneumoperitoneum and Trendelenburg position on arterial blood gas values in horses anesthetized for laparoscopy. The study design was a prospective case series using 14 healthy adult horses anesthetized for elective laparoscopic surgery. All horses in the study were maintained under anesthesia with halothane in oxygen with intermittent positive-pressure ventilation. A pneumoperitoneum of 15 mmHg or less was achieved with carbon dioxide, and horses were tilted to a 35-degree Trendelenburg position to allow the completion of laparoscopic cryptorchidectomy (n = 13) or ovariectomy (n = 1). Heart rate, mean arterial pressure, and arterial blood gases were recorded at six time intervals throughout the procedure. Results of the study indicated a pH that decreased and partial pressure of carbon dioxide (PaCO₂) and mean arterial pressure that increased over time and differed significantly from baseline during Trendelenburg position. Partial pressure of oxygen (PaO₂) was significantly lower than baseline after assumption of Trendelenburg position and did not improve on return to normal recumbency and abdominal pressure. As body weight increased, pH and PaO₂ decreased and PaCO₂ increased. We concluded that horses placed in Trendelenburg position have changes that are transient, with the exception of PaO₂. Heavier horses have a greater change in pH, PaCO₂, and PaO₂ than lighter horses during abdominal insufflation and Trendelenburg position. The changes incurred during CO₂ abdominal insufflation and Trendelenburg position are transient, with the exception of a decreased PaO₂. Heavy horses undergoing abdominal insufflation and Trendelenburg position should be closely monitored for critical cardiopulmonary values.     

Clinical Experience With Jejunostomy Feeding Tubes In 47 Small Animal Patients

The medical records of 39 dogs and 8 cats which had jejunostomy feeding tubes placed using modifications of a previously described surgical technique were retrospectively reviewed. Modifications included the addition of a suture to anchor the feeding tube to the jejunum, the use of a continuous circumferential suture to pexy the jejunum to the abdominal wall, and the placement of a skin suture that penetrated deep into the abdominal wall fascia. All tubes were placed during surgical treatment of a primary intraabdominal disease. Tubes were used for feeding from 1 to 41 days (average 9.7 days). Sixteen patients (34%) developed mild to moderate complications such as chewing at the tube, inadvertent tube removal, tube obstruction, and cellulitis around the ostomy site. Three patients (6%) developed severe complications associated with breakdown of the surgical site. The modified jejunostomy technique was effective for placement of jejunostomy tubes as a complementary procedure to exploratory celiotomy.     

Instrument associated complication of a laparoscopic ovariectomy

The case reported here describes the retrieval of the end of a pair of laparoscopic forceps that became separated from the instrument shaft during a laparoscopic ovariectomy. This case details the procedures used to locate and remove the foreign body from the abdominal cavity. No complications associated with the intra‐abdominal foreign body occurred and the mare was discharged the following day.     

Left- and right-sided laparoscopic-assisted nephrectomy in standing horses with unilateral renal disease

Objective— To describe a technique for, and outcome after, left‐ or right‐sided laparoscopic‐assisted nephrectomy in standing horses with unilateral renal disease. Study Design— Clinical report. Animals— Horses (n=3) with unilateral renal disease. Methods— Horses were sedated with detomidine (0.01 mg/kg intravenously [IV]) and levomethadone (0.05 mg/kg IV). Paravertebral anesthesia and infiltration‐anesthesia with 2% lidocaine were used to create a surgical field incorporating the 17th intercostal space and paralumbar fossa. Two separate, ipsilateral portals and a mini‐laparotomy were used. The perirenal peritoneum was horizontally incised (10–15 cm) using endoscissors and the incision digitally enlarged for manual dissection of the perirenal fat and kidney mobilization. The renal vessels and ureter were individually dissected, ligated, and transected under laparoscopic observation and the kidney removed. The perirenal and laparotomy peritoneal defects were not closed; and the laparotomy was closed in a multilayered fashion. The transverse abdominal muscle was apposed in a continuous pattern using 1 polyglactin 910, the subcutaneous tissue (simple continuous pattern) and skin (simple interrupted pattern) with 2–0 polyglactin 910. Results— Left (2) and right (1) sided laparoscopic‐assisted nephrectomy (1 nephrolithiasis, 2 hydronephrosis) was performed successfully. Sedation and local anesthesia was adequate for intraoperative immobilization and analgesia. No intraoperative complications occurred. Incisional seroma formation and fever occurred on days 3 and 4 in 1 horse and resolved with medical management. Conclusion— Laparoscopic‐assisted nephrectomy can be used for removal of the left or right kidney in standing horses with unilateral kidney disease. Clinical Relevance— To avoid risks associated with general anesthesia and to reduce surgical trauma, laparoscopic‐assisted nephrectomy can be performed in the standing sedated horse using a 2 portal technique and a mini‐laparotomy.     

Evaluation of laparoscopic adhesiolysis for the treatment of experimentally induced adhesions in pony foals

OBJECTIVE: To assess the efficacy of laparoscopic adhesiolysis in the treatment of experimentally induced adhesions in foals. ANIMALS: 8 healthy pony foals. PROCEDURE: Celiotomy was performed and adhesions created at the jejunoileal junction and at sites 0.5 and 1 m proximal to this junction, using a serosal abrasion method. Ten days after celiotomy, exploratory laparoscopy was performed. Laparoscopic adhesiolysis was performed in the treatment group only (4 foals, randomly selected). Thirty days after the exploratory laparoscopy, a final laparoscopic examination was performed, and the foals were euthanatized. The number and characteristics of abdominal adhesions were recorded during laparoscopy 10 and 30 days after celiotomy and during necropsy. RESULTS: At 30 days after celiotomy, the number of adhesions in the control group was significantly higher than the number in the treatment group. In the control group, all adhesions observed during the exploratory laparoscopy were still evident at the final laparoscopy and necropsy. In the treatment group, adhesions did not form again after separation. During final laparoscopy and necropsy, a focal adhesion between the omentum and site of the initial laparoscope portal was observed in 5 of 8 foals. CONCLUSIONS AND CLINICAL RELEVANCE: The serosal abrasion model is useful for studying abdominal adhesions in foals. Laparoscopic adhesiolysis was an effective technique to break down experimentally induced adhesions in the early maturation stage of formation in pony foals. Studies are required to investigate prevention of de novo adhesions at the laparoscope portal sites.     

Ventral Abdominal Approach for Laparoscopic Cryptorchidectomy in Horses

Objective —To report a ventral abdominal approach and a ligating loop technique for laparoscopic cryptorchidectomy in horses.
Study Design —Prospective.
Sample Population—Six horses, aged 1 to 5 years, with retained testes.
Methods —One laparoscopic portal and three to four instrument portals were used for ventral abdominal laparoscopic cryptorchidectomy. Laparoscopic instruments were used to maneuver and secure the testis through a ligating loop (modified Roeder knot) that was secured from outside the abdominal cavity. Only minimal enlargement of one instrument portal was used to remove the testicle.
Results —Three horses were bilateral cryptorchids, and three were unilateral (left side, two; right side, one) cryptorchids. Operative time, defined as the time from laparoscope insertion to removal, ranged from 20 to 25 minutes for unilateral cryptorchids and from 40 to 50 minutes for bilateral cryptorchids.
Conclusions —The reported technique allowed decreased tension on the tissues during ligation and removal of the testis from the peritoneal cavity. Improved observation of the abdominal cavity, ligation security, shortened patient confinement time, and minimally invasive technique are all considered to be benefits of laparoscopic cryptorchidectomy.
Clinical Relevance —Direct observation of retained testes and intraabdominal castration are distinct advantages of the use of laparoscopy in horses that have had previous unsuccessful surgical attempts, horses with unknown histories that have retained testicular tissue, or bilateral abdominal cryptorchids.