Definition
- It means moving of an abdominal organ (spleen, stomach, Liver or intestine, etc.) into the thoracic cavity within abnormal opening in the diaphragm.
Causes
- acquired injury as a car accident or birth defect (congenital). The most common cause is blunt force trauma.
Signs
- Labored difficult breathing, Rapid movements of the abdomen, irregular heartbeats.
- If the herniated part is stomach or intestine, signs may be associated with vomiting, diarrhea and bloating.
** Diaphragmatic hernias occur most commonly in animals that are allowed to roam outdoor and in male dogs. The pressure of such an impact causes a tear in the diaphragm, allowing an internal organ to protrude through the rip.
** Cocker spaniel dogs and Himalayan cat breeds may be predisposed to be affected with congenital diaphragmatic hernia.
Clinical picture
(1) Respiratory manifestations signs are the leading signs presenting the traumatic diaphragmatic hernia. Patient shows dyspnea, tachypnea (rapid breaths and chest movements) and cyanosis (hypoxia).
(2) Empty abdomen when palpated with hands.
(3) Abnormal or completely absent of heart and lung sounds.
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Chest plain x.ray should be made in all cases of trauma because the animal affected with traumatic diaphragmatic hernia may show no respiratory symptoms even with the thoracic displacement of abdominal organs.
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Diagnosis:
besides the clinical signs, X.ray considered the main diagnostic imaging method for diaphragmatic hernia.
Compare between a normal chest x.ray and x.ray with diaphragmatic hernia: See (Fig. 1)
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Normal chest x. ray |
Traumatic Diaphragmatic Hernia |
| – Diaphragmatic line is clear.
– Chest is filled with air (Black). -Normal cardiac silhouette (Normal well defined outlines). – Well-defined lungs fields.
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– Diaphragmatic line is not clear.
– Chest has abnormal different radiographic intensities. – Loss of defined cardiac outlines (silhouette). – Displacement of lung fields and compression by herniated organ. -Herniated organ as intestine, liver or stomach could be seen in the thoracic cavity. |
A post-operative X.ray after herniorraphy should include: see (Fig. 2):
1. Free thoracic cavity from the herniated organ or parts seen in the preoperative x. ray.
2. Cardiac outlines begin to be well-defined.
3. Lungs are fully inflated with air (black) and fill the entire thoracic cage.
4. Diaphragm line could be defined.
Prognosis of Traumatic diaphragmatic hernia
-Patients with traumatic diaphragmatic hernia have a guarded prognosis. This is because of some life-threatening complications like respiratory compromise, concurrent injury and internal hemorrhage with development of hypovolemic shock.
-The timing of surgical intervention is critical and surgeon should deal with other possible complications like; hemothorax, gastric tympany and strangulation of viscera that may accompany traumatic diaphragmatic hernia.
-Because the central tendinous part is stronger than the paired costal, lumbar and sternal muscles of the diaphragm, tears usually occurs along the fiber orientation of muscles or at their attachment to the ribs.
-The most common organ to herniate is the liver. Left- sided hernias usually involve the stomach, spleen and small intestine, while, right- sided hernias involve the liver, small intestine and pancrease.
Recommendations when dealing with patient with traumatic diaphragmatic hernia;
– Don’t rush to carry out surgery. Anesthesia and surgical procedures put the patient under more stress. The most important, before surgery is decided, is to make your patient stable. Stability here means cardiovascular and pulmonary stability. The Hypovolemia and hypoxia must be alleviated.
– Intravenous fluid replacementg. saline-dextrose and oxygen therapy are strongly recommended preoperatively. Over-compensation is not needed at all.
-If the patient is suffering from hemothorax or pneumothorax, tube thoracotomy is indicated.
-Severely compromised patients can get worse with handling. Animal should be kept with minimal handling and restraint especially when taking the x. ray projections. That could be achieved by sand bags and clothes pins fixed to the neck scruff. It is advisable to hold the patient in upright position to allow prolapsed viscera to return to abdomen.
Considerations considering the anesthetic protocol when dealing with a patient with traumatic diaphragmatic hernia;
1. The animal is premedicated with Morphine and anesthesia is induced with diazepam ketoprofen combination administered to effect.
2.To obtain a rapid intubation, lidocaine spray could be used to decrease the laryngeal reflex.
3. Maintenance of anesthesia is achieved by isoflurane in a positive-pressure ventilation circle system (time-cycled ventilator with preadjusted 15 breaths per minute).
4. It is important to monitor the saturation of hemoglobin with O2 with the probe applied to the tongue.
5. After closure, number of breaths is adjusted to 10 times per minute followed by spontaneous ventilation and finally removal of the endotracheal tube if the animal is capable of self-ventilation.
6. Other postoperative medications that could be used are tramadol and
7. Stabilization of the cardiovascular system and respiratory system should be carefully considered before attempting anesthesia and surgical repair of diaphragm.
8. Thoracocentesis may be necessary before induction of anesthesia especially in case of pneumothorax or accumulation of fluids in the pleural cavity due to reduced lung capacity.
9. Arterial blood gas analysis is very important to identify the extent of hypoxia and respiratory acidosis.
10. Face mask or nasal Insufflation (preoxygenation for 10 minutes) should be provided during induction of anesthesia and during recovery if the animal suffers from respiratory compromise to overcome hypoxia and improves myocardial function.
11. Tranquilizers and analgesics should be administered before operation as relieving pain decrease the respiratory load. Also, Opioids and sedatives (like; Morphine) are generally indicated especially when the animal is experiencing moderate to severe pain after trauma.
12. After administration of PAMs, patient should be monitored carefully because most of those drugs make respiratory depression.
13. Phenothiazine and benzodiazepine tranquilizers have low effect on respiratory function at therapeutic doses.
14. The alpha-2 adrenergic agonists (e.g. xylazine, detomidine and medetomidine) should administered carefully or given in very low doses because it cause a bad effect on respiration especially when the animal has pneumothorax.
15. Injectable anesthetics (ketamine and Propofol) allowing rapid intubation are preferred.
16. Ketamine-diazepam combination could be used for anesthetic induction in patients with respiratory depression followed by lidocaine spray.
17. Rapid induction should be followed by tracheal intubation.
18. If a mechanical ventilator is not available, manual intermittent ventilation by reservoir bags is indicated. Higher inspiratory pressures should be avoided during ventilation either mechanical or manual, to prevent lung damage or excessive reexpansion of collapsed lungs.
19. Briefly, the anesthetic management of a patient with diaphragmatic hernia should include: careful preanesthetic monitoring, preoxygenation and getting rid of pleural space with Thoracocentesis, rapid anesthetic induction with patent airways, providing intermittent positive pressure ventilation and administration of supplemental oxygen therapy during recovery.
Postoperative care
(1) Avoid inflation and rapid reexpansion of the collapsed lungs because it could be fatal as it leads to pulmonary edema.
(2) Placement of chest tube used for slow removal of pleural air (pneumothorax) during surgery and postoperative period (4-5 days) is critical to fully reestablish negative intrathoracic pressure to help the animal backing to normal respiration.
(3) Patient with traumatic diaphragmatic hernia should be hospitalized after herniorraphy. Often patient will feel better and try to move a lot after operation and recovering from anesthesia. This has a worse effect on the postoperative prognosis and survival rate so, it is important to encourage rest and avoid activity during the post-operative period.
(4) Successful treatment of shock before surgery improves survival rates. Animals having surgery delayed for more than one year after the initial trauma may have a worse prognosis due to the presence of adhesions (fibrous attachments) to other organs or tissues.
Urgent surgical treatment is indicated in case of:
(1) Gastric herniation with tympany.
(2) Continous hemorrhage and Hypovolemia as in case entrapped liver or spleen (capsular bleeding inside the thoracic cavity).
(3) Intestinal strangulation of a segment of the intestine causing non-relieving pain.
The leading cause of postoperative mortality cases in cats is the reexpansion pulmonary edema.
Patients with traumatic diaphragmatic hernia expose high anesthetic risk so they should be stabilized first before surgery attempts.
Traumatic Diaphragmatic Herniorrhaphy procedure :
1. The most preferable approach is the midline laparotomy. Balfour retractors could be used with moistened sponges to improve visualization.
2. If the rent (wound or opening) in diaphragm is old, trimming or debridement may be needed.
3. Suture closure may be used only for closing the diaphragmatic rent but in case of insufficient wound edges, synthetic mesh could be used. Closing of the diaphragmatic wound could be done with simple Continous or simple interrupted technique using absorbable or non-absorbable suture material.
4. After reduction of entrapped organs and closing the diaphragmatic rent, the surgeon may expose difficulty when opposing the linea Alba at the end of surgery. Tight closure may lead to increased unwanted intraabdominal pressure or wound dehiscence. This could be alleviated by performing splenectomy to free more abdominal volume to facilitate laparotomy incision without excessive unwanted tension.
A case report
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** A 2 years old cat presented to clinic after being hit by a car. Physical examination revealed dyspnea, mild tachycardia and abdominal pain. The cat was in severe respiratory distress with marked abdominal effort. Lung sounds were reduced on both sides. Abdomen was tucked up “feeling empty” and hollow. Intravenous fluids were administered till obtaining a better condition of the cardiovascular and pulmonary system. ** Cat was restrained for thoracic and abdominal radiography. Lateral radiograph film showed complete loss of diaphragmatic line and cardiac silhouette. Abdominal organs were poorly identified. Lungs were completely radiopaque indicating the complete loss of air filling capacity of the lungs and Aerated lung volume was significantly reduced (Fig., 3).
** The case was diagnosed to be Traumatic Diaphragmatic Hernia. And decision was taken to perform herniorraphy once the patient was stable without hypovolemic shock. ** Patient received preoxygenation therapy immediately before operation and during the induction of anesthesia followed by intravenous fluids administration. Checking the radiograph prompted the surgeon to suspect liver and intestine herniation because of the right-sided herniation. ** Ventilation immediately gets better with oxygen saturation ranging from 79% to 90%. Thoracocentesis was performed by a catheter at the right 8th intercostals space to withdraw any pleural fluids accumulated in the pleural cavity. Thoracocentesis revealed significant amount of pleural fluids. After Thoracocentesis, animal got better oxygen saturation levels. ** After that, Mildline laparotomy revealed a large right-sided radial tear with herniation of most of the liver, spleen and intestinal loops. The herniated organs had a significant more lager size than normal. Correction of the hepatic and intestinal displacement was performed (Fig., 4).
** The rent in Diaphragm was closed with the using of both suture closure and mesh closure. Firstly, Non absorbable suture material used to close the rent in simple interrupted manner followed by placement of the synthetic mesh previously adjusted to the size of rent. The mesh was fixed to the ligamentous and muscular part of the diaphragm with simple interrupted stitches with non absorbable suture material (Fig., 5, 6).
** Larger size of herniated organs made it little more difficult to close the abdominal laparotomy incision but it was overcame without the need to make splenectomy or any other procedures. Abdominal midline closure was made routinely. X.ray was photographed directly after operation to assess the condition of the chest cavity (Fig., 7). ** Chest tube was inserted to be capable of withdrawing any residual air or fluids inside the chest pleural cavity. Rapid evacuation was avoided with withdrawal rate 4 times daily for two days (Fig., 6). Cat was kept in Care intensive units for two days supplied with oxygenation therapy and intravenous fluids. ** Follow up after two weeks from the operation revealed excellent results. The patient was capable of self respiration without any aiding methods. Also, cat was capable of most of activities. A Control x. ray was taken to assess the lung air filling capacity. Lungs were fully inflated with air with normal respiration (Fig., 7).
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