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Praca oryginalna Original paper
Diaphragmatic hernia refers to a protrusion formed by abdominal viscera into the thoracic cavity through abnormal openings in the diaphragm (3). It is known that most of diaphragmatic hernia cases (93%) are cau-sed by trauma while only a small portion of the cases develop spontaneously. The diaphragmatic muscle is frequently torn along the costal edges of the diaphragm at the ventral of the esophagus hiatus. The size and location of the slit in the muscle of the diaphragm determine which organs will pass into the thoracic cavity or become incarcerated in it. The abdominal organs that pass through and become incarcerated may have a varying degree of venous obstruction and con-gestion. The liver may produce an excessive amount of fluid which is transudat and extracellular in nature (8).
Traffic accidents with motor vehicles are the most frequent cause of traumatic hernias. However, any strong blow or impact such as falling from a higher place may also cause a diaphragmatic hernia. There is no known predisposition of race or genus for the occurrence of this type of hernia in cats. However, most of the herniated animals are at young ages (1-2-years--old), indicating a possible age predisposition. The progress of the disease may vary from hours to years. The reason for such a large variation is that the disease may not be diagnosed for a long period of time after the traumatic incident (7, 8).
Traumatic diaphragmatic hernias often occurs in cats. The most frequently observed congenital type of hernia is peritoneopericardial hernia (2, 3, 5, 10). The animals with diaphragmatic hernia are usually brought
to a clinic under shock associated with tachycardia, tachypnea/dyspnea, pale mucosal membranes, and oligourea. Cardiac arrhythmia is frequently observed and known as an important cause of morbidity. Other clinical findings vary depending on the organ(s) her-niated. They may include gastrointestinal, respiratory, and cardiovascular symptoms. The liver is the most frequently herniated organ and may result in hydro-thorax. The cause of hydrothorax includes venous obstruction and the squeezing of the organ. If a large portion of the stomach and intestines are herniated, the animal may look emaciated (3-5, 8).
Definitive diagnosis requires radiographic examin-ation. If there is a pleural effusion, thoracosynthesis must be conducted before the radiography. Loss of dia-phragmatic line and cardiac shadow, dorsal or lateral displacement of lung surfaces, presence of gas in the thoracic cavity and presence of small intestine or stomach filled with barium sulfate are characteristics of the diagnosis. In general, positive contrast celio-graphy may assist in diagnosis (1, 3-5, 9). A diaphrag-matic slit should be stitched by simple continuous stitches using an absorbable material such as polydiaxo-none or non-absorbable material polypropylene (3, 7, 8). The aim of this study was to determine the optimal anesthetic and surgical procedures in feline diaphrag-matic herniations.
Material and methods
A total of 44 cats (20 male, 24 female), at ages from 2 months to 3 years of age in different breeds were utilized. Initially the cats brought to our clinic after a trauma or with
Diaphragmatic hernia in cats: 44 cases
KURSAT OZER, OZLEM GUZEL, YALCÝN DEVECIOGLU, OZGUR AKSOY*
Department of Surgery, Faculty of Veterinary Medicine, Istanbul University, 34320, Avcilar, Istanbul/Turkey *Department of Surgical, Faculty of Veterinary Medicine, Kafkas University, 36040, Kars-Turkey
Ozer K., Guzel O., Devecioglu Y., Aksoy O.
Diaphragmatic hernia in cats: 44 Cases Summary
Diaphragmatic hernia is one of the most frequently observed injuries caused by trauma in cats. Study materials were a total of 44 cats (20 male, 24 female), at different ages (2-months-old to 2-3-years-old) from various breeds. Following direct radiography, positive-contrast radiography was also taken to confirm the diagnosis. General anesthesia was induced using 5% isoflurane inhalation. Following entubation, the anesthesia was continued using 1.5-2% isoflurane inhalation by a nonrebreathing system with a pediatric circle. When the repair was about to be completed, positive pressure was increased for treating atelectasis. The mortality rate in traumatic diaphragmatic hernia cases was found to be 6.8% at the end of the study. It was concluded in this study that the success of the surgery may be increased by effective anesthetic procedures.
Medycyna Wet. 2007, 63 (12) 1565
a complaint of respiratory difficulty were physically exa-mined. Following direct radiography, positive-contrast radiography was also conducted to confirm the diagnosis (fig. 1a-b, 2a-b). After the definitive diagnosis was perfor-med, routine heamogram and biochemical analyses were conducted and the general condition of the patients that did not require urgent care was stabilized.
A haemogram was conducted in 44 cases. Erythrocyte (RBC), haemoglobin (HGB), haematocrit (HCT), leuko-cyte (WBC) and thromboleuko-cyte (PLT) levels of the cases were evaluated. Biochemical tests were conducted in 12 of these cases as well. Aspartat aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamiltransferase (GGT) and creatine kinase (CK) levels of the cases were evalu-ated.
Oxygen was given for 10 min at the preanesthetic period using a mask. Meanwhile, venous access to intravenous injection was opened without causing irritation. Following this, general anesthesia was induced using 5% isoflurane (Forane® Likid, Abbott Laboratories, Istanbul, Turkey)
in-halation. After entubation, the anesthesia was maintained using 1.5-2%
isoflu-rane inhalation by a nonrebreathing sys-tem with a pediatric circle (BOC-Boyle International, Tur-key). The patients were prepared for surgery under gene-ral anesthesia (fig. 3). Abdominal regions of the patients were prepared for the surgery according to aseptic surgical principles after the positioning of the animals upwards. The abdominal cavi-ty was excised by median laparatomy. At this stage an assi-sted-ventilation was initiated. The her-niated organs were
pulled back using a wet-gauze. The slit on the dia-phragm was stit-ched by continuous stitches using 2/0 or 3/0 polyglactin 910 suture (Vicryl®
--Ethicon, Edin-burgh, UK) depen-ding on the size of the cat. During the repair of the dia-phragmatic slit, the assisted ventilation was continued at a 1 sec interval using 30% capacity of the lungs. When the repair was about to be comple-ted, positive pres-sure was increased to treat atelectasis. After elimination of atelectasis, the final stitch was inserted when the lungs were at complete expiration and then the pressure was de-creased. The opening of the laparotomy was closed accor-dingly. Isoflurane inhalation was ceased and oxygen was given until spontaneous respiration and a swallowing reflex began. Postoperative radiography was taken after extubation (fig. 4). During the postoperative stage, Carpro-fen (Rimadyl-Pfizer Limited, UK) was given at 4 mg/kg dose as an analgesic and antibiotherapy was applied for 5 days. The stitches were removed 7-8 days after the surgery.
Fig. 1a. A laterolateral direct radiography of a 2-year-old fe-male cat of mixed-breed
Fig. 1b. A direct ventrodorsal radiogra-phy of the same cat in figure 1a
Fig. 3. Inhalation anaesthesia with a pediatric circle in a cat Fig. 2a. A laterolateral positive-contrast celioghraphy of the same cat in fig. 1a-b
Fig. 2b. A ventrodorsal positive-con-trast celioghraphy of the same cat
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Results and discussion
The mean age of the cats was 10 months and varied from 2 months to 3 years. Twenty four of the 44 cats were female while the remaining 20 were male. The frequency of occurrence of diaphragmatic hernia was the highest in cross breed cats (39 cases) followed by Persian (3 cases) and Siamese (2 cases) cats.
The cause of the hernia was mostly trauma. In 4 of the cases, there were also fractures due to trauma (2 humerus, 1 femur, 1 tibia). All of the patients were brought to our clinic with the complaint of respiratory difficulty. Definitive diagnosis was made by the ra-diographic examination of the thoracic cavity. Other findings were dry-cough, anorexia, decreases in lung and heart sounds by auscultation, and the thinner appearance of the abdomen of the animals compared to the normal size of the cats abdomen.
In the laterolateral (LL) radiographies of the thorax, there were disappearances of the diaphragmatic border, presence of consolidation (pleural effusion) in 12 cases, and intestine with gas noted in 4 cases. The definitive diagnosis was made by positive contrast celioghraphy. In celiography it was observed that iodine contrast substance passed to the thoracic cavity several minutes after intra abdominal administration. The site of the hernia was determined by ventro--dorsal (VD) radiography.
Haemogram results indicated that anemia was pre-sent in very young cats (2-6 months and in both of the genders). Following biochemical analysis, an increase was determined in the levels of the liver enzymes AST, ALT and GGT, in 5 (3 females, 2 males) of the 12 cases. In the remaining 7 (4 females, 3 males) acute cases, on the other hand, a rise in CK levels was noted due to the destruction of muscle tissue.
It was observed that the liver was herniated in all of the cases. Additionally, stomach, omentum, and small intestines were among the most frequently herniated organs. The slit of the diaphragm was at the dia-phragm-costa attachment site in 30 cases (right site in 17, left site in 13 cases) and at the hiatus level in 14 cases. Thoracic fluid accumulation was noted in 12 of the cases due to venous stasis.
Three of the cases were lost during the operation, two of these deaths were due to a failure in removing the excessive secretion from the respiratory system and the other due to a slit of the lungs caused by the appli-cation of too much pressure during the elimination of atelectasis.
Diaphragmatic hernia is one of the most frequently noted cases caused by trauma in cats (3, 5, 7, 8, 10). In the present study, congenital hernia was not observed. In all cases, however, a history for trauma was exi-stent or signs of a recent trauma such as echimosis, wounds, and fractures were noted during the physical examination of the animals.
Although no known predilection was reported for diaphragmatic hernia in cats (3, 7), a great majority of our cases were cross breed cats (39 cases). As the gen-ders of the patients were evaluated, it was observed that the number of the female cats (24) was slightly higher than the male cats (20). The disease was more common among younger aged cats (10 months of age on average) which is consistent with the previous lite-rature (3, 5, 8).
Sick animals with a history of trauma and a compla-int of respiratory difficulty should be evaluated for dia-phragmatic hernia since these are the common symp-toms for this disease (3, 5, 8). Radiographic exami-nation, especially positive contrast celioghraphy, is strongly recommended for a definitive diagnosis (1, 3, 4, 8-10). However, it should be remembered that a diagnosis based on the passage of the contrasting substance to the thoracic cavity might be misleading if there are adhesions. In our study, we have only noted this in one case (fig. 5a-b).
Fig. 4. A laterolateral postoperative radiography of the same cat as in fig. 1
Fig. 5b. Positive contrast celiography of the same cat shown in fig. 5a
Medycyna Wet. 2007, 63 (12) 1567 The liver is the most frequently herniated organ and
usually considered responsible for hydrothorax cau-sed by the venous stasis of the organ. Fluid accumula-tion in the thoracic cavity was seen in 12 of the 44 cases in the current study. The increase in AST, ALT and GGT levels noted in 4 cases was thought to be a result of the liver being under pressure for a long time due to the chronic nature of the cases.
If the general condition of a patient is stable enough to allow surgery, the animal should be operated as soon as possible to prevent acute decompensation and po-tential lung edema that may develop postoperatively (3). However, it was reported that surgery within the first 24 h without stabilizing the patient may result in a higher mortality rate. Preoperative oxygen inhala-tion is essential for myocardial oxygenisainhala-tion and the prevention of acidosis (3).
Use of prednisolon is recommended for the preven-tion of reexpansion edema (3). As the use of predniso-lone was only a recommendation and since it was thought that this medication could have a detrimental effect on the healing of the wound, it was not conside-red to be suitable for use in this study. In this study, where thorax drainage was not essential (2, 3, 8) the procedure was not carried out post-operatively in any of the cases. No complication was observed within the follow up examinations of the first year.
Since cats with diaphragmatic hernia exhibit respi-ratory depression, they should not be anesthetized by combinations of preanesthetic (xylazine) and anesthe-tic (barbiturates) that may depress the respiratory sys-tem. Although the authors do not recommend using face masks for anesthetic induction (3, 6, 10), we have
not encountered any difficulty or complications. Mor-tality rates in traumatic diaphragmatic hernia cases vary from 12 to 48% (3, 7, 8). The mortality rate was 6.8% in this study, which is lower than the average.
As a result, in stabilized cat patients with diaphrag-matic hernia, the success of the surgery may be in-creased by anesthesia initiated by mask induction fol-lowed by the use of isoflurane via entubation.
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