Renal pedicle torsion after simultaneous kidney-pancreas transplantation.

BACKGROUND: Simultaneous kidney-pancreas transplantation has become a recognized therapy for type I diabetes mellitus patients with diabetic nephropathy, neuropathy, and retinopathy. In the vast majority of these procedures, both grafts are placed intraperitoneally, which reduces posttransplant morbidity. Recently, in some of our recipients, we noted renal dysfunction related to complications of the renal pedicle. Our objectives in this study were to identify the cause of this renal dysfunction and to prevent its occurrence in future recipients. STUDY DESIGN: We undertook a retrospective chart review of simultaneous kidney-pancreas recipients who experienced renal dysfunction related to renal pedicle complications. RESULTS: We found four recipients with renal dysfunction related to renal pedicle torsion, diagnosed by serial ultrasound scans and kidney graft biopsies. Early diagnosis allowed salvage of three kidney grafts, but one was lost after late diagnosis. CONCLUSIONS: A high level of suspicion is needed to diagnose renal pedicle torsion. If simultaneous kidney-pancreas recipients have recurrent renal dysfunction, and rejection has been excluded, serial ultrasound scans with color flow Doppler examinations are needed. Once the diagnosis is made, a nephropexy to the anterior abdominal wall is indicated to prevent further torsion and save the kidney graft. We recommend prophylactic nephropexy of left renal grafts if the renal pedicle is > or = 5 cm long and if there is a 2 cm or more discrepancy between the length of the artery and the vein.

Venous thrombosis of pancreatic transplants: diagnosis by duplex sonography.

OBJECTIVE: Our objective was to determine whether elevated pancreatic transplant arterial resistive index (RI) and absence of venous flow correlate with pancreatic transplant venous thrombosis. MATERIALS AND METHODS: Thirteen episodes of surgically documented pancreatic venous thrombosis occurred in 175 pancreases that had been transplanted over a 3-year period. Duplex sonography was performed before surgical exploration in 11 cases. We retrospectively reviewed these 11 sonograms to determine whether blood was flowing in the veins and arteries of the graft. The RI was calculated from all pancreatic artery waveforms. We compared these arterial RIs and the presence or absence of venous flow with those of pancreatic grafts without venous thrombosis to determine sensitivity and specificity. RESULTS: In the venous thrombosis group, thrombosis occurred within 12 days of transplantation (mean, 3.5 days) in all 11 cases. Six cases of thrombosis (55%) occurred within 1 day. Arterial flow was detected within the graft in nine cases (82%) and in the stump of the donor artery between the graft and the recipient iliac artery in the two remaining cases. Antegrade diastolic flow was absent in all arterial tracings. Diastolic flow reversal was present in seven (78%) of nine grafts with detectable intrapancreatic arterial flow. Arterial RIs ranged from 1.00 to 2.00 (mean +/- SD, 1.27 +/- 0.29). Intrapancreatic venous flow was absent in all 11 cases. In the control group (43 examinations in 34 patients) RIs ranged from 0.46 to 1.29 (mean +/- SD, 0.72 +/- 0.18). Two of 43 arterial tracings had diastolic flow reversal (RI > 1.0). Venous flow was present in all examinations in the control group. A statistically significant difference existed between the RIs in the thrombosis group and the RIs in the control group (p = .0001). CONCLUSION: Reversal of diastolic flow in pancreatic transplant arteries is highly specific for detection of graft venous thrombosis during the first 12 days after transplantation. Our findings suggest that an RI greater than or equal to 1.00 and absence of venous flow, in combination, are highly sensitive and specific for the diagnosis of pancreatic graft venous thrombosis.

Effects of capsular contracture on ultrasonic screening for silicone gel breast implant rupture.

Unlike computed tomography and magnetic resonance imaging, ultrasound is an inexpensive test of potential use in detecting silicone gel breast implant (SBI) rupture. However, periprosthetic capsular contracture can make ultrasonic diagnosis of rupture difficult because the contracture-related radial folds inside the SBI can lead to a false-positive diagnosis of rupture. This study was conducted to determine the effects of capsular contracture on the ability of ultrasound to diagnose SBI rupture. Preoperative ultrasonic results of 122 SBIs were compared with surgical findings at the time of implant removal. The sensitivity and negative predictive values of ultrasound were lower in the presence of a contracted capsule (41.2% vs. 68.7%, p = 0.062; and 58.3% vs. 79.6%, p = 0.056 respectively). Ultrasound should be considered reliable in diagnosing SBI rupture only in the absence of a contracted capsule.

Refractory ascites: midterm results of treatment with a transjugular intrahepatic portosystemic shunt.

PURPOSE: To assess midterm results and examine factors associated with successful treatment of refractory ascites with creation of a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: In 50 patients with refractory ascites, TIPS creation was performed. Clinical and ultrasound follow-up were performed. Success was defined as survival with no further therapeutic paracentesis and decreased ascites. RESULTS: Mean follow-up was 11.6 months after the TIPS procedure. Major complications occurred in 16% of patients including intraperitoneal hemorrhage, refractory encephalopathy, and progression of liver and renal failure. Overall mortality was 60% (30 patients). In 23 (62%) of 37 patients not lost to follow-up, ascites was controlled successfully at 1-3 months. A bilirubin level greater than 3.0 mg/dL (52 mumol/L) and creatinine level greater than 1.9 mg/dL (170 mumol/L) were associated with treatment failure (86% treatment failure at 3 months) and early mortality (P = .03). In all 14 patients alive at 1-year follow-up, ascites was controlled successfully. CONCLUSION: TIPS creation is often useful in treatment of severe ascites not controlled with medical therapy. In patients with advanced liver and renal failure, TIPS creation is not associated with a definite benefit and may hasten death.

Sonographic findings in bone marrow transplant patients with symptomatic hepatic venoocclusive disease.

Sonographic findings were retrospectively compared between 19 patients with hepatic venoocclusive disease and 23 patients with other common causes of symptomatic liver dysfunction after bone marrow transplantation (14 grafts versus host disease and nine hepatitis). Doppler sonographic examination was available in all patients with venoocclusive disease, in nine of the patients with graft versus host disease, and in three of the patients with hepatitis. The hepatic artery resistive index and the overall flow direction, peak forward and retrograde velocities, and time-averaged mean velocities in the hepatic veins and main portal vein were compared. The portal vein waveform was arbitrarily considered abnormal in the presence of any of the following: highly pulsatile waveform, very low mean velocity, biphasic flow, or flow reversal. Ascites was the most predictive gray scale sonographic finding for venoocclusive disease. Doppler sonographic findings of potential value in the diagnosis of hepatic venoocclusive disease include an abnormal portal vein waveform, resistive index of greater than 0.75, and marked thickening and edema of the gallbladder wall. However, the study is limited by its retrospective nature and reliance primarily on clinical criteria for the diagnosis of venoocclusive disease. Therefore, our findings will need to be verified in a large prospective study.

Correlation of the arterial resistive index in pancreas transplants of patients with transplant rejection.

OBJECTIVE: This study was undertaken to determine whether arterial resistive indexes (RIs) in pancreas transplants correlate with biopsy-proven transplant rejection. MATERIALS AND METHODS: We retrospectively reviewed arterial RIs in pancreas transplants for all patients who underwent Doppler sonography within 1 week before transcystoscopic or percutaneous biopsy of pancreas transplants. RIs were correlated with type and degree of rejection in the 20 transplants for which biopsies provided sufficient tissue for diagnosis. Three patients were subsequently eliminated from the study because of significant intervening therapy between sonography and biopsy. RESULTS: The nine transplants with no evidence of rejection had a mean arterial RI of 0.64 (range, 0.49-0.80). The six transplants with acute mild or moderate rejection had a mean RI of 0.67 (range, 0.56-0.73). The two transplants with acute severe rejection had a mean RI of 0.85 (range, 0.80-0.90). We found no statistically significant difference between arterial RIs in pancreas transplants of patients with acute mild or acute moderate rejection and those with no evidence of rejection. CONCLUSION: Arterial RIs of pancreas transplants do not differentiate between acute mild or acute moderate rejection and absence of rejection. The higher mean value of arterial RIs in pancreas transplants with acute severe rejection suggests that elevated arterial RIs are sensitive, but not specific, for revealing acute severe rejection of pancreas transplants. However, our study data are limited, and a larger sample size is necessary to draw statistically significant conclusions.

Ruptured or intact: what can linear echoes within silicone breast implants tell us?

OBJECTIVE: During sonographic evaluation of silicone breast implants for possible rupture, we have frequently encountered several patterns of linear echoes within the implants. To our knowledge, the significance of this finding has not been established in the literature. The purpose of this study was to determine whether internal echoes are significant in predicting implant rupture. SUBJECTS AND METHODS: Thirty-three patients with 64 silicone implants were prospectively entered into a study that included gray-scale sonography of the implants and subsequent surgical removal. Echo patterns within the implants were retrospectively evaluated on hard-copy films and compared with the integrity of the implant at surgery. RESULTS: Three categories of internal echo patterns were identified: "thick linear echoes." "thin linear echoes," and "commas." One or more of these echo patterns were seen in 57 (89%) of the 64 implants. Thick linear echoes were seen in 23 (36%) of the 64 implants, thin linear echoes were seen in 33 (52%) of the 64 implants, and commas were seen in 47 (73%) of the 64 implants. All echo patterns were seen in intact and ruptured implants with nearly equal frequency. We found no statistical significance for any echo pattern in predicting whether an implant was ruptured or intact. Of the 64 implants, four were entirely free of internal echoes. All four implants were intact. CONCLUSION: A variety of linear echoes can be seen in most silicone breast implants on gray-scale sonography. The presence or absence of linear echoes is not useful in predicting implant rupture. Complete absence of internal echoes, while highly predictive of an intact implant, is infrequently seen.

Masses simulating gynecologic diseases at CT and MR imaging.

The majority of pelvic masses in women arise from the reproductive tract. However, diseases of gastrointestinal origin (ruptured appendix, diverticular abscess, perforated rectosigmoid carcinoma), neurogenic origin (ganglioneuromas), primary extraperitoneal origin (presacral teratoma, soft-tissue sarcoma), and other miscellaneous disorders also occur in the pelvis and can be mistaken for gynecologic disease. Although determining the site of origin of a pelvic disease process can be difficult, several imaging signs can help differentiate an intra- from an extraperitoneal mass. These signs include displacement of the pelvic ureter, effacement or encasement of external iliac vessels, effacement of pelvic sidewall musculature, and displacement of the rectum. Depending on its exact location, an extraperitoneal mass can displace the pelvic ureter medially or anteriorly (compared with the lateral or posterolateral displacement caused by an ovarian mass), encase and obliterate the external iliac vessels, efface and compress the external iliac vein, abut and eventually efface the obturator internus muscle, or displace the rectum anteriorly or anterolaterally. Familiarity with these disease processes and the above imaging signs will facilitate accurate diagnosis and triage for treatment.

Evaluation of lower extremity bypass grafts with use of color duplex sonography.

This article reviews the wide variety of graft procedures currently used to bypass lower extremity atherosclerotic disease and the means used to evaluate the grafts, which can be biologic, synthetic, or a combination of both. Graft failure rate can be as high as 10% within the first 10-14 days after placement, leveling off to approximately 2%-4% per year thereafter. Many of the early complications associated with graft placement can be attributed to technical errors in bypass construction. Although angiography remains the standard of reference for the evaluation of these grafts, duplex ultrasound is increasingly being utilized to document patency and detect suspected complications such as intimal flap, perigraft collection, arteriovenous fistula, pseudoaneurysm, and stenosis or occlusion. Sonography is able to clearly depict the echogenic walls of synthetic grafts and demonstrate whether blood flow wave-forms and blood flow velocity in both synthetic and biologic grafts are normal, thus enabling a more accurate diagnosis of suspected complications to be made. Familiarity with the normal sonographic appearance of these grafts, their anastomoses, potential complications, and the pitfalls in making a diagnosis is essential if an accurate diagnosis is to be made.

Color Doppler sonography of the thoracic inlet veins.

Color duplex sonography of the thoracic inlet veins produces a spectrum of normal and abnormal findings. These vessels include the internal jugular, innominate, subclavian, and axillary veins. Although venography is the traditional means of imaging these veins, ultrasound lends itself to assessment of these vessels by providing anatomic and hemodynamic information. Advances in gray-scale resolution and color Doppler technology permit direct visualization of thrombus, stenosis, collateral vessels, catheters, and stents, as well as sensitive spectral waveform analysis. Abnormal findings in the thoracic inlet veins include locally elevated velocities at stenoses with low velocities peripherally. Thrombus, extrinsic compression, and collateral vessels may also produce abnormal findings. Common interpretive pitfalls are caused by transducer pressure, deep inspiration, slow flow, collateral veins, large-bore catheters, and hemodialysis fistulas. A thorough knowledge of the regional anatomy, normal and abnormal waveforms, and commonly encountered pitfalls will optimize the accuracy of color duplex sonography of the thoracic inlet veins.

Duplex sonography after transjugular intrahepatic portosystemic shunts (TIPS): normal hemodynamic findings and efficacy in predicting shunt patency and stenosis.

OBJECTIVE: Portal hemodynamics are altered by placement of a transjugular intrahepatic portosystemic shunt (TIPS). Normal duplex sonographic findings after TIPS placement and hemodynamic alterations indicating shunt failure have not yet been well described. The purposes of this study were to determine normal hemodynamic changes on duplex sonography after TIPS placement and to assess the efficacy of duplex sonography in detecting shunt dysfunction. SUBJECTS AND METHODS: Forty patients underwent TIPS placement and were entered into a study that included routine sonographic evaluation and portal venography at regular intervals. Portal venography was also performed if shunt velocities on duplex sonography changed from the baseline, which raised the question of shunt stenosis or occlusion. The pre-TIPS duplex sonographic study included determination of patency, velocity, and flow direction in the main, right, and left portal veins and in the hepatic artery. Follow-up sonography included the pre-TIPS examination in addition to velocity determinations in three segments of the shunt. Correlation was made between 82 concurrent sonographic and portal venographic studies. RESULTS: High-velocity blood flow (mean peak velocity, 135-200 cm/sec) was consistently seen within patent, well-functioning shunts. Hepatic artery peak systolic velocities increased from 79 cm/sec before TIPS placement to 131 cm/sec after TIPS placement (p < .001). Main portal vein velocities increased from 21.8 cm/sec before TIPS placement to 41.5 cm/sec after TIPS placement (p < .001). When compared with portal venography, duplex sonography was 98% sensitive and 100% specific in predicting the presence of blood flow within the stent. Sonography was highly sensitive and specific for detecting stent stenosis. Final sonographic criteria for shunt stenosis in angiographically documented cases were low-velocity shunt flow (< or = 60 cm/sec) in the entire stent, or low-velocity shunt flow with an associated focal velocity elevation. CONCLUSION: Consistent changes in portal venous and hepatic arterial hemodynamics are normally seen on duplex sonography after placement of a TIPS. Duplex sonography accurately predicts shunt patency and dysfunction when compared with portal venography. Duplex sonography is an effective, noninvasive method of evaluating shunt function and should be considered for use as the primary imaging technique in routine follow-up after TIPS placement.

Laparoscopic drainage of lymphoceles after kidney transplantation: indications and limitations.

BACKGROUND: Symptomatic lymphoceles are not uncommon after kidney transplantations. Surgical marsupialization with internal drainage is the treatment of choice. However, laparoscopic drainage is reportedly as effective, with only minimal trauma. METHODS: We attempted 14 laparoscopic lymphocele drainages during a 3-year period and studied the indications and limitations, using intraoperative ultrasonography in all cases. RESULTS: Laparoscopic drainage was successful in only 9 (64%) of 14 patients. A conversion to open laparotomy was necessary in five patients; their lymphoceles were lateral and either posterior or inferior to the kidney. Two patients with initially successful laparoscopic drainage required conversion to open laparotomy 21 and 83 days later; their lymphoceles were inferior to the kidney. Laparoscopic drainage shortened the median hospital stay by 4 days versus open surgical drainage and by 7 days versus conversion. Hospital costs for laparoscopic drainage averaged $7400 less versus open drainage and $10,300 less versus conversion. CONCLUSIONS: In patients with symptomatic lymphoceles medial and either superior or anterior to the kidney, laparoscopic drainage under intraoperative ultrasonographic guidance is easy, safe, and effective. It decreases hospitalization, convalescence, and costs. In patients with symptomatic lymphoceles lateral and either posterior or inferior to the kidney, laparoscopic drainage may fail because of anatomic inaccessibility and technical impracticability.

Color Doppler sonography of transjugular intrahepatic portosystemic shunts (TIPS).

Transjugular intrahepatic portosystemic shunts (TIPS) have largely replaced surgically created shunts in the treatment of life-threatening sequelae of portal venous hypertension [1-5]. Conventional duplex and color Doppler sonography are proving to be useful tools in the assessment of the stents and their associated hemodynamic changes [2-5]. A thorough Doppler survey before and immediately after TIPS placement provides a baseline for evaluation of shunt function and procedure-related complications. Routine follow-up studies at regular intervals after the procedure provide noninvasive assessment of shunt patency and late complications. This pictorial essay illustrates the anatomic and hemodynamic abnormalities present with portal hypertension before TIPS and discusses the expected duplex and color Doppler findings after TIPS. The sonographic characteristics of immediate and delayed complications, as well as potential diagnostic pitfalls, are discussed.

Diagnosis of breast implant rupture: imaging findings and relative efficacies of imaging techniques.

OBJECTIVE: The purpose of this study was to compare the efficacies of mammography, sonography, CT, and MR imaging in the detection of breast implant rupture and to analyze the imaging findings. SUBJECTS AND METHODS: Thirty-two women with 63 silicone breast implants participated in the study. All but one had signs and symptoms suggestive of rupture, and all had requested that their implants be removed before they were enrolled in this imaging study. All patients had film-screen mammography, sonography, CT, and MR imaging. Twenty-two ruptures were found at surgery; 21 were intracapsular and one was extracapsular. The relative efficacies of the imaging studies were determined, and the imaging findings were compared with the surgical results. RESULTS: Of the 32 women with 63 implants, mammographic sensitivity for detecting implant rupture was only 23% but the specificity was 98%. Sonography had a higher sensitivity (59%), but its specificity was significantly lower (79%). CT had a sensitivity of 82% and a specificity of 88%. MR was the only imaging technique that consistently provided evidence that enabled the evaluation of intracapsular and extracapsular ruptures. The sensitivity and specificity of MR imaging were 95% and 93%, respectively. CONCLUSION: Our results show that MR imaging is more sensitive and specific for the detection of breast implant rupture than is mammography, CT, or sonography.

Development of stenoses in transjugular intrahepatic portosystemic shunts.

PURPOSE: To evaluate the frequency and significance of stenoses or occlusions developing within transjugular intrahepatic portosystemic shunts (TIPS) and identify predictive factors. MATERIALS AND METHODS: Medical records of 52 patients who underwent TIPS placement between September 1991 and October 1993 were reviewed. Various shunt parameters were correlated with the development of shunt abnormalities. Findings at follow-up portography and frequency of variceal bleeding and paracentesis were also noted. RESULTS: Twenty-four patients were followed up for at least 6 months. In eight patients, stenoses developed within 6 months; one shunt occluded. No clear correlations were found between shunt parameters and development of shunt abnormalities. Two of four patients with recurrent variceal bleeding had associated shunt abnormalities. The frequency of stenosis of TIPS was high. CONCLUSION: Early detection and prompt revision of stenotic shunts may decrease the frequency of recurrent variceal bleeding and ascites.

Duplex and color Doppler sonography of complications after percutaneous interventional vascular procedures.

Duplex and color Doppler sonography have proved to be excellent noninvasive modalities for evaluating complications of percutaneous interventional vascular procedures. Complications including hematoma, pseudoaneurysm, arteriovenous fistula, thrombosis, stenosis, and vessel occlusion are routinely diagnosed with Doppler sonography. Hematomas exhibit variable echogenicity and internal complexity but never demonstrate internal blood flow. A pseudoaneurysm is a contained extravasation of blood that, unlike a hematoma, maintains a patent vascular connection with the injured vessel. Puncture-related arteriovenous fistulas are false vascular channels between an adjacent artery and vein that demonstrate low-resistance arterial signal, high-velocity venous outflow, and variable flow patterns within themselves. Narrowing in a stent demonstrates high-velocity turbulent flow with conventional Doppler and color aliasing with color Doppler techniques. Thrombus can be seen directly as a mural-based or luminal defect; however, it is often alterations in color flow dynamics, waveform characteristics, and flow velocities that permit conclusive diagnosis. Early experience in evaluation of stent stenosis in patients with transjugular intrahepatic portosystemic shunts suggests that low-velocity shunt flow indicates stenosis, likely related to the presence of low-resistance collateral pathways. Familiarity with both the interventional procedures and their possible complications facilitates prompt diagnosis and treatment.

CT anatomy of the female pelvis: a second look.

Computed tomography (CT) remains a valuable technique in the assessment of the female pelvis. The CT appearance of the normal ligamentous, vascular, and visceral anatomy of the female pelvis can be confusing. Newer high-resolution CT scanners combined with mechanical intravenous contrast medium injectors and thinner sections have substantially improved the imaging of female genital tract anatomy. In addition to the cardinal, uterosacral, and round ligaments, the ovaries and their ligamentous attachments, as well as the blood supply to the female internal organs, can now be visualized. Inferior-to-superior image acquisition following bolus administration of intravenous contrast material with an angiographic injector facilitates precise identification of the uterine artery and its relationship to the pelvic ureter and the vascular plexus supplying the vagina, ovaries, and uterine body. Ideally, familiarity with variations in the CT appearance of normal female pelvic anatomy will enable more accurate evaluation of pelvic abnormalities.

Early sonographic evaluation of the transjugular intrahepatic portosystemic shunt (TIPS).

The purpose of this study was to evaluate duplex and color Doppler findings in patients before and within 24 h after transjugular intrahepatic portosystemic shunts (TIPS). Conventional duplex and color Doppler were used in the assessment of 19 patients who underwent TIPS as part of a prospective protocol. Patients were examined within 24 h before and after the procedure. Before TIPS, patency, flow direction, and peak flow velocity in the main portal vein and hepatic artery were studied, as well as patency and flow direction in hepatic veins, splenic vein, and inferior vena cava (IVC). Immediately after the procedure, sonographic identification of stent position, shunt patency, and flow dynamics were evaluated and patency and flow direction of hepatic veins, splenic vein, and IVC were determined. The portogram performed at the end of the procedure was compared with the 24-h sonographic studies after TIPS to determine sonographic/angiographic correlation. No intraparenchymal abnormalities or perihepatic fluid collections were detected after the procedure. The metallic stent was clearly seen in all patients. Mean peak shunt flow velocities were 139 +/- 50 cm/sec within 24 h after TIPS. Absence of flow through the shunt was correctly identified in one case and confirmed angiographically. Mean peak flow velocity in the portal vein before TIPS was 22 +/- 13.6 cm/sec and increased to 43.6 +/- 9.1 cm/sec after TIPS (p < 0.05). The hepatic artery peak systolic velocity increased from 77 +/- 51 cm/sec before TIPS to 119 +/- 53 cm/sec after the procedure (p = 0.029).(ABSTRACT TRUNCATED AT 250 WORDS)