Venous Compromise Research Articles

High Intracranial Pressure, Brain Herniation and Death in Cerebral Venous Thrombosis

To the Editor: Sir, the study by Canhao and colleagues made the important point that the most frequent cause of death in patients with cerebral venous thrombosis (CVT) is transtentorial herniation and that these patients may potentially have benefited from decompressive hemicraniectomy.1 We would like to corroborate this argument by providing evidence for a rise in intracranial pressure (ICP) preceding brain herniation and death in a patient with CVT. A 29-year-old pregnant woman who presented with confusion and vomiting was admitted to a district general hospital. A right-sided weakness developed within 2 days. A CT brain scan showed a left temporal hemorrhage without mass effect. Her Glasgow Coma Scale score dropped to 8/15; she was intubated and transferred to the neurocritical care …

Radial Forearm Osteocutaneous Free Flap in Maxillofacial and Oromandibular Reconstructions

The radial forearm osteocutaneous free flap is an excellent reconstructive modality for oromandibular and maxillofacial reconstruction in certain well-defined circumstances. The initial concern over donor site morbidity and the ability of the bone to reconstruct mandibular defects have led to only a few published series. Retrospective study of the experience of two tertiary medical centers with radial forearm osteocutaneous free flap. Retrospectively, 52 patients were studied who underwent radial forearm osteocutaneous free flap reconstruction for cancer (49 cases) and trauma (3 cases). Bone length and skin paddle harvested, general morbidity (hematoma, wound infection, and dehiscence), recipient site morbidity (nonunion of neomandible, flap failure, and bone or plate exposure), and donor site morbidity (radius bone fracture, plate exposure, and skin graft failure) were reviewed. The average skin paddle size was 55.1 cm (range, 15-112 cm). The average radius bone harvest length was 6.3 cm (range, 2.5-11 cm). Donor site complications included tendon exposure (3 cases), radius bone fracture (1 case), and exposure of the plate (0). Recipient site complications included nonunion of the mandible (4), exposed mandible (1), exposed mandibular plates (2), exposed maxillary plates or bone (0), venous compromise (1), and flap failure (1). Two patients had perioperative deaths. Radial forearm osteocutaneous free flap is a valuable and viable option for oromandibular and maxillofacial reconstruction.

Efficacy of Venous Supercharging of the Deep Inferior Epigastric Perforator Flap in a Rat Model

An insidious risk with the use of muscle perforator flaps is the possibility of venous outflow compromise. Congestion in deep inferior epigastric perforator (DIEP) flaps in particular is not infrequent. On an empiric basis, their salvage has been accomplished by augmenting venous drainage through alternative outflow tracts. The validity of this clinical maneuver can now best be tested in a rat DIEP flap model. The rat DIEP flap is a modification of the rat ventral abdomen flap. Flap perfusion can be based on a single rectus abdominis musculocutaneous perforator. No muscle is included with the flap. Three groups of five male Sprague-Dawley rats each were used. The conventional DIEP flap group had only a solitary perforator artery and venae comitantes and served as the control. The contralateral superficial inferior epigastric vein was included with the flap in the other two groups as a distinctly separate venous outflow tract. The latter two groups differed in that the perforator venae comitantes were either retained or deleted. Mean flap survival in the control DIEP flap group was 80.8 +/- 16.3 percent. Retention of the contralateral superficial inferior epigastric vein resulted in a statistically significant enhancement in flap viability (p < 0.027) whether the perforator venae comitantes were left intact (99.8 +/- 0.4 percent) or had been intentionally ablated (99.6 +/- 0.5 percent). Venous supercharging of the rat DIEP flap ensures greater flap survival. As a corollary, this supports the efficacy of prior anecdotal experiences in which an alternative venous outflow tract, preferably from the superficial system, had been used to overcome venous congestion. It is advisable for any muscle perforator flap to always try to retain a second outflow source to allow the potential for venous supercharging, if later indicated.

Salvage of partial facial soft tissue avulsions with medicinal leeches

Medicinal leeches have been demonstrated to be extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. To demonstrate the utility of medicinal leeches in the salvage of venous outflow-compromised traumatic soft tissue avulsions in key facial structures. A retrospective review of 4 cases involving the external ear, nose, lip, and scalp in which apparent venous outflow compromise was present. Medicinal leeches were applied acutely in each of these 4 cases, salvaging each of the partially avulsed soft tissue segments. Complete or near complete salvage of each soft tissue segment after using medicinal leeches. Although it is unusual for a partial soft tissue avulsion of the face to require medicinal leech therapy, situations may occur in which there is adequate arterial inflow but inadequate venous outflow. In such cases, medicinal leeches may play a very important role in salvaging the soft tissue segment. This is particularly important in vital structures such as the ear, nose, lip, and eyelid in which acute or secondary reconstruction is complex. C.

A NOVEL METHOD FOR ANALYSIS OF POSTOPERATIVE LIVER REGENERATION IN THE ADULT LIVE LIVER DONOR

O447 Aims: Proprietary software has been recently developed that dramatically improves preoperative and postoperative evaluation of live donor liver anatomy and regeneration. Better understanding of the determinants and dynamics of liver regeneration after right lobe live donor hepatectomy may lead to optimization of surgical technique and improve the ability to predict expected regeneration in an individual patient. Methods: Dynamic spiral CT was performed preoperatively and postoperatively in right lobe liver donors at 1week, 4 weeks, 3, 6 and 12 months after donation. Digital image data analysis was performed on 10 donors using proprietary software (Hepavision2, MeVis, Bremen, Germany). Semi-automatic quantification of total liver volume, true anatomic portal venous territory volume as well as portal venous branch length in regenerating liver segments was performed. Results: We derived a power law behaviour for the volume growth of true vascular territories in the remnant liver lobe. This means that the increase in portal venous branch length scales with the third root of the increase of territorial volume over time. An example of 3-dimentional renderings of remnant volumes and portal vein length at different time points in a donor are shown below.FigureLegend:Left image shows donor liver split into Graft (blue) and Remnant (red) along dotted line, numbers denote borders of regenerating remnant at specific time points (#1: 1week[536cc], #2: 4weeks[484cc], #3: 6months[564cc], #4: 12months[587cc]. Right image shows corresponding superimposed growing portal veins in regenerating remnant liver, each color denotes different point in time. Conclusions: From a macroscopic viewpoint, donor liver regeneration is characterized by scaled growth of existing vessels and territorial volumes. This means that liver regeneration is a “scaling phenomenon” that can be predicted mathematically. Territorial plasticity of liver regeneration was found to be dependent on the absence of postoperative venous compromise of the remnant lobe. Additional studies are needed to further elucidate the determinants of liver regeneration.

Venous drainage of the platysma myocutaneous flap

Objectives The platysma myocutaneous flap offers a regional reconstruction option for relatively small soft tissue defects in the head and neck area. However, epidermolysis of its skin paddle with resultant fibrosis and tongue tethering has been documented. This has been attributed to arterial and/or venous vascular compromise. We investigated the venous drainage patterns of this flap in a cadaveric study. Study design and setting We made selective Microfil dye injections into the external and internal jugular veins of 5 cadavers. A wide cervical flap was then raised, and anatomic dissection of the superficial and deep venous systems was performed to identify the dominant draining veins of the platysma flap. Results Universally, small communicating veins from the internal jugular venous system were noted to drain the platysma flap anteriorly. The external jugular vein was noted to drain the flap posteriorly. Conclusions Although it is difficult to preserve the anterior communicating veins with 180° flap rotation, the results of this study suggest a possible benefit of external jugular vein harvest in continuity with the platysma flap. Further clinical studies are needed to assess whether flap venous congestion, epidermolysis, and resultant fibrosis can be minimized with this technique.

Surgical treatment of acl-pcl-medial side-lateral-side injuries of the knee

The multiple-ligament-injured knee is a complex problem in orthopaedic surgery. Most dislocated knees involve tears of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and at least one collateral ligament complex. Careful assessment of the extremity vascular status is essential because of the possibility of arterial and/or venous compromise. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and to formulate a treatment plan. Arthroscopically assisted combined ACL/PCL reconstruction is a reproducible procedure. Knee stability is improved postoperatively when evaluated by using knee-ligament rating scales, arthrometer testing, and stress radiographic analysis. Acute medial collateral ligament tears when combined with ACL/PCL tears may, in certain cases, be treated with bracing. Posterolateral corner injuries combined with ACL/PCL tears are best treated with primary repair, as indicated, combined with reconstruction by using a post of strong autograft (split biceps tendon, biceps tendon, semitendinosus) or allograft (Achilles tendon, bone—patellar tendon—bone) tissue. Surgical timing depends on the ligaments injured, the vascular status of the extremity, reduction stability, and the overall health of the patient. We prefer the use of allograft tissue for reconstruction in these cases because of the strength of these large grafts and the absence of donor-site morbidity.

Endovascular treatment of malignant superior vena cava syndrome: is bilateral wallstent placement superior to unilateral placement?

To report our experience with unilateral versus bilateral stent placement in the treatment of malignant superior vena cava syndrome (SVCS). The records and films of 84 consecutive patients (69 men; mean age 64+/-10 years, range 39-79) referred for stent placement in malignant SVCS were reviewed for venous compromise, technical and clinical success, complications, and reocclusions. Wallstents were placed covering the SVC and both (bilateral technique) brachiocephalic veins (BCV) preferentially; unilateral stenting of only one BCV in addition to the SVC was performed based on operator preference or inability to access both sides. Technical success was defined as the ability to stent the SVC and at least one BCV; clinical success was the elimination of SVCS symptoms. Technical success was achieved in 83 (99%) patients, using the unilateral technique in 22 and bilateral stenting in 61 patients. The groups did not differ with regard to age, sex, underlying diseases, or location and extent of venous compromise. Immediate clinical success was achieved in 20 (91%) of 22 patients in the unilateral group and 55 (90%) of 61 patients in the bilateral group. Two patients suffered late occlusion in the unilateral group, while in the bilateral group, 8 patients had early occlusion and 9 had late occlusion. Thus, the total occlusion rate was significantly (p<0.05) lower in the unilateral group. There was 1 other complication (pericardial tamponade) in the bilateral group, for a 28% total complication rate, which was significantly higher (p=0.039) than the 9% in the unilateral group. The 1, 3, 6, and 12-month primary stent patency rates were 90%, 81%, 76%, and 69%, respectively. Patency tended to last longer in the unilateral group, but the difference was not significant (p=0.11). Although bilateral Wallstent placement achieved equal technical and clinical success, it tended to confer shorter-lived patency and caused more complications.

Effects of PEEP on Residual Vascularization in Oesophageal Substitution Gastroplasty by Surface Oximetry-Capnometry and Photoplethysmography

Objective: To evaluate the effects of positive end-expiratory pressure (PEEP) on residual vascularization in gastric tubes for oesophageal replacement. Design: Experimental open study. Materials: Eleven mongrel dogs. Methods: Intestinal parietal blood flow was evaluated by photoplethysmography (PPG) and measurement of surface oxygen (PsO₂) and carbon dioxide (PsCO₂) tensions under basal conditions. After Akiyama’s tubular gastroplasty, three levels of PEEP were administered. At each level, fluids were infused to counter the drop in cardiac output. PPG, surface gas tensions, arterial pressure, cardiac output and arterial blood gas tensions were monitored. Control sections of the bowel were also monitored by PPG. Results: Cardiac output dropped for each level of PEEP and returned to basal levels on volume restabilization and on removal of PEEP. Central venous pressure and pulmonary arterial and capillary pressures increased for each level of PEEP and only returned to basal levels on removal of PEEP. PsO₂ values dropped for each level of PEEP and returned to basal levels on volume restabilization and on removal of PEEP. PsCO₂ levels rose, and PPG wave amplitude dropped, for each level of PEEP; these two variables only returned to basal levels on removal of PEEP. PPG values for the control sections reflected those of the anastomotic area. Conclusions: PEEP affects surface oxygen values at the level of the gastroplasty by means of its effect on cardiac output. PEEP also creates a venous return compromise and PPG wave amplitude and surface carbon dioxide values are related to this compromise. All three variables could be significant in anastomotic wound healing.

Pyelocalyceal diverticulum: an unusual cause of acute renal colic

The differential diagnosis of acute flank pain includes kidney stones, urinary tract infection, dissecting abdominal aortic aneurysm (AAA), arterial or venous compromise of the kidney, renal abscess, renal carcinoma, and papillary necrosis. This is a report of an unusual cause of renal colic: pyelocalyceal diverticulum. Stasis of urine within a diverticulum promotes both calculus formation and urinary tract infection, either of which can lead to colic. Several radiographic findings may suggest a calyceal diverticulum, including, on plain X-ray, a very peripheral or mobile renal calculus, or on intravenous pyelogram, an early filling-defect and delayed or retained filing of a circular or ovoid mass.

Combined Anterior/Posterior Cruciate Ligament/Medial/Lateral Side Injuries of the Knee

The multiligament-injured knee is a complex problem in orthopedic surgery. These injuries may or may not present as acute knee dislocations, and careful assessment of the vascular status of the extremity is essential because of the possibility of arterial or venous compromise. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and formulate a treatment plan. Arthroscopically assisted combined anterior/posterior cruciate ligament reconstruction is a reproducible procedure. Knee stability is improved postoperatively when evaluated with knee ligament rating scales, arthrometer testing, and stress radiographic analysis. Surgical timing depends on the injured ligaments, vascular status of the extremity, reduction stability, and the overall health of the patient. The use of allograft tissue is preferred because of the strength of these large grafts and the absence of donor site morbidity.

Alterations in hepatic perfusion resulting from splanchnic venous luminal compromise caused by pancreatic carcinoma.

We determined whether alterations in hepatic enhancement exist on dual phase helical CT of the liver in patients with splanchnic venous luminal compromise resulting from pancreatic adenocarcinoma. We examined the extent of hepatic enhancement on dual phase helical CT in 22 patients with pancreatic adenocarcinoma. Eleven patients had splanchnic venous luminal narrowing (flattening along at least 120 degrees of the circumference) of the superior mesenteric vein with (n = 3) or without (n = 8) portal vein involvement caused by tumor. In the remaining patients, splanchnic vasculature appeared normal. An additional 16 patients without pancreatic or hepatic abnormality who underwent dual phase helical CT served as control subjects. We compared the extent of arterial phase and portal venous phase enhancement among the three groups. The group of patients with splanchnic venous luminal compromise had significantly higher hepatic enhancement during the arterial phase (p < 0.01) and lower enhancement during the portal venous phase (p < 0.05) compared with the other two groups of patients. No significant difference in hepatic enhancement during either phase was noted between the control subjects and the patients with normal vasculature. Because hepatic enhancement correlates with perfusion, splanchnic venous luminal compromise resulting from pancreatic adenocarcinoma likely causes decreased portal venous flow and compensatory increased hepatic arterial flow. This finding supports other evidence of a homeostatic mechanism that maintains hepatic perfusion.

Osteochondroma: MR imaging of tumor-related complications.

Osteochondromas can be complicated by mechanical irritation, compression or injury of adjacent structures, fracture, malignant transformation, and postoperative recurrence. Magnetic resonance imaging represents the most valuable imaging modality in symptomatic cases, because it can demonstrate typical features of associated soft tissue pathology, which can be differentiated from malignant transformation. Reactive bursae formation presents as an overlying fluid collection with peripheral contrast enhancement. Dislocation, deformation, and signal alterations of adjacent soft tissue structures can be observed in different impingement syndromes caused by osteochondromas. Magnetic resonance imaging provides excellent demonstration of arterial and venous compromise and represents the method of choice in cases with compression of spinal cord, nerve roots, or peripheral nerves, depicting changes in size, position, and signal intensity of the affected neural structures. Malignant transformation as the most worrisome complication occurs in approximately 1% of solitary and 5-25% of multiple osteochondromas. Magnetic resonance imaging is the most accurate method in measuring cartilage cap thickness, which represents an important criterion for differentiation of osteochondromas and exostotic (low-grade) chondrosarcomas. Cartilage cap thickness exceeding 2 cm in adults and 3 cm in children should raise the suspicion for malignant transformation. Finally, MR imaging can detect postoperative recurrence by depiction of a recurrent mass presenting typical morphological features of a cartilage-forming lesion.

Cellulitis syndromes: an update

Cellulitis is a commonly seen clinical syndrome that is most often associated with β-haemolytic streptococci and Staphylococcus aureus. Several medical conditions and a variety of procedures can predispose to the development of cellulitis by a common mechanism: venous and lymphatic compromise. The precise pathophysiologic and immunologic details involved in the predisposition to cellulitis remain poorly understood. Therapy is directed at resolution of acute infection and prevention of recurrent episodes of cellulitis.

Monitoring free flaps using the laser Doppler flowmeter: five-year experience.

Over a 5-year period, 232 microvascular composite-tissue transfers to the head and neck, trunk, and extremities were monitored using the laser Doppler flowmeter. Thirteen free flaps (5.6 percent) developed vascular complications, all within 4 days after surgery. The laser Doppler flowmeter detected vascular compromise in all cases with no false positives or negatives. Failure to monitor the flap according to protocol by nursing staff occurred in one patient, which led to a delay in detection of venous compromise and subsequent flap loss. The salvage rate was 69.2 percent, leading to an overall flap viability of 98.3 percent. Our series of free-flap monitoring using the laser Doppler flowmeter is the largest reported to date. Review of the English literature shows consistent support by numerous clinical series for the use of the laser Doppler as a valuable postoperative monitor after free-flap transfers.

Management of the dislocated/multipleligament injured knee

The multiple ligament injured knee is a complex problem in orthopaedic surgery. Most dislocated knees involve tears of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and at least one collateral ligament complex. Careful assessment of the vascular status of the extremity is essential because of the possibility of arterial and/or venous compromise. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and to formulate a treatment plan. Arthroscopically assisted combined ACL/PCL reconstruction is a reproducible procedure. Knee stability is improved postoperatively when evaluated using knee ligament rating scales, arthrometer testing, and stress radiographic analysis. Acute medial cruciate ligament tears, when combined with ACL/PCL tears, may, in certain cases, be treated with bracing. Posterolateral corner injuries combined with ACL/PCL tears are best treated with primary repair as indicated combined with reconstruction using a post of strong autograft (split biceps tendon, biceps tendon, semitendinosus) or allograft (Achilles tendon, bone patellar tendon bone) tissue. Surgical timing depends on the ligaments injured, the vascular status of the extremity, reduction stability, and the overall health of the patient. We prefer the use of allograft tissue for reconstruction in these cases because of the strength of these large grafts and the absence of donor site morbidity.

Management of combined anteriorcruciate ligament/posterior cruciate ligament/posterolateral complex injuries of the knee

The multiple ligament injured knee is a complex problem in orthopedic surgery. These injuries may present as acuteknee dislocations, and careful assessment of the extremity vascular status is essential because of the possibility of arterial and/or venous compromise. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and formulate a treatment plan. Arthroscopically assisted combined anterior cruciate ligament/ posterior cruciate ligament (ACL/PCL) reconstruction is a reproducible procedure. Knee stability is improved postoperatively when evaluated with knee ligament rating scales, arthrometer testing, and stress radiographic analysis. Posterolateral complex (PLC) injuries combined with ACL/PCL tears are best treated with primary repair as indicated combined with PCL reconstruction using a post of strong autograft (split biceps tendon, biceps tendon, semitendinosus), or allograft (Achilles tendon, bone-patellar tendon-bone) tissue. Surgical timing depends on the injured ligaments, vascular status of the extremity, reduction stability, and overall patient health. The use of allograft tissue is preferred because of the strength of these large grafts and the absence of donor site morbidity.

An Alternative Approach: Antegrade Catheter-directed Thrombolysis in a Case of Phlegmasia Cerulea Dolens

Phlegmasia cerulea dolens is an uncommon sequela of severe deep venous thrombosis of the lower extremities. Characterized by massive edema, arterial and venous compromise, and threats to limb and life, this clinical entity is a clear indication for thrombolytic therapy. We report an innovative approach to conventional thrombolysis via a lesser saphenous vein cut-down. This simple technique is a safe, reliable alternative to present methods of achieving deep venous access. Hence, it should be considered as an addition to the treatment armamentarium for massive deep venous thrombosis of the lower extremity.

Treatment of infected tunneled venous access hemodialysis catheters with guidewire exchange

Cuffed venous access catheters have become commonplace for hemodialysis access. The major complications of these catheters are catheter thrombosis, catheter fibrin sheathing and infection. When catheter associated bacteremia occurs treatment with antimicrobial therapy alone has been unsuccessful in providing acceptable cure rates. Failed antimicrobial therapy exposes the patient to the risks of prolonged bacteremia, while the alternative, catheter replacement at a new site can lead to central venous stenosis and compromise future long-term upper extremity access. Catheter guidewire exchange when the tunnel tract is clinically not infected theoretically allows the preservation of future access sites and yields a higher treatment success rate while avoiding temporary non-cuffed access placement. We report a series of 23 cases of hemodialysis patients with tunneled cuffed catheters and bacteremia related to the catheter who were treated with the exchange of a new catheter over a guidewire combined with three weeks of systemic antibiotics. Patients eligible for the study required no evidence of tunnel tract infection and defervescence within 48 hours of antimicrobial therapy. Technique failure was defined as repeat infection from any organism within 90 days of catheter exchange. Four patients (18%) redeveloped bacteremia within 90 days of the exchange. The bacteremias developed at 4, 19, 63 and at 74 days days after the exchange. Guidewire exchange in combination with intravenous antibiotics in cases of catheter related bacteremia has an acceptable rate of treatment success and is a viable treatment option in a carefully selected patient population.

Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction.

The incidence of internal jugular vein thrombosis (IJVT) following a modified neck dissection remains uncertain. The effect of, or consequences following, IJVT upon pedicled and free flap head and neck reconstructions remains unexplored. Twenty-nine preserved internal jugular veins in 24 patients undergoing modified neck dissection were available for prospective study. All patients required a pedicled or free flap reconstruction and received a modified, unilateral or bilateral cervical lymphadenectomy. The patency of all jugular veins was determined preoperatively and postoperatively using a combination of computed tomography (CT) scanning, high-resolution ultrasound, and color-flow Doppler (CFD). The IJVT rate was 14%. The presence of a pedicled myocutaneous flap and left-sided jugular dissections may represent risks to the postoperative patency of the internal jugular vein. Preoperative radiotherapy did not appear to impact negatively upon the thrombosis rate. Thrombosis of the internal jugular vein may result in significant morbidity for the postoperative oncologic patient. An internal jugular-dependent-free-tissue transfer may risk venous compromise of the flap, whereas the use of a pedicled flap may place the jugular at increased risk for thrombosis. Strategies for deep venous system microvascular recipient recruitment in the head and neck are discussed. Wherever possible, we employ two deep venous systems, the internal jugular, and subclavian (via the external jugular) for flap drainage.