Asymptomatic Diaphragmatic Herniation, a Post-Traumatic Finding: A Case Report

Diaphragmatic Hernia (DH) is a condition where the abdominal contents protrude through a defect in the diaphragm muscle into the thorax. This can be caused by congenital or acquired factors like trauma. Post-Traumatic Diaphragmatic Hernia (PTDH) is a rare but potentially lifethreatening complication of trauma that can occur after a blunt or penetrating injury to the chest or abdomen. The incidence of traumatic diaphragmatic hernia is 0.8%-1.6% in patients admitted to the hospital for blunt trauma, 69% are left-sided, 25% are right-sided and 15% are bilateral [1]. PTDH may not present with immediate symptoms and can be difficult to diagnose. The delayed onset of symptoms, coupled with the rarity of the condition, can make PTDH difficult to recognize and diagnose, leading to delays in treatment and potentially serious complications [2]. Diaphragmatic injuries should always be considered in patients who have sustained thoracoabdominal trauma or polytrauma. Belated recognition of PTDH can result in potentially fatal outcomes, including respiratory distress, bowel obstruction, and sepsis [2-5]. Therefore, it is important to consider PTDH as a potential complication of trauma, even in the absence of immediate symptoms, and to promptly investigate any suspicious findings on diagnostic imaging.

A 27-year-old male patient attended the hospital six hours after suffering a vehicle accident. The patient was the driver of the vehicle and was wearing a seat belt at the time of the accident. According to a relative, the patient lost consciousness after the impact on the driver’s side, without the activation of airbags. Past medical history was negative for any significant medical conditions. On physical examination, a hematoma was found in the left parietotemporal region and a superficial abrasion. In addition, the patient presented pain on movement of the neck and pain on palpation in the cervical region. In the thorax, stigmata of trauma were found in the right infraclavicular region with decreased breath sounds in the left lower area, but remained normally dynamic and normally expandable, without inter or subcostal retractions or deformities. He also presents with tenderness to both superficial and deep palpation in the right hypochondrium and flank region. Symmetry, normal mobility, and pulses were present in the upper and lower extremities. On neurological evaluation, the patient was drowsy, oriented to person but disoriented in time and space.

The patient’s laboratory results showed elevated WBCs with neutrophilia, and mildly decreased lymphocytes and monocytes. Lactate dehydrogenase levels, serum glucose, procalcitonin, total bilirubin, AST and ALT levels were slightly elevated, while total CK was significantly elevated. He showed prolonged PT and INR with normal aPTT. The patient also had slightly decreased albumin levels (Table 1). Hemoglobin and hematocrit values were within normal range, as were platelets, creatinine, sodium and potassium. Early detection and treatment of PTDH can significantly improve patient outcomes and reduce the risk of serious complications [5]. Here, we present a case of an incidental finding of a diaphragmatic hernia on imaging performed in the emergency room after a traumatic event, without any symptoms related to the hernia. Normal range, as were platelets, creatinine, sodium and potassium. The thorax, abdomen and pelvis non-contrast-enhanced Computed Tomography (CT) scan revealed the gastric body located in the left hemithorax passing through a diaphragmatic defect, associated with the collapse of the left lung’s lower lobe (Figure 1). The CT scan was examined thoroughly by multiple radiologists, but no other abnormalities were found. We continued the evaluation of our polytraumatized and stable patient according to the protocols with a brain and cervical spine CT scan that shows no significant findings. The patient was admitted to the ICU with the diagnosis of polytrauma: mild traumatic brain injury, chest trauma with left lung collapse and closed abdominal trauma.

Table 1.Admission laboratory studies.

Figure 1:Thorax, abdomen and pelvis non-contrast-enhanced Computed Tomography (CT).

The urine output was monitored hourly with a Foley catheter and a central venous catheter was inserted for better hemodynamic management and drug administration. After 24 hours in the ICU, the patient remained hemodynamically stable, with no fever, respiratory distress, or other complications. We ordered a double contrast-enhanced Computed Tomography (CT) scan of the thorax and abdomen, which revealed the presence of a diaphragmatic rupture measuring approximately 7.36cm in a sagittal view and 8.05cm in a coronary view (Figure 2). This study compared to the previous one, showed left hemidiaphragm elevation with herniation of mesenteric fat, small bowel loops, gastric chamber, transverse and descending colon. The left lower lobe of the lung was atelectatic with diffuse interstitial opacity, suggestive of pulmonary contusion. The rest of the structures were normal. After the diagnosis was confirmed, we prepared for surgery with the appropriate preoperative measures (antibiotics and thromboprophylaxis) and he underwent a laparotomy.

Figure 2:Thorax, abdomen and pelvis contrast-enhanced Computed Tomography (CT).

Surgical description

We made an 8cm medial supraumbilical incision. Once in the abdominal cavity, we observed abdominal organs protruding through a defect. We reduced it back into the abdominal cavity and observed a 7.36-8cm Diaphragmatic Rupture (DR). After exploring the cavity no signs of traumatic bleeding were found. Surprisingly, the spleen remained intact and unmoved with no lacerations or associated vascular lesions. The rupture was then repaired in two planes with non-absorbable sutures: first with interrupted cruciate sutures and second with continuous sutures. Also, a biologic mesh was used to reinforce the repair (Figure 3). The mesh was securely placed over the defect and anchored to the surrounding tissues.

The abdomen was thoroughly inspected to ensure no additional injuries were present and the incision was closed in layers. The patient’s condition remained stable during the procedure and no complications were noted.

Figure 3:Surgical photographs showing the diaphragmatic hernia defect before and after repair.

Post-operative

The patient was extubated and transferred to the recovery area, where he remained stable and was closely monitored. The nasogastric tube was removed the same night of the surgery and an oral liquid diet was initiated without any complications. The patient tolerated it well and showed no discomfort or adverse reactions. The Foley catheter remained in place overnight. We initiated respiratory therapy and deep breathing exercises to prevent potential respiratory complications. On the second day following the surgical intervention, the patient underwent a radiograph of the thorax, revealing a possible pleural effusion. A scan was performed, which confirmed the diagnosis (Figure 4).

Figure 4:Radiograph and non-contrast-enhanced Computed Tomography (CT) of the thorax and abdomen.

We inter-consulted the cardiothoracic surgery department for a chest tube placement. The patient’s oral intake was changed to a soft solid diet without any associated complications. On the third day post-op, the patient underwent a diagnostic thoracentesis of the left hemithorax. The procedure drained 10cc of amber-colored fluid, prompting an incision for pleurostomy with prior infiltration of 2% lidocaine at the level of the fifth intercostal space. A 12 French (Fr) pleural catheter was then inserted and connected to a chest drainage system with negative pressure, that collected 120cc of amber-colored fluid. We fixed the tube with a 2/0 silk suture, covered the site with sterile dressing, took a sample and left it to suction. We conducted a follow-up chest X-ray to evaluate the positioning of the chest tube, which demonstrated successful placement.

At 12 hours after minimal thoracostomy with a left pleural catheter and a total drainage of 300cc of serohematous fluid, the patient was evaluated by the thoracic surgery team. A CT scan was performed and revealed a persistent pleural collection despite drainage. As no more fluid was draining, the placement of a larger chest tube was considered. The case was discussed with the treating surgeon and a decision was made to reposition the chest tube with a 28Fr catheter. At the time of the event, the patient reports dyspnea when lying down and pain at the drainage site. On the patient’s 7th day of hospitalization, which was the 4th postoperative day after exploratory laparotomy with diaphragmatic closure, the 2nd day after chest tube placement and the 1st day after chest tube replacement with a total collection of 400cc of serohematous fluid, no complications were observed during the shift. As a result, a follow-up chest X-ray was performed, which showed successful drainage of the pleural effusion (Figure 5). Consequently, the decision was made to remove the chest tube and discharge the patient. The patient was discharged home with instructions for a gradual return to normal activities and follow-up consultation with the surgical team.

Figure 5:Radiograph of the thorax showing improvement concerning the pleural effusion.

On the 10^th day after the patient’s discharge for postoperative follow-up control of laparotomy with diaphragmatic closure, the wounds were found to be in good condition and the sutures were removed. The patient was then scheduled for a follow-up appointment in one month’s time.

Diaphragmatic injury caused by a blunt trauma to the abdomen, as is supposed in this case, is a rare occurrence, accounting for less than 1 percent of all traumatic injuries and less frequent than penetrating injuries which account for approximately 65 percent of all diaphragmatic injuries [3,4]. The diaphragm is often injured alongside other thoracic and abdominal organs which wasn’t the case in this patient pointing to a spontaneous diaphragmatic rupture, which can occur due to pre-existing diaphragmatic weakness or defects [5]. These defects can be a posterolateral, Bochdalek-type (accounts for approximately 70% of the cases); an anterior, Morgagni-type (accounts for approximately 27% of the cases); and a central tendon hernia, septum transversum-type (accounts for approximately 2%-3% of the cases) [6].

Given the location of the rupture in this patient if a pre-existing diaphragmatic weakness was present before the trauma, it is denominated a central tendon hernia, septum transversum-type, specifically in the left hemidiaphragm [6]. Even though some data points to this alternate cause, the most important fact in this case is the trauma history; making the case classified as a Post-Traumatic Diaphragmatic Hernia (PTDH). While some diaphragmatic injuries may be evident, such as herniation of abdominal contents on chest radiographs, others may not be easily detectable and imaging studies may not provide conclusive results. It is crucial to maintain a high level of suspicion, as a delayed diagnosis can lead to an increased risk of herniation and strangulation of abdominal organs, which can be life-threatening. Diagnostic laparoscopy, thoracoscopy, or open surgical exploration may be necessary to establish the diagnosis for patients in whom the diagnosis is uncertain. When identified, diaphragm injuries are typically repaired with open surgical or minimally invasive techniques, depending on the presence of associated injuries and the overall condition of the patient [5].

Like this case presentation, traumatic injuries to the diaphragm may not immediately manifest symptoms or signs [5]. In some cases, the presence of other severe injuries may lead to a delayed evaluation for diaphragmatic injury [5]. Over time, the diaphragmatic defect caused by trauma tends to increase in size, and there is a greater risk of herniation of abdominal organs, particularly on the left side which was the case in the patient with greater size of lesion and more abdominal organs being herniated [5]. In a small study on delayed diagnosis of traumatic diaphragm rupture, 3 out of 16 patients (19%) had their injuries missed during initial laparotomy [7]. Most of these injuries (15 out of 16) were found on the left side, while this was the case in this patient the diagnosis was done in time and delayed diagnosis-type complications were prevented [7]. The American Association for the Surgery of Trauma (AAST) has developed a diaphragmatic injury severity scale that classifies these injuries based on their severity [5].

Unlike some other organ injuries where higher injury grades correlate with increased morbidity and mortality, this relationship has not been established for diaphragmatic injuries [5]. The diaphragmatic injury severity scale includes five grades: grade I-contusion, grade II-laceration ≤2cm, grade III-laceration 2 to 10cm, grade IV: laceration >10cm; tissue loss ≤25cm², grade V-laceration and tissue loss >25cm² [5]. Based on the available data, the patient in this case was found to have a grade III injury severity (7.36-8cm), which was not associated with mortality and had a low morbidity rate. These findings can be helpful for future research to determine the correlation between injury grade and these important clinical measures.

In patients like this one, additional evaluation may be necessary beyond initial imaging studies during trauma evaluation based on the mechanism of injury and physical exam findings [5]. If there are trauma mechanisms that apply large amounts of force to the anterior abdomen and the auscultation of bowel sounds or nasogastric suction over the left thorax, then traumatic diaphragmatic injury should be immediately considered as a potential injury impacting the patient [5]. Although Computed Tomography (CT) is often used to rule out life-threatening injuries (e.g., traumatic aortic rupture) during the trauma evaluation, it may coincidentally lead to the diagnosis of diaphragmatic injury. However, even with advanced imaging techniques, small tears may not be visible. There are several signs on CT imaging that can help establish the diagnosis of traumatic diaphragmatic rupture. These include the discontinuous diaphragm sign, diaphragm thickening, organ herniation sign, dependent viscera sign, dangling diaphragm sign, collar sign, hump sign, band sign and contiguous injury on both sides of the diaphragm [8].

These signs can be helpful in establishing the diagnosis of traumatic diaphragmatic rupture and prompt early management which was the case for the organ herniation sign in this patient. According to Mallory Williams et al. [5] repair is typically required for all left-sided diaphragmatic injuries and some rightsided injuries when recognized [5]. Acute injuries are commonly repaired through an abdominal approach, similar to the method used for this patient. The amount of force required to cause blunt diaphragmatic injury is substantial, and while diaphragmatic injury can occur in isolation, it is frequently accompanied by other injuries that may necessitate repair [5]. In this patient’s case, we only detected diaphragmatic rupture with herniation of abdominal organs through a CT scan. However, the laparotomy was also conducted to detect any other trauma-related damage and conduct a management plan, apart from reducing and closing the PTDH. To manage patients with traumatic diaphragmatic rupture, an upper midline incision can be performed initially and extended, if necessary, for those who are hemodynamically stable and have undergone imaging that demonstrates only this injury and no fluid in the abdomen [5].

During abdominal exploration, downward traction on the fundus of the stomach and dome of the spleen is performed to visualize the left hemidiaphragm. It is also crucial to inspect the central tendon, the esophageal hiatus and the diaphragmatic crura at the aortic hiatus to ensure their firm attachment to the lumbar vertebrae without any tear. In cases of herniation of abdominal organs like this one, they should be gently reduced back into the abdominal cavity, although careful attention is given to avoid further injury to the spleen when it is needed. Is also acceptable to carefully extend the hernia defect to facilitate easier reduction of organs into the abdomen. To repair the injured diaphragm, the edges of the diaphragmatic defect are grasped with Allis clamps. This allows for better exposure of the injured diaphragm during suture repair and ensures the safety of thoracic soft tissue structures adjacent and superior to the suture repair. A permanent suture or absorbable monofilament suture (Size 0,1) can be used to repair the diaphragm in a running or interrupted fashion. During the placement of sutures, gentle downward traction of the cardiac surface of the diaphragm away from the heart is applied to avoid inadvertent cardiac injury. Surgeons often utilize mesh reinforcement to enhance the longevity of diaphragmatic repair and prevent future herniation. The mesh can be either synthetic or biologic and is typically sutured to the edges of the diaphragmatic defect, providing additional support to the weakened tissue. This approach has been demonstrated to lower the risk of recurrence and improve overall outcomes in patients undergoing diaphragmatic repair [9].

According to the National Trauma Data Bank (NTDB), patients with diaphragmatic injuries have an overall mortality rate of 25% [10]. Blunt diaphragmatic injuries are associated with higher mortality rates than penetrating injuries, likely because of significant associated thoracic or abdominal injuries [10,11]. In the NTDB study, patients with blunt diaphragmatic injury had a significantly higher mortality rate (19.8% versus 8.8%) than those with penetrating injuries [10]. Moreover, patients with blunt injury had significantly higher rates of pulmonary complications (14.8% versus 6.6%) and acute respiratory distress (7.4% versus 4.1%) compared to patients with penetrating injuries [10]. It is worth noting that mortality rates and associated complications depend on various individual factors, such as the extent of the injury and the presence of comorbidities and should be carefully considered on a case-by-case basis [5].

Reporting cases of PTDH due to a diaphragmatic rupture is important to raise awareness among healthcare professionals and to highlight the need for appropriate diagnostic imaging and followup in patients who have experienced significant trauma. Multiple previous references have underlined that PTDH can be an oftenmissed diagnosis for multiple reasons such as being overshadowed by other traumatic injuries, because of a possible delayed onset of symptoms, or because the initial diaphragmatic lesion was so mild that caused little to no findings on diagnostic imaging [1,2,4,5,7,10,11]. Missing the diagnosis of PTDH has been reported to be associated with multiple complications such as volvulus, incarceration, or strangulation of intra-abdominal viscera [1]. Therefore, ruling out the presence of PTDH could be an important step in the process of improving the management of polytrauma or thoracoabdominal trauma. Classifying PTDH according to the moment of diagnosis as either acute or chronic has been proposed. In both cases, traffic accidents have always been the most prevalent trauma mechanism and CT has been the most useful diagnostic tool. The main symptom described is dyspnea and other common symptoms might include nausea, chest pain, cough, and epigastric pain [2]. According to previous reports, respiratory symptoms are more common in the acute phase, and patients who ended up developing chronic PTDH had a lower injury severity score and a shorter length of diaphragmatic rupture [1].

The case presented here shares some of the most common features that are usually found, such as the lesion being on the left hemidiaphragm and having a traffic accident as the mechanism of trauma, it has a unique presentation, as even though the patient had a great a diaphragmatic rupture (8cm approx.), with herniation of major structures such as the gastric body, small intestine and part of the transverse and descending colon associated to a passive collapse of the left lung, the patient remained with no symptoms that could be associated to PTDH. Moreover, since this made the PTDH an incidental diagnosis found on imaging, there is still debate on whether the lesion was caused by the trauma, if it was a pre-existing condition or both in the form of a spontaneous diaphragmatic rupture due a site of weakness. The last one which would explain the lack of often associated thoracic, abdominal and pelvic injuries. This presentation underscores the importance of having in mind a PTDH when dealing with a thoracoabdominal trauma even if no clinical symptoms are present, while also providing insight into the potential complications or challenges that may arise during treatment, in order to improve the long-term outcomes of patients with this condition.

1. Gaine FA, Lone GN, Chowdhary MA, Lone H (2013) The etiology, associated injuries and clinical presentation of post traumatic diaphragmatic hernia. Bull Emerg Trauma 1(2): 76-80.
2. Spellar K, Lotfollahzadeh S, Gupta N (2022) Diaphragmatic Hernia. StatPearls.
3. (2023) In: Feliciano DV, Mattox KL, Moore EE (Eds.), Trauma. (9^th edn), McGraw Hill.
4. (2005) National Trauma Data Base. American College of Surgeons 2000-2004.
5. Williams M (2023) Recognition and management of diaphragmatic injury in adults.
6. Keijzer R, Puri P (2010) Congenital diaphragmatic hernia. Semin Pediatr Surg 19(3): 180-185.
7. Feliciano DV, Cruse PA, Mattox KL, Burch JM, Noon GP, et al. (1988) Delayed diagnosis of injuries to the diaphragm after penetrating wounds. J Trauma 28(8): 1135-1144.
8. Panda A, Kumar A, Gamanagatti S, Patil A, Kumar S, et al. (2014) Traumatic diaphragmatic injury: A review of CT signs and the difference between blunt and penetrating injury. Diagn Interv Radiol 20(2): 121-128.
9. Antoniou SA, Pointner R, Granderath FA, Köckerling F (2015) The use of biological meshes in diaphragmatic defects-an evidence-based review of the literature. Front Surg 2: 56.
10. Fair KA, Gordon NT, Barbosa RR, Rowell SE, Watters JM, et al. (2015) Traumatic diaphragmatic injury in the American College of Surgeons National Trauma Data Bank: A new examination of a rare diagnosis. Am J Surg 209(5): 864-868.
11. Williams M, Carlin AM, Tyburski JG, Blocksom JM, Harvey EH, et al. (2004) Predictors of mortality in patients with traumatic diaphragmatic rupture and associated thoracic and/or abdominal injuries. Am Surg 70(2): 157-162.