Gastrointestinal Devices

Stomach tubes and intestinal tubes are the most common devices of this category found in radiographs (fig.1,2,3,4 and 5). They are useful to decompress the stomach and small intestine, to permit the sampling of bowel contents and for providing an access to patient nutrition. Common complications associated with their use are perforation of the gastrointestinal tract, hemorrhage, inadvertent placement in the lungs and increased risk of aspiration. Gastrostomy and jejunostomy tubes, as the name indicates, can be placed either in the stomach or in the proximal jejunum. They are used in long-term or even definitive assisted feeding in patients with gastrointestinal obstruction or severe neuromuscular problems. They are placed surgically or combining endoscopic and percutaneous radiographic techniques (PEG – percutaneous endoscopic gastrectomy tubes). 

Fig. 1: 1 - Nasogastric tube (arrow) placed to permit gastric emptying in a patient with bowel obstruction. It is possible to see several air/fluid levels (arrowheads).

Fig. 2: 2 –Nasogastric tube: images (a) and (b) show two nasogastric tubes placed for the administration of liquids and enteric alimentation. Note the distal extremity (arrow) placed in gastric chamber.

Fig. 3: 3 – Jejunostomy tube (arrow) placed surgically in a patient that needs long-term enteric alimentation, because of an unresectable gastric neoplasm.

Fig. 4: 4 – Jejunostomy tube: images show a frontal (a) and lateral (b) radiograph of a jejunostomy tube in a child. One extremity has a device where the syringe will be coupled (arrow) and the other a device that prevents tube displacement (arrowhead).

Fig. 5: 5 – Colostomy: images (a) and (b) show colostomy (arrow) in two different patients with rectal neoplasm.

Some new surgical procedures and diagnostic tools created the need to recognize not so usual devices (fig 6, 7 and 8). 

Fig. 6: 6 - Gastric band: images (a), (b) and (c) show gastric band (arrow), placed by laparoscopy near the gastroesophagic junction, for the treatment of morbid obesity. It is connected to a subcutaneous port (arrowhead), which permits band calibration. Note that the port can have different aspects.

Fig. 7: 7 – Axial CT images of a gastric band (arrow), placed by laparoscopy near the gastroesophagic junction, for the treatment of morbid obesity.

Fig. 8: 8 – Enteroscopy capsule: images (a), (b) and (c) show obstructed enteroscopy capsule (arrow), in three different patients with inflammatory bowel disease. Patient examined in image (c) also as tubal ligation clips (arrowheads).

Genitourinary Devices

Many devices are used to assure the urinary outflow. Ureteral stents are the most common type of urinary stent (fig. 9 and 10). They are used to traverse an area of obstruction, caused by benign (e.g. obstructing calculi) or malignant disease. The most common design for a ureteral stent is the double pigtail configuration, one pigtail in the renal pelvis and another inside the bladder. They can be placed either percutaneously (antegrade fashion) or with cystoscopy (retrograde fashion).

Fig. 9: 9 – Ureteral stent (arrow) with a double pigtail configuration in a patient with ureterohydronephrosis. The proximal pigtail is located in the renal pelvis and the distal in the bladder. It is possible to see a calculus (arrowhead) in the right kidney and a staghorn calculus (star) in the left kidney.

Fig. 10: 10 – Ureteral stent (arrow) with a double pigtail configuration in a patient submitted to kidney transplantation. Note also surgical clips (arrowheads).

The Foley catheter (or indwelling bladder catheter) is one of the most universal medical device (fig. 11, 12 and 13), that are used to decompress a distended bladder, collect urine and monitor patient urine output. It consists in a tube with a balloon attached to its extremity that can be insufflated using sterile saline, sterile water or air, to keep the catheter in place. The balloon is not normally seen in radiographs unless is filled with air or contrast agent.

Fig. 11: 11 – Foley catheter: images (a) and (b) show two examples of Foley catheters in patients with urinary retention. Image (a) also shows some phleboliths (arrowhead).

Fig. 12: 12 – Foley catheter: on the left we can see the same image from figure 11 (a) with a Foley catheter and the phleboliths. On the right, a MRI image of the same patient showing the Foley catheter in the bladder (arrow).

Fig. 13: 13 – Foley catheter: CT image shows a Foley catheter wrongly positioned at vaginalis fornix.

 Nephrostomy tubes are usually indicated to permit external drainage of the renal collecting system in a patient with a high-grade urinary tract obstruction, to provide an access route for placement of a ureteral stent, to provide a route for extraction of a renal or ureteral calculus, to permit the treatment of a urinary tract infection, superimposed on a urinary obstruction, and of urinary tract leaks and fistulas. (fig. 14 and 15) 

Fig. 14: 14 - Nephrostomy pigtail catheter with the extremity (arrow) located in the renal pelvis, in a patient with severe obstructive hydronephrosis.

Fig. 15: 15 – Nephrostomy catheter: radiograph (left) and CT image (right) of nephrostomy Malecot catheter (arrow), with the extremity located in the renal pelvis, in a patient with severe obstructive hydronephrosis.

Intrauterine contraceptive devices (IUDs) are a very popular form of contraception, usually visible on radiographs (fig. 16, 17 and 18), and they are recognizable on ultrasonography (US) and computed tomographic (CT) images if one is familiar with their appearance. They usually have a “T-shape” appearance and should be located centrally in the uterine canal. There are two main types based on the substance they use as contraceptive: copper releasing devices or progesterone releasing devices. A possible complication is migration of the device through the uterine wall into the peritoneal cavity. 

Fig. 16: Fig 16 – Intrauterine contraceptive device: images (a) and (b) show the typical “T-shape” appearance of intrauterine devices in two different patients.

Fig. 17: 17 – Intrauterine contraceptive device: images (a) and (b) show a different model of intrauterine device, with flexible arms with spurs, giving it this characteristic appearance.

Fig. 18: 18 – Intrauterine contraceptive device: radiograph (a), MRI (b), US (c) and CT (d) showing an intrauterine contraceptive device (arrow), correctly placed in the uterine cavity.

Tubal ligation (fig. 19 and 20) and vasectomy are another common form of contraception. They may not have specific radiographic findings, but occasionally special tubal ligation clips can be evident, such as the now widely used Essure^® device. It is a small, expanding microcoil placed in the proximal portion of the fallopian tube that incites a benign tissue ingrowth, which anchors the device and permanently closes the fallopian tube.

Fig. 19: 19 – Intratubaric microcoils: images (a), (b) and (c) show intratubaric microcoils – Essure® (arrows) in three different patients. They are placed via hysteroscopy, in the proximal segment of the uterine tubes, inciting fibrosis and obstruction.

Fig. 20: 20 – Tubal ligation clips: images a and b show tubal ligation clips (arrows). They are placed via laparoscopy.

Pessaries have been used for a long time to treat vaginal or uterine prolapse (fig. 21). They are simple mechanical devices being placed in the most posterior aspect of the vagina around the cervix, supporting the prolapsed structure. Nowadays, they have been largely replaced by surgical treatment for uterine prolapse. 

Fig. 21: 21 – Pessary: images (a) and (b) show a pessary (arrow) used in a patient to treat a uterine prolapse. Image (b) is an amplified image of (a). Note also a prosthesis on the right femur.

Post-surgical and Draining Devices

Surgical sutures, staples and clips (fig. 22, 23 and 24) are common findings on postoperative images. The type used depends on the preference of the surgeon and the type of wound being repaired. Is not always possible to know the exact location of these devices, they can either be external (skin, subcutaneous tissue) or internal. But some surgical procedures leave recognizable signs such as cholecystectomy, vascular clips or major bladder surgery. Small surgical staples can also be seen after surgeries that involve internal anastomosis such as intestinal or lung anastomosis.  Surgical sponges may be recognized by the presence of radiopaque markers or when inadvertently left inside the patient by the presence of associated complications. 

Fig. 22: 22 –Surgical suture (arrow) following partial gastrectomy.

Fig. 23: 23 - Surgical suture (arrow) following anterior resection of the rectum. It is also possible to see many surgical staples in the abdominal wall (arrowheads).

Fig. 24: 24 - Surgical clips (arrow) at the upper abdominal cavity following cholecystectomy.

Surgical drains are used to remove fluid collections that could otherwise lead to an infection, abscess formation or wound breakdown (fig 25 and 26). 

Fig. 25: 25 - Surgical drains (arrows) located in the peritoneal cavity following a classic cholecystectomy. Surgical staples (arrowhead) are seen in the abdominal wall.

Fig. 26: 26 – Surgical drain: radiograph (a) and US (b) showing a surgical drain (arrow) draining an abscess located in the splenic cavity. Sagittal (c) and axial (d) CT images of a surgical drain (arrow) draining a hepatic abscess.

Biliary drainage catheters and stents are generally placed to relief of obstructive jaundice, mainly as a palliative procedure in the presence of unresectable malignancy (fig. 27, 28, 29 and 30). In less common situations they can be also used to treat benign strictures or for preoperative decompression of the biliary tree. They can be placed percutaneously, surgically, endoscopically or using a combination of these techniques. Biliary drainage can be internal (anterograde drainage) placing a stent from intrahepatic biliary tract to the duodenum, external (retrograde external drainage) to a bag or sump tube or both internal and external using a T-tube. 

Fig. 27: 27 - Metallic stent (arrow) located in the common biliary duct, in a patient with a peripheral cholangiocarcinoma and consequent obstructive jaundice.

Fig. 28: 28- Biliary stent and surgical drain: axial (a and b) and coronal (c) CT and respective MIP reformatted images (d) showing a biliary stent (arrow) going from the intrahepatic biliary tract to the duodenum, permitting an anterograde drainage of biliary content, in a patient with obstructive jaundice due to cholangiocarcinoma. It is also possible to see a catheter (curved arrow) draining a hepatic abscess.

Fig. 29: 29 –Biliary drain: image shows a T drain (arrow) located in the common biliary duct, permitting an external biliary drainage. Surgical staples (arrowhead) post classic cholecystectomy.

Fig. 30: 30 – Biliary drain: image shows two drains placed in a patient with obstructive jaundice. One is placed on the common bile duct (arrow) and the other on the pancreatic duct (arrowhead)

Vascular and Intraperitoneal Devices

Vascular stent placement (fig. 31) is a common treatment option for coronary heart diseases, peripheral artery disease, renal artery stenosis, carotid artery disease or in the treatment of abdominal aortic aneurysms. Angioplasty is sometimes used before stent placement reducing the vascular stenosis, allowing correct placement of the stent. Their use in major veins, for malignant and benign disease is also possible. 

Fig. 31: 31 – Endovascular stent: scout view of an abdominal CT study (a), showing an abdominal aortic endovascular stent (arrow) for the treatment of a large aneurysm. Radiograph (b) showing an iliac endovascular stent (arrow) used in the treatment of an atherosclerotic obstruction. Axial CT images (c and d) of an aorto-iliac endovascular stent (arrows) that assure correct arterial permeability.

Vascular grafts are usually used to treat severe atherosclerosis, vascular occlusions, vascular injuries or aneurysms. Two different techniques can be used when placing aortic grafts: one consist in an interposition graft with removal of the affect portion of the aorta and other with an inclusion graft with the aorta being wrapped around the graft.

Portosystemic shunting is a procedure for treatment of refractory bleeding from esophageal and gastric varices mainly in the presence of cirrhosis. Portosystemic shunting may be performed surgically, but placement of a transjugular intrahepatic portosystemic shunt (TIPS) (fig. 32) is often the preferred method of therapy. In these circumstances, a self-expanding metallic stent is deployed to form a bridge between a major portal vein and one of the hepatic veins. The stent may be visible on radiographs, CT, MRI and US, which can often be used to establish the patency and flow rate through the stent. 

Fig. 32: 32 – Metallic stent: Axial CT images showing the presence of a self-expanding metallic stent (arrow), bridging the right portal vein to the right supra-hepatic vein, in a patient with cirrhosis and refractory esophageal varices bleeding.

Continuous ambulatory peritoneal dialysis is a common method for treating chronic renal failure. The most common catheter used for peritoneal dialysis  (fig. 33) is the Tenckhoff catheter, which is composed of silastic and has multiple side holes. These catheters may be placed surgically or percutaneously, with the catheter tip typically being inserted into the retrovesical space in men and in the pouch of Douglas in women. The catheter has one or more cuffs in its trajectory through abdominal wall, they will induce inflammatory reaction to better secure the catheter and prevent retrograde infection into the peritoneum.

Fig. 33: 33 – Peritoneal dialysis catheter: images (a), (b) and (c) show catheters used for continuous ambulatory peritoneal dialysis, with their extremity (arrow) in the peritoneal cavity, in retrovesical position. Catheter on image (a) has a straight tip while catheters on images (b) and (c) have curled tips. Cuff from the catheter (arrowhead) at the abdominal wall.

There are many types of general-purpose infusion pumps (fig 34) to deliver liquid medications and intravenous fluids to patients through vascular or intrathecal route. Infusion pumps for instillation of intrathecal medication may overlie the abdomen and pelvis, although their catheters may ascend into the thoracic spine. 

Fig. 34: 34 – Infusion pump: frontal (a) and lateral (b) view radiographs of an infusion pump. The pump (arrow) is placed at the anterior abdominal wall. A catheter (arrowhead) extends from the pump to the medullar canal (curved arrow) where instillation of intrathecal medication is made.

Neurostimulators (fig.35), like infusion pumps, are more frequently implanted beneath abdominal skin. They are pacemaker-sized devices, mainly used in the treatment of chronic pain, that send electrical stimulation through a lead to electrodes implanted near the spinal cord or an affected peripheral nerve “blocking” the transmission of painful stimulus to the brain.

Fig. 35: 35 – Neurostimulator: frontal (a) and lateral (b) view radiographs of a neurostimulator placed at anterior abdominal wall (arrow). It is used in patients with chronic pain. Is connected to an electrode implanted near the spinal cord (curved arrow), emitting electrical stimulus that "blocks" the painful stimulus.

Ventriculoperitoneal catheters (fig.36) can be easily recognized by their characteristic appearance on radiographs, extending from the ventricular system of the brain through the anterior portion of the chest wall into the abdomen. They commonly drain into the lower portion of the peritoneal cavity. Despite not being possible to be ascertain of their proper function using only radiographs, some signs as excessively coiling, kinking, or inappropriate location of the catheter, (e.g., in the substance of the liver), should rise suspicious and the patient’s physicians should be promptly alerted.

Fig. 36: 36 - Ventriculoperitoneal catheter (arrow) in a patient with hydrocephaly and bifid spine (star), draining the cerebrospinal fluid to the peritoneal cavity. It is possible to see the extremity of a Foley catheter in the bladder (arrowhead).