Subphrenic Abscess

SUBPHRENIC ABSCESS (syn. subdiaphragmatic abscess), any encapsulated accumulation of pus in the subphrenic space. In normal anatomical conditions, this space is the gap located between the lower surface of the diaphragm and the adjacent organs situated below it: the liver, spleen, stomach, and kidneys. Intra- and extraperitoneal subphrenic spaces are distinguished, as well as their right and left sections. The extraperitoneal subphrenic space, normally filled with cellular tissue, is located on the right side between the posterior edge of the diaphragm and the posterosuperior edge of the liver, and on the left side between the edge of the left lobe of the liver and the left dome of the diaphragm. The intraperitoneal subphrenic space represents spaces lined with peritoneum: on the right, between the lower surface of the diaphragm and the upper surface of the liver; on the left, between the same surface of the diaphragm and the left hepatic lobe, the adjacent section of the fundus of the stomach, and the upper edge of the spleen. The right and left sections usually do not communicate with each other, being separated by a partition running anteroposteriorly (ligamentum suspensorium hepatis). Posteriorly, these sections are separated from each other by the convexity of the spine. Anteriorly, the intraperitoneal subphrenic space passes directly into the free abdominal cavity; posteriorly, it is bounded by the ligamentous apparatus attaching the liver to the posterior abdominal wall, i.e., the falciform ligament in the middle section and the right and left triangular ligaments on the sides. When an abscess develops in the extraperitoneal subphrenic space, the peritoneal leaflet is gradually detached from the lower surface of the right or left dome of the diaphragm, and a purulent accumulation is formed between this surface and the posterior edge of one or the other hepatic lobe. Based on the anatomical relations and boundaries just indicated, it is not difficult to visualize the pathways of origin and spread of subphrenic abscesses. First of all, it must be borne in mind that these abscesses almost as a rule form metastatically, i.e., as a result of the penetration of infection into one or another section of the subphrenic space from organs and regions more or less distant, and are significantly less frequently formed in the subphrenic space itself primarily or from sources of immediate anatomical proximity. These latter forms are caused mostly by two reasons: hepatic abscesses located near the upper surface of the liver and opening directly under the diaphragm, and trauma. Left to themselves, hemorrhages during injuries are frequently infected either at the very moment of injury or later, which gives rise to the gradual development of a subphrenic abscess from a hematoma. The same fate can befall hemorrhages occurring after subcutaneous ruptures of the liver, spleen, and comminuted fractures of the lower ribs. This also includes those cases of splenic abscesses which, becoming encapsulated directly under the left dome of the diaphragm, sometimes develop as a result of relapsing fever, or more rarely typhus. Of subphrenic abscesses of local origin, extraperitoneal ones, developing in the retroperitoneal cellular tissue between the diaphragm and the posterior edge of the liver, most often have as their source purulent processes occurring in the kidneys or perirenal spaces, as well as purulent forms of appendicitis, mainly with a posterior retrocecal position of the appendix. Intraperitoneal subphrenic abscesses localized under the right or left dome of the diaphragm most often arise as a result of diseases of the stomach, appendix, biliary tract, and spleen. Most frequently, subphrenic abscesses occur after diseases of the stomach with the duodenum and appendicitis. In relation to retroperitoneal abscesses, the pathway of infection spread is the retroperitoneal cellular tissue itself with the venous and lymphatic system embedded in it. At the same time, a very essential factor in the mechanism of movement of infection, regardless of the area and place of its localization, is the constant suction function of diaphragmatic respiratory excursions, and on the other hand, the propelling role of intestinal peristalsis. Both of these moments contribute to the displacement of infection from the lower section of the abdominal cavity to the upper and create conditions for the localization of the abscess in one or another region of the subphrenic space. An equally essential role in this displacement belongs to the lymphatic and venous vessels. It is precisely through this lymphogenic pathway that infection is transmitted from ulcerous foci of the stomach. In cholecystitis, the infection spreads either through the surrounding cellular tissue and the hepatoduodenal ligament, or through the development of cholangitis with the subsequent formation of a liver abscess and its rupture under the dome of the diaphragm. In acute purulent forms of appendicitis, the process can spread in several ways: either directly along the retroperitoneal cellular tissue (paracolon), especially with a high retrocecal position of the appendix, or more often through the carriage of infected thrombi from the inflamed mesentery of the appendix, or frequently via a lymphogenic pathway along the cellular tissue (textus cellulosus) running along the ascending colon (see Retroperitoneal space). Already from the enumeration of etiological moments, it becomes clear that subphrenic abscess is more frequently encountered on the right. The bacterial flora found in the pus of a subphrenic abscess is extremely diverse. Most often, the colon bacillus in its various modifications is determined here, as well as Staphylococcus pyogenes, Bacillus pyogenes foetidus, certain types of saprophytes, lamblia, and others. Quite frequently, gas is found in the cavity of the abscesses, the origin of which is also diverse: sometimes it is a product of a given type of flora, sometimes the result of diffusion through a pathologically altered intestinal wall; sometimes gas gets directly from the perforated opening of an ulceratively affected stomach. Course. A subphrenic abscess arising in one way or another gives a very diverse and as a rule severe clinical picture. In the presence of one of the above-mentioned diseases in the patient—such as stomach ulcer, cholecystitis, appendicitis, and others—a more or less acute deterioration of the general condition may occur, accompanied by chills, high temperature, and pains of varying intensity in one or the other hypochondrium. Depending on the acuteness of the process and the virulence of the pathogen, the disease acquires either a stormy or a more sluggish course and develops into a definite symptom complex, and sometimes it plays out after a considerable interval of time after the subsiding of the attack of the primary affliction. Left to itself, the disease in the vast majority of cases ends in the death of the patients from diffuse purulent peritonitis, pleural empyema, or general sepsis. In some cases, the process proceeds more slowly and only gradually—over the course of 2-3 weeks—forms into a clearly expressed form of abscess. Intraperitoneal abscesses proceed most severely, giving in general no more than 30% recoveries in contrast to extraperitoneal ones, which give up to 70% recoveries. A subphrenic abscess can remain encapsulated for quite a long time and usually causes significant changes on the part of the adjacent organs and first of all displacement of the diaphragm and liver. The dome of the diaphragm, gradually stretching and rising, sometimes reaches the II or III rib, and the muscle of the diaphragm, becoming paretic, loses its contractility and ceases respiratory excursions. As the accumulation increases, the liver is displaced downward and often drops 4-5 fingers below the costal arch, but the spleen and colon are usually not subject to displacement. Inflammatory phenomena that play out in the thickness of the diaphragm almost as a rule spread to the diaphragmatic pleura and lead in approximately 28% of cases to pleurisy, less often dry, more often exudative, and this latter occurs in 18% in serous and in 10% in purulent form. According to statistical data, these pleurisies more often complicate abscesses on the basis of stomach diseases, less often after appendicitis and gallbladder inflammation. Along with pleuritic changes resulting from infection penetrating through the lymphatic vessels through the undamaged diaphragm, cases of direct perforation of the abscess into the pleural cavity or into the lung fused with the diaphragm are far from rare. Thus, perforation into the pleura is noted in approximately 12%, into the lung in 15%. This severe complication, sometimes arising quite suddenly, can lead to formidable phenomena of a rapidly developing pyopneumothorax with a characteristic picture, while upon perforation of the abscess into the bronchus, an abundant amount of purulent sputum is immediately expelled. Complications on the part of the pericardial sac in the form of pericarditis or perforation into the cavity of the pericardial sac are very rare—about 6%. The position of the heart itself, which changes so typically in pleurisy, in cases not complicated by subphrenic abscess usually does not change. The peritoneum is involved in the process in the form of serous or purulent peritonitis. Direct perforation of the abscess into the abdominal cavity is almost never observed. Peritonitis is encountered in serofibrinous (about 10%) and in purulent (15%) forms and, just as in the case of pleurisies, represents a complication of abscesses of appendicular and gastric origin. The expressed objective picture of a subphrenic abscess is usually accompanied by severe subjective sensations.

In intraperitoneal abscesses, there are diffuse pains throughout the abdomen with predominant localization in one or the other hypochondrium, increasing during respiratory movements, followed by shortness of breath and usually a high temperature, significant leukocytosis; complications with pleurisy or peritonitis produce phenomena characteristic of them. With an extraperitoneal location of the abscess, the pains are localized for quite a long time in the posterolateral region of the lower chest. Diagnosis. Since subphrenic abscesses are in the majority of a metastatic character, a most detailed possible anamnesis not only of the given acute disease, but also of the processes preceding it, acquires special importance. At the same time, the greatest attention should be focused on data revealing disorders of the stomach, appendix, biliary tract, or kidneys. Among objective signs, the most characteristic, almost specific ones are percussion data. Percussion of the chest determines dullness, the upper boundary of which gives a very typical line. This boundary rises in front to the level of the II-III ribs, while posteriorly it gradually descends, reaching the angle of the scapula, and further down towards the spine it drops even more. Thus, a curve convex upwards is obtained, the highest point of which falls anteriorly and laterally and lowers towards the spine and the sternum. This form of dullness is almost pathognomonic for subphrenic abscess and distinguishes it from free pleurisy, in which the highest point of the dullness line is located at the spine and from there descends obliquely and sloping towards the anterior chest wall. With a left-sided location of the abscess, dullness is detected in the area of the stomach and in Traube's semilunar space; between the dullness of the abscess and the cardiac dullness, a strip of pulmonary sound is usually determined, while the cardiac dullness usually retains its normal configuration, since the heart is not displaced at all or gives only some upward displacement. Simultaneously with percussion changes along the chest wall, a downward enlargement of the hepatic dullness is almost always noted, depending on the usually significant prolapse of the liver, especially in right-sided abscess. Along with percussion data, the most essential importance for the recognition of subphrenic abscess is held by X-ray examination data, in view of which every case, even remotely suspicious regarding subphrenic abscess, should be subjected to repeated X-ray fluoroscopy whenever possible. In this case, the following picture is usually obtained: a clearly visible high, often cone-shaped standing of the diaphragm, which at the same time remains motionless and does not participate in respiratory excursions. Below the diaphragm, between it and the underlying dense shadow, a gas bubble is determined in most cases. Below the diaphragm is a dense shadow merging with the shadow of the liver. Fluoroscopy also makes it easier than other methods to differentiate subphrenic abscess from pleural exudate: in the latter, below the pleural shadow, the diaphragm is outlined, giving typical respiratory excursions; the level of the exudate is also located characteristically, i.e., along an oblique line from front and bottom up and back to the spine. In addition, subphrenic accumulation usually gives an absolutely motionless shadow, while the pleural shadow fluctuates, changing its level with corresponding movements (lateral tilts) of the patient. In complications of subphrenic abscess with pleural effusion, the boundary between the supra- and subdiaphragmatic shadows is smoothed out. In such cases, to clarify the presence and nature of the accumulation, one has to resort to punctures in various intercostal spaces. These punctures, made above and below the diaphragm, can yield liquids of different quality (purulent and serous) at different levels. Among the less constant and reliable diagnostic signs, one must include tenderness of the lower intercostal spaces, as well as percussive ballottement of the liver. In a later stage of the process, there appears a protrusion of the lower section of the chest wall of the affected side, its immobility, widening of the intercostal spaces, edematous softening of the soft tissues, and protrusion of the epigastric region; sometimes it is even possible to determine deep fluctuation. Treatment. Left to their own course and unoperated cases of subphrenic abscess give from 95% to 100% mortality, therefore every case of subphrenic abscess regardless of its type and localization unconditionally requires urgent surgical treatment, the essence of which comes down to the earliest and widest possible opening of the abscess with the provision of sufficient outflow of contents. Touching upon the very nature of the operation, it is first of all important to note the need for extreme caution in the choice of method and all moments in view of those topographical conditions—the direct proximity of the pleura and peritoneum—in which the subphrenic abscess is located and which make the wounding of these cavities easily possible with all the severe consequences of their infection. The primitive method of puncturing the abscess initially used (Recamier, Bardenheuer) with subsequent narrow drainage or without it very quickly revealed its negative sides. Not providing the necessary outflow, the puncture at the same time created the danger of introducing infection into the pleural or abdominal cavity and, as experience accumulated, gave way to the rational method of layered incision and wide drainage of the purulent accumulation. All operational methods proposed for these purposes can be divided into two types—the transabdominal and transpleural routes. The transabdominal route assumes access to the abscess through an incision of the abdominal wall immediately below the costal cartilages with excision of the two lower ribs or without this resection. This method is applicable in cases where the diaphragm stands relatively low and where, according to fluoroscopy data, the absence of obliteration of the phrenicocostal sinus can be assumed with its low location. In another series of cases, where the main mass of the abscess is lowered downwards and reaches with its lower border almost to the navel and below, a simple incision of the abdominal wall against the background of dullness and the opening of the abscess, the membrane of which in these cases lies directly against the abdominal wall, is applicable. The transpleural route, first proposed by Roser in 1864, is preferably used in cases where obliteration of the phrenicocostal sinus and adhesion of the pleural leaves over a greater or lesser considerable extent has been established or assumed, i.e., when one can expect to operate outside the free pleura. This method is carried out either simply by incision of one of the lower intercostal spaces with subsequent dissection of the adjacent diaphragm, or, more often, sections of the IX–X ribs are excised, which opens a significantly greater space for opening the abscess and subsequent drainage. But the adhesion of the phrenicocostal sinus is far from a constant phenomenon, and when it is not adhered, the path to the subphrenic abscess lies through the free pleura. Here, in order to avoid severe infection of the pleura, the most rational method is Troyanov's method, which boils down to the fact that after excision of sections of the IX–X ribs along the axillary line, the pleura is opened and, in the absence of adhesions in it, the adjacent diaphragm is sutured to the now soft lateral chest wall. By this, it is possible to almost hermetically isolate the free pleural cavity and create a convenient environment for extrapleural opening of the abscess. Finally, in cases where an extraperitoneal posterior accumulation is suspected, it is appropriate to approach it with a posterior-lumbar incision at the very site of the marked abscess. The choice of one or another method is determined by the nature of the process and can be outlined only as a result of a detailed study and examination of each given case. Postoperative outcomes yield about 50–60% recovery. However, such a result, of course, can far from be considered satisfactory. At the same time, a significant difference in outcomes is revealed depending on the type of abscess (see above).