Oncovascular Surgery; Surgery of the Vena Cava-Related Tumors
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One really wonders whether surgery is a branch of medicine or is it a branch of construction engineering
One really wonders whether surgery is a branch of medicine or is it a branch of construction engineering
The inferior vena cava, one of the most dreaded organs in abdominal surgery, is always blamed for killing subjects and more often is held the responsibility of the inoperability and irresectability of malignant disease.
Lying silently in the very depth of the abdominal cavity with many organs on its top, remaining patent despite its low pressure and unenforced wall.
The case for vena cava’s implication in irresectability of tumors is similar to the usual scenario of living with human beings, the more you take responsibilities and commitments on your shoulder, the more you will be involved in issues of different kinds. The more you do, the more you will be blamed. This is the case with the vena cava, an organ with a very major role and numerous responsibilities and commitments to other organs with which it is connected to with tributaries many of which are critical.
As surgeons we commonly respond to this condition by abandoning or at least inconsistently doing surgery for tumors around the cava. While in fact all what it takes to perform surgery on an organ with multiple commitments is to be patient enough in the preparatory phase of surgery to repeat multiply the same step should the organ have had a single commitment.
If one would invest time to free the vena cava from its commitments and tributaries, he would find a very cooperative organ that would stand to his side and the side of the patient I assure.
So here comes the question: can all the vena cava-related tumors be resected?
With the use of current surgical and anesthesia facilities, perhaps the answer will be yes.
32.2 Types and Different Views for Classifying Vena Cava-Related Tumors
Different ways to classify vena cava-related tumors
1. Anatomical, according to organ of origin:
Posterior segment rt.lobe liver
Caudate lobe liver
Soft tissue of retroperitoneum
Different types of carcinomas and sarcomas according to the organ
Some benign and low-grade tumors of retroperitoneal tissues and organs
1. Tumors adjacent to the cava or encasing without infiltration
2. Tumors infiltrating the full thickness of the wall
3. Tumors inside the caval lumen
First is anatomical, i.e., according to the organ of origin.
Second is pathological, i.e., according to the histopathology of the tumor.
Third is technical (see later).
When you add the anatomy to the pathology, you can get numerous possibilities and combinations of anatomies-pathologies complexes.
The surprise carried by this chapter is that it is not about listing the vena cava-related tumors and then running through them to describe different operations for different tumors. Not at all.
This article is about introducing, as the title described, the concept of vena cava-related tumors all in one and encompassed as a single entity. The chapter’s purpose is to describe the basic principles and the logic behind a single unified approach for what the author sees as a single entity from the technical standpoint unifying a variety of anatomies and pathologies when it comes to resection, an approach that enables getting to terms with the vena cava and may be with every retroperitoneal resection surgery.
Technically speaking, IVC-related tumors can be looked at as of three types:
Tumors adjacent to the cava without infiltration
Tumors infiltrating the caval wall
Tumors inside the cava
32.2.1 General strategy of resection (the 4 phases of the surgery)
The four main phases for resection of vena cava-related tumor
Look at the scans and define the circle of interest, i.e., field of surgery (see text for description)
Phase 1: Mobilization of organs from in front of the circle of interest
Phase 2: Control of “ins and outs” to and from the circle of interest defined and now cleared from superficial structures by virtue of phase one
Phase 3: Complete (lateral and posterior) mobilization of the tumor-cava complex
Phase 4: Three options
1. Subadventitial dissection of the cava
2. Resection of cava with the tumor and replacement as appropriate
3. Opening the cava to excise a tumor from within the lumen
There will be no surgery for any retroperitoneal structure (which is the case for the cava) without the more superficial organs regardless their name, size, and relevance being moved out of the way. This is basic and final. The problem is that sometimes the size of the tumor overshadows the organs and attracts the surgeons’ attention as soon as the abdomen is open, and therefore the surgeon goes straight to the visible and palpable part of the tumor disregarding the invisible part and disregarding the fact that he is only palpating the tumor through the full thickness of other organ, for instance, a thinned out mesentery of small bowl and colon. The anatomy will stay a fact; no matter how big the tumor is, this will never get the organs and their attachments to disappear. They might just be overshadowed or change the very usual position, but they will indeed remain in the abdomen.
The general configuration of organs in the abdomen is that we have two central structures which offer blood supply—namely, IVC and aorta—while the rest of the organs are on either sides of such central structures or on top of it. Whether on the sides or on top, they need to connect to the central structures by branches which will run in an axial plane for organs on the sides and in a sagittal plane for organs on top (superficial).
The organs in the abdomen lie in specific locations. Two categories of attachments keep them in position. First is their “ins and outs,” namely, blood vessels and ducts, if any. These are unnegotiable; there interruption entails either resection of the organ or the need for a restorative surgery in most of the occasions.
What is dispensable in almost all abdominal organs is the second category which is the ligamentous attachments which in fact are nothing but perfectly dispensable peritoneal folds.
One would be amazed how much mobility that the organs acquire as a consequence to the complete division of these almost bloodless and routinely accessible peritoneal reflections. A degree of mobility that makes the need to divide any of the first category attachments unnecessary in almost all surgeries of the abdomen. When these cuts are made as complete as they can get, every organ on the right-hand side can go to the extreme left and vice versa and sometimes can be even flipped cranially or caudally. In a sense the blood supply will act as a fulcrum with the organ at its distal end having a 3D mobility in different directions and hence exposing the central structures in the retroperitoneum.
The ability and the will for mobilizing whatever necessary of the abdominal organs is the key to accessing the vena cava.
Access solves almost all problems in surgery because otherwise one would do nothing but making a cut or placing a stitch or multiples of the two. Making a cut and placing a stitch is something that all surgeons do with reasonable ease and efficiency on the skin level. The only difference between skin and retroperitoneal surgery (including the vena cava-related tumors) is the access.
From top to bottom: Liver, Rt. colon, duodenum- head of pancreas and small bowel. (The last 3 are in a sense a complex since the fulcrum of the tree is the Superior mesenteric vessel).
Mobilizing the liver entails cutting the falciform (and round ligament), rt. triangular ligament, coronary ligament (and rt. triangular ligament)
Notes on hepatic veins control
Notes on hepatic veins control
1. In either A or B, hepatic veins control is not to be attempted before complete freedom of intrahepatic cava is achieved by ligation of short hepatic veins from all directions. The hepatic vein stumps gain much length when this is done combined by outward traction on the liver. Care is to be taken not to misidentify the main hepatic veins as a large short hepatic vein
2. Main hepatic veins are wide based, and therefore standard looping using a right angled forceps is usually not possible if not hazardous; the rt. angled forceps’ blade is never long enough to cover the whole width of them. The technique used by the author is as follows:
–Complete freeing of the cava from short hepatic veins
–An artery forceps has its back lying flat on the midline of the cava (i.e., the tip is toward the ceiling) from the caudal side and from the cranial side alternatively until it shows up from the other direction. This necessitates observing a characteristic notch that appears on the caval wall at the central tendon side demarcating the boundary between the rt. and the middle hepatic vein marked by an arrow in Fig. 32.2b lt. This notch guides the placement and direction of the aforementioned artery forceps. As the artery forceps aims at coming out from the other side, its tip should stay directed to the ceiling till showing up again after traversing the full length of the hepatic vein entry to cava. This avoids faulty outwarding through the hepatic vein wall itself which is thin and compressible and might give the operator an impression that it is a connective tissue band specially when flattened against the artery forceps or indeed the rt. angled forceps (Fig. 32.3)
3. Lt. hepatic vein isolation requires working from the left-hand side and division of the lesser omentum in order to gain access to the area of concern (Fig. 32.4). It might require as well clearing off hepatic parenchyma that usually covers part of the lt. hepatic vein entry to cava
Cranial as opposed to lateral flipping of small bowel is to be used when exposure of the aorta and cava is required to take place at the same time and in the same field. In these occasions, cranial flipping might be better (Fig. 32.6).
Options for small bowel
Options for small bowel
This is a ladder of options according to degree of exposure required
3. Tenting: In which root of mesentery released yet coecum stays in right iliac fossa, and the surgery takes place underneath the small bowel and rt. colon mesentery (Fig. 32.7)
Though mobilizing the organs is the first manual step, it is preceded by a mental one, a step that the author describes as step zero. This step is done on the scans in which the surgeon, with eye on the scans, defines the circle of interest which is the field of surgery, the field that needs to be cleared to start dissection of the tumor. This circle will be the surgeon’s world for the surgery of resection, but one has to define it in the first place, and the advice here is to delineate a circle that encompasses the tumor range and a “bit more” in every direction.
This “bit more” is a rim of anatomical field all around the tumor in which the surgeon will patrol looking for blood vessels and ducts getting in and out of the field of the tumor to identify and sling. On top of which undoubtedly is the proximal and distal control of the vena cava. This step of patrolling and slinging comes as the second phase of the surgery after the organ mobilization phase. When completed, and only when it is, the surgeon can now “recall” that he is here to resect a tumor and pay attention to the tumor-vena cava complex.
Now the surgeon has the cava adherent to the tumor and the tumor adherent to the retroperitoneal structures and posterior abdominal wall, so where to start?
It is usually tempting to many surgeons to go straight to the cava to take off the tumor and breathe the sigh of relief and as well decide “resectability,” for some will abandon the procedure if the vena cava is inseparable from the lesion.
The answer to the question “where to start?” is fairly similar to the situation of examining the abdomen in clinical rounds. You ask where the pain is and you start at the farthest point palpating the abdomen leaving the quadrant of pain till the end.
The tumor is to be mobilized laterally first with complete disregard to the cava. Only when the tumor and cava are mobilized as one complex one can start handling the cava, and this marks the fourth and final phase of the surgery, the phase of handling the cava.
Subadventitial dissection of the cava off the tumor
Resection of the tumor-cava complex and replacement by a graft
Opening the cava to excise a tumor thrombus
Even for surgeons who are making a decision to abandon the procedure if the cava is inseparable from the tumor, the author would recommend leaving the cava till the end. One will be amazed how friendly is this badly reputed organ will be when the procedure is done in this order. The surgical team will find a cooperative organ tolerating much traction, dissection, and repairs when needed, all enabling dissection of the cava that would, in other wise order, have seemed inseparable from the tumor.
The technique of dissection of the vena cava off the tumor entails using No. 15 blade lying flat. As soon as a window can be opened anywhere along the caval segment in question, a sling is to be passed round the cava and pulled in different directions including upward. This sling retraction enables maneuvering the cava here and there giving access to its different facets including the posterior one, and hence dissection can proceed and the short-stumped tributaries viewed and get a bit of length for control and division.
The sling belongs to the main operator’s dominant hand with a dissection tool in the other being it a blade, a scissors, a dissection forceps, a sponge on a stick, or a Poole Suction Tip with the shield removed. Poole Suction Tips with holes very close to the tip are favored when suction tips are used for dissection. The proximity of holes to the tip makes them suck minute amount of blood rapidly and hence clearing the field for dissection. For scissors, a standard Metzenbaum is one friendly instrument. It is of value to add to the set a round-tipped Reynolds scissors of variable lengths.
An experienced assistant would have forceps in his non-dominant hand and suction tip in the other if the main operator is not holding it. Otherwise another forceps or counter traction by a small swab should be the case. The suction in whoever’s hand is not only for sucking but also for teasing the tissues trying to open up the plane.
32.3 Remarks, Adjunctive Techniques, and Special Situations
Tumor embolism and the use of preoperative IVC filters
Positioning of the patient
Role of table-mounted retraction and magnification
The difference between lateral dissection and posterior dissection
Vena cava clamping
Vena cava grafting
Inviting an old technique: vena cava compartmentalization
184.108.40.206 Tumor Embolism and the Use of Preoperative IVC Filters
Particularly for the case of intraluminal tumor thrombi, the risk of embolism is of concern. Early proximal clamp is always advisable. The use of preoperative IVC filters is another option. These are better to be retrievable, and there needs to be a space of at least 4 cm before the cavo-atrial junction to enable deployment of the filter. Transfemoral access routes are strictly prohibited for the risk of embolism as a result of manipulation of the thrombus by the passing endovascular tools.
The authors have dealt with four types of intraluminal tumors in the cava and some other veins, namely, Wilm’s tumor, sarcomas of different kinds, renal cell carcinomas, and thyroid carcinoma.
Out of the four, the renal cell carcinoma has been found to be very liable to detachment, and hence early proximal clamping is mandatory. The other three has been found friendlier. Particularly with Wilm’s tumor, thrombi tend to be adherent to the wall by synechia which probably arise after chemotherapy. Sarcomas have been found to be firm and compact and rubbery. The initial touch of the thrombus informs about its firmness, attachment to the wall, and coherence. This should indicate the need for early proximal clamping.
220.127.116.11 Positioning of the Patient
A roll underneath the site of surgery is the standard for abdominal surgery. When surgery includes resection of a tumor, surgeons tend to put the roll underneath the equator of the tumor. The recommendation here is, again, to ignore the main bulk of the tumor and its equator. The roll is best put underneath the part of surgery that is farthest or critical in access. In the case of vena cava-related tumors, this is usually the upper pole of the field of surgery rather than the equator of the tumor. This is the point of proximal control.
18.104.22.168 Incision (Fig. 32.10)
Bilateral Transverse with Supraumbilical Midline Extension
It gives very good vertical access as well as horizontal one where the surgeon can approach the cava from top view or from sides with side rotation of the operating table and the surgeon sitting on an operating room stool. This helps much in lateral and posterior dissection of tumors, a note on which will be given later.
Midline With or Without Transverse Extension
Obese patients whom their fat is extra-abdominal are far friendlier than what one would expect. The weight of the abdominal wall fat seems to make it to fall off to the sides offering an unexpected access from the midline incision only.
Any of the Above 2 with a Median Sternotomy
Any of the above 2 can have a median sternotomy (partial or complete) as an extension according to ease of access to suprahepatic cava keeping a low threshold to do so. Its merits supersede morbidities. Patients with narrow subcostal angle or those with a decubitus characterized by big anteroposterior diameters at the level of epigastrium will probably require it for suprahepatic control. Should one be in a position to do a suprahepatic cava control for other reason than a large neoplasm, he would find this readily accessible without a sternotomy. And probably he will judge the recommendation of sternotomy as unnecessary or overdoing. This does not apply when a big tumor is inside especially for rt.-sided upper quadrant tumors which pushes the liver cephalad preventing downward pull on the liver even when mobilized. This downward pull is pivotal in the access. In addition, the process of liver mobilization itself can be very difficult, time consuming, and bloody when tumors in these locations are accessed without a thoracoabdominal incision. The authors choose the sternotomy out of the thoracoabdominal incisions options for its more suitability for the task and its lower morbidity including pain control and lesser respiratory complications.
In conclusion, the midline supraumbilical component of the wound and the rt. transverse component are the most mandatory and extendable. Therefore, one of them is favored for initial exploration. Should more access be needed for exploration the other is to be added. At this point one can decide—according to the lower limit of tumor—whether to extend the midline downward or do a left transverse extension. The median sternotomy is the same in either case.
One should not extend the rt. transverse to the lt. side until the lower limit is settled because this lt. side extension is a giveaway of the chance to extend the midline caudally.
22.214.171.124 Role of Table-Mounted Retraction and Magnification
There might be an exception for the abovementioned near mandation of the use of table-mounted retractors which in case of huge tumors stretch the abdominal wall. The latter falls off the tumor as soon as the abdomen is opened facilitating retraction. The choice of the table-mounted retractor and its positioning need to take into account the possible need for a sternotomy. They need to be placed from the beginning of surgery to allow this to happen swiftly when needed without disturbing the whole setup. One does not have to place them all away from the whole chest field though, for one will not be operating in the cephalic part of the chest. What is required is just a draping and positioning that allows the passage of the sternal saw to make the cut.
Combining the usage of two different table-mounted retraction systems might be some surgeon’s choice, for example, a combination of a cable winch retractor for the costal margin and a Bookwalter or Omni-Tract for sides, caudal and visceral retraction. The cable winch retractor has a supreme performance in costal margin. As well, it offers ample space underneath to open the chest when needed. The Bookwalter and the Omni-Tract take on the side and caudal retraction as mentioned. It is therefore up to the surgeon and the availability of equipment.
One method for side retraction of abdominal wall is the use of the Finochietto chest wall retractor. This can be used instead of the standard Balfour retractor designed for the purpose. The Finochietto has a wider span and therefore suitable for midline incisions in subjects with big decubitus. The ones with fenestrated blades are favored as these fenestrations enable passing a stitch through them that anchors the blades to the abdominal wall to prevent its slippage from the abdominal wall edge.
As for magnification, though the cava is a gross structure and so is every structure in the field of vena cava-related tumors including the tumor itself, though this is the case, yet the author recommends the use of 2.5× magnifying loupe for most of the length of the surgery. Though structures are gross, yet it is not structures that one is after while using the loupes; one is after the tissue plans. The use of magnification helps much in defining tissue plans to desheath the cava and loop around the tributaries in proper planes with right angled forceps. During this looping one does not see the whole length of process of looping. The reliance here is on that the instrument has started in the proper subadventitial plan and therefore it is assumed that it will continue in it till the tip shows up again from the other side. This makes this proper start very important. Magnification is an important adjunct to this proper start.
126.96.36.199 The Difference Between Lateral Dissection and Posterior Dissection
The aforementioned technique should be done with no hesitation. Merits far supersede cost in the given situations. Attempts to preserve both structures are a waste of time, blood, and effort of the patient and the team.
For tumors with adequate tissue planes, lateral dissection progresses seamlessly to the posterior dissection as the surgeon pulls on the tumor. Tumors with extensive desmoplastic reaction do not follow this. The lateral dissection is difficult and so is the posterior dissection. The lateral dissection does not take the surgeon seamlessly to the posterior one. In addition, they both will require too much sharp dissection and cautery. Tissues turn to sort of a “multilayered clothing” blending in with surroundings, and hence they require handling and cutting more or less like a parenchymatous organ harboring a tumor inside it that you cannot avoid cutting through it.
If the tumor is infiltrating the posterior abdominal wall laterally, i.e., the musculature not the vertebral column, here lateral dissection might be very bloody and requiring too much traction on the tumor risking their rupture which is a thing to be avoided at any cost. To avoid this, it is highly recommended to change the position of the patient from supine to lateral position while doing the lateral/posterior dissection. The time and effort consumed to do so is a very good investment indeed and should not be refrained from.
188.8.131.52 Vena Cava Clamping
Clamping of the vena cava can have some significant hemodynamic effects. An already compromised lumen should lessen such effects. Infrahepatic clamps are almost systematically tolerated without any specific preparation. Suprahepatic clamps on the contrary need special consideration. A test-clamp should be put on the proximal control and the operation is to be paused for a while. When the anesthetist reassures that the clamp is well tolerated in terms of hemodynamic effects, handling the cava can then start. If signs of hemodynamic instability are observed, the clamp is to be released until necessary measures are implemented, and the test is repeated.
Measures to enhance tolerance of this clamp are known to anesthetists. Before test clamping it might be helpful to put the operating table in a head-down position for few minutes in order to allow pooling of the blood in the upper half of the body.
Unless readily accessible and clear, it is recommended to defer the top control of the cava after the bottom control and the Pringle’s maneuver. In case the vena cava is injured during dissection in this relatively tight space, there will be an opportunity to lessen the bleeding by cross-clamping of the distal cava as well as occlusion of the Pringle’s maneuver. If the repair can be done in these conditions, then well and good. If not, the hole is to be compressed and the liver returned back to rest on it. After which a sternotomy is to be performed and the intrapericardial cava is to be clamped. This is to be followed by returning back to the hole to get the necessary repair done.
Though total cross-clamps of suprahepatic vena cavas will eventually be tolerated by most if not all patients, it is to be mentioned that sometimes even the mere traction on the looped-around hepatic veins might cause considerable hypotension. Should hypotension happen unexplainably during surgery, it is recommended to have a look at the slings looping round the hepatic veins. Even when they look innocent, they might need to be loosened completely or even removed, and the liver is to be returned back to the abdomen in the normal position.
184.108.40.206 Vena Cava Grafting
Of the Threshold to Resect and Replace the Cava
In short, cavas that are easily dissectable from the tumor are to be dissected and left in place.
Adherent cavas will require harsh manipulation. They are not expected to perform better than the graft after this harsh manipulation; they will probably occlude anyway. In this case if there is a technical advantage of removing the cava in terms of blood loss or access and safety of dissection of other more important structures, namely, aorta and its branches, the surgical team is then advised to keep a low threshold to cross-clamp the cava and resect it. Please see section for lateral and posterior dissection.
Of the Best Caval Replacement Conduit
For small defects requiring patch graft, pericardial autografts serve as a good option as well as prosthetic grafts.
For full-circumference segment replacement, the body of literature present in the topic supports that PTFE is the conduit of choice. However, it is to be mentioned that not much Dacron grafts have been used for the purpose in the first place; those who have been used have performed as good.
In conclusion, if PTFE is available then it is reasonable to give it priority. However, if it is not available Dacron can be used instead.
The need for ring enhancement has been recommended by authors justified by the low pressure in the cava. However, it is to be remembered that the native cava is even of a more pliable wall than any graft. Therefore, ring-reinforced grafts are not to be considered a must unless for any reason the surgeon judges the presence of anatomical changes that will obviously compress the cava. An example of this is replacement of intrahepatic vena cava that required complete freeing from the central tendon.
Of the Implantation of a Single Renal Vein in the Graft
Caval resections above the level of renal veins would entail temporary interruption of renal vein and reimplantation into the graft (Fig. 32.8b rt.). This interruption might take time and is liable to postoperative thrombosis.
Assessment of efficiency of collateral venous circulation
Assessment of efficiency of collateral venous circulation
1. Cross-clamping test and observing urine output, turgidity, and color
2. Doppler assessment during cross-clamping
3. Venous stump pressure
It is important to note that, while doing the assessment of efficiency of the collateral venous circulation of the kidney, the kidney is not to be mobilized or dissected for the purpose of better visualization. It should and it is always possible to do so while the kidney is still in place and not dissected. Mobilization and dissection can lead to disturbance of collaterals.
Of the Need for Muscle Cover for the Repaired Cava
The field after resection of these tumors is usually peritoneum-void leaving the repaired cava in contact with bowel. None of the authors who investigated the topic have reported the use of routine muscle cover. None reported enteric-caval fistulas as well.
Based on the author’s personal experience as well as others, perhaps it is reasonable to say that if there is no concomitant bowel anastomosis, then there is no need for routine muscle cover.
220.127.116.11 Inviting an Old Technique: Vena Caval Compartmentalization
Nothing in the surgeons’ pocket to guard against thrombosis of the harshly treated cavas other than anticoagulation and hemodilution. The use of anticoagulation should be balanced against the risk of bleeding specially in the first postoperative day after a surgery with an extensive raw area.
32.3.2 Adjunctive Techniques
Shunting and intraoperative balloon occlusion
The use of cell savers
In situ perfusion and ex vivo surgery
18.104.22.168 Shunting and Intraoperative Balloon Occlusion
Shunting the vena cava is a procedure that is usually required for trauma setting rather than for resection of tumors. Its application is particularly of usage for retrohepatic vena cava and intrahepatic vena cava. Shunting is not a maneuver to stop the bleeding. Vascular exclusion of the liver is the procedure that is intended for lessening of the bleeding; shunting is an adjunct to the vascular exclusion that allows flow from the lower body to reach the rt. atrium during the vascular exclusion. It is used when the vascular exclusion results in significant hypotension. It maintains a decent venous return for a patient who has already lost a significant amount of blood. The aforementioned scenario is not the usual case for vena cava-related tumor surgery. However, still it might happen. The options for shunting are veno-venous bypass or direct shunting by cuffed endotracheal tube of appropriate size [5, 6].
Balloon occlusion on the other hand is a method to stop bleeding. A Moore-Pilcher balloon is inserted through the femoral vein and advanced to the retrohepatic vena cava. Inflation of the balloon occludes the cava as well as the entry of the hepatic veins .
If inadvertent trauma to cava occurs or is expected, shunting might be still utilized in tumor surgery the same way it takes place in trauma.
In such a situation it is might be more accessible to introduce the shunt from a more caudal segment of the vena cava in a field with regular anatomy rather than from the rt. atrium.
It is helpful to do the vascular exclusion in the following sequence: clamping the porta hepatis first and squeezing the liver manually to push the blood out to the hepatic veins followed by caval distal control and finally caval proximal suprahepatic control.
Maneuvers to prevent air embolism in low pressure cavas
1. Direct manual sealing of the injury
2. Rush to the top control first before bottom control and porta hepatis control
3. Valsalva maneuver by anesthetist
4. Filling the field with saline solution with a rt. shoulder uptilt to prevent saline from pouring out
Signs of low pressure in cava
1. Direct measurement of CVP reflects pressure in cava if the patient is lying flat
2. Absence of profuse bleeding from caval injury
3. Brisk venous pulsations in the vena cava
22.214.171.124 The Use of Cell Savers
As is the case with surgery for any form of malignant disease, the use of cell savers is controversial. Investigators found that the probability of presence of malignant cells in the scavenged blood is relatively high [7, 8].
Two integral questions are still not completely answered: do these cells have the capacity to become metastases? If they do, is this risk more than the risks associated with allogenic blood transfusion? It is out of the scope of this text to discuss this literature in thoroughness. This has been tackled comprehensively in transfusion literature .
Since the issue is not finally resolved by transfusion specialists, surgeons therefore need to make their choice. What relates here is that in very few occasions the use of cell savers will be found necessary should the abovementioned strategies be entertained. It might be helpful to have it in the operating room for very special situations or for use after taking the tumor out. The use of cell savers while the tumor is still in is a matter of judgment and choice of the operating team which entails knowledge of the pathology, natural history of the disease being handled, and indeed the patient and his preferences. It will be a choice between permitting blood loss with its consequences—particularly the need for allogenic transfusion—in one side and the risk of permitting malignant cells of an unknown potential to get through to the blood stream.
126.96.36.199 In Situ Perfusion and Ex Vivo Surgery
Ex vivo resections are indicated for hepatic segment of vena cava. They entail complete extraction of the liver altogether with the IVC and indeed the tumor followed by bench surgery. This will require liver wash by an organ preservation solution (e.g., HTK solution) and cooling for the length of bench surgery. This technique has been more widely used and described by authors involved in management of Echinococcus granulosus infestation of the liver than in patients with malignancy in general. They reported liver bench time of 360 min well tolerated by the liver [10, 11, 12].
An alternative is in situ perfusion; in this technique only a caval segment is divided proximal and distal and the liver extruded from the abdomen yet the porta hepatis is left uncut and used—while in place—to flush the liver with preservation solution which is flushed out of the liver through the cut caval ends and sucked out of the field. It obtains a bloodless caval and liver dissection along with a better access to hepatic veins confluence area. After resection, these can be replanted in the native cava or to a graft according to the situation.
Ex vivo resections for tumoral surgery have been utilized by some authors with promising results .
The author would see ex vivo surgery as the future of cancer surgery not only to decrease blood loss and improve accessibility but also there might be an oncological advantage for this technique. Most of retroperitoneal resections entail dissection of important structures. Ex vivo surgery will enable these dissections to be done on the bench, and hence minimizing tumoral spillage should rupture or capsule breaches occur while trying to dissect intimate important structures.
32.3.3 Special Situations
Off-pump excision of cavo-atrial junction thrombi
Advocating staging and multiple sittings surgery: merits and philosophy of
188.8.131.52 Off-Pump Excision of Cavo-atrial Junction Thrombi
Division of the central tendon of the diaphragm longitudinally from sternum to few millimeters above the suprahepatic vena cava cut then encircles the cava leaving a cuff of central tendon on the caval wall.
This cut will lead the surgeon to the pericardial cavity seamlessly without much awareness of cutting the pericardium as a separate layer owing to the adherence of the pericardium to the central tendon in this area. The heart is protected from injury by cutting the central tendon-pericardium in the same manner that one cuts the peritoneum while entering the abdomen, pulling on a small bit between two artery forceps and making a small snip till entry takes place. This can be started in the sternal side of the cut or even better halfway between the sternum and cava. The surgeon should be able to examine the span of the presumed cut and feel where the heart pokes the least while pulsating, and this spot is probably a favored spot for making the entry snip. The region near the cava is better avoided for the initial entry as the central tendon here fans and merges with cava and will make entry to the pericardial sac awkward.
Ligation of inferior phrenic vessels.
Freeing the cava posteriorly from the crus of the diaphragm (described earlier).
A low threshold to perform a sternotomy with or without manubriotomy.
184.108.40.206 Advocating Staging and Multiple Sittings Surgery: Merits and Philosophy Of
One thing about lengthy surgeries and surgeries that entails hemodynamic shifts is that they require a patient with a good physiological reserve. Several methods in medicine are in use to preoperatively assess the physiological reserve of different organ systems in a rather objective way.
In any surgery, patient’s physiological status gets monitored minute by minute. The monitors in current practice offer you a panoramic view of this minute, yet they do not offer an eye on integral questions: “How much of the aforementioned physiological reserve is in action to offer the figures on the monitor? How much is still left in the reserves? For how long will they be able to do the required compensation to keep the physiological figures the way they are on the monitor?”
For instance, a mobile phone with a battery full will open up and do the call. When only 4% charge; it will still open up and do the call. Only when the call lasts long will the difference between the two shows up. One will continue and the other will shut down in the middle of the call.
We do not have the “% of battery charge” display in any medical monitor, and therefore it is sometimes difficult to tell when will the physiological reserve “shut down.” We only have our experience with these kinds of procedures correlated to some rough parameters like age range and preoperative assessment abovementioned. Simple factors like inadequate thermal control inside the O.R. can drain a patient’s reserve far faster than expected.
Most of vascular and cardiac surgeries are “one go” surgeries in which you cannot but have it all in one sitting.
The case for resection surgery in oncovascular practice is different. The strategy abovementioned allows staging of the procedure in more than one sitting. It is an approach in which one can pull out in the middle of it—say after the first two phases—in one sitting and defer the others a week later. One other way of drawing the line between the sittings is the use a certain time interval for the sitting. A range of 4 h of anesthesia and operative time in these surgeries is a good landmark after which the wounds are closed in an extra hour and the patient transferred to the ward or ICU. The author recommends as well that the team takes a break in the middle of the sitting, an “obligatory” break in a sense.
By the author’s direct observation, patients have been explored up to 10 days after the initial sitting, and the field was as exact as was left and even clearer. The concern about getting adhesions in such an interval is not true.
Add to this the value of giving the surgical team an opportunity to custom a more detailed plan to the second sitting after having the opportunity to acquire the givens learned in the first.
It is reasonable to assume that if the team is coming out of the surgery drained, then probably the patient is in jeopardy. An unnecessary one indeed, given the opportunity to stage the surgery. Loosing such an opportunity is such a waste.
There is nearly no cost paid for such staging. Proper information fed to the patient about this plan obviates the inconvenience of having to do two or three surgeries. It is all about anticipation. When anticipated it is well accepted.
It is not about doing “a heroic” surgery; it is about making “a heroic” surgery regular.
This has been the author’s practice in multiple occasions. It has never been regretted. What has been regretted—in fact—is not doing so, when it has been listened to the monitors portraying that the patient’s physiology is doing well and that the operation can carry on.
To make this clearer we all know that the adrenal gland is critical in stress. Its store of adrenaline and cortisol is key in these situations. As well, the liver glycogen is the source of energy. Current monitoring devices and techniques offers absolutely no idea about how much of these have been used and how much is left. This is a frontier to anesthesia and critical care medicine indeed.
In between the sessions, it is advisable to institute TPN. This should supply the building blocks for the reserves that one wishes to replenish.
32.4 Critical Note on Postoperative Care and Specific Complications
Anticoagulation has been commented on earlier in the section “Inviting an old technique: Vena cava compartmentalization.” Hemodilution and hydration are as relevant as anticoagulant drugs and should be sought with focus. Hematocrit is to be kept between 25 and 30%. Blood transfusion should be kept to the minimum need.
The standard monitoring applies. Add to this a specific requirement.
For tumors that require dissection around the superior mesenteric artery (SMA) and in pediatric population who require “mobile evisceration” of the small bowel in the manner described, the occurrence of superior mesenteric artery thrombosis is a possibility. It is a deadly pathology and somehow silent. It does not necessarily reflect on clinical and vital signs with the gravity that calls for immediate exploration. Serum lactate has to be monitored closely with a low threshold for exploration. It is critical therefore to keep the patient volume replaced properly to avoid conflicting interpretation of high serum lactate and metabolic acidosis. These will commonly be attributed to general hypoperfusion. A well-perfused patient who still has acidosis and high lactate is one who is harboring a locally ischemic tissue somewhere in his body. The abdomen is a high-profile suspect.
When “mobile evisceration” of small bowel is utilized, it might be of value to stitch back the rt. colon to the paracolic gutter and the root of small bowel to retroperitoneum to prevent twisting over the SMA now acting as the only support.
The use of monitoring ileostomy (closed loop) for the first 48 h is to be considered in situations where SMA has been handled roughly.
It is left to reader to place these adjuncts as appropriate guided by (1) magnitude of bowel mobilization and SMA dissection and (2) efficiency of postoperative hemodynamic management and monitoring in each given setup.
This complication has been encountered by the author in pediatric population. The message is that the presence of a background disease in the vessel is not a necessity at all. Still in healthy vessels an eye has to be kept and the diagnosis entertained.
32.5 Perioperative Mortalities and Oncological Outcome
32.5.1 Perioperative Mortalities
The author’s experience with the application of the abovementioned strategies and techniques is given here. These series are not all published to the moment. The results are given here to draw some light to the perioperative outcome. Sixty-five patients in different centers have been managed, 35 of which were vena caval thrombi and 30 had centrally located retroperitoneal tumors encasing either cava alone or cava and aorta. One of the former 35 died. Three of the latter 30 died perioperatively which makes a perioperative mortality rate of 6.1%. Significant morbidities include a single patient with postoperative renal vein thrombosis and ATN that resolved with exploration, thrombectomy, and supportive medical treatment without the need for dialysis.
32.5.2 Oncological Outcome
Each of the case reports and series present in literature encompass a variety of tumors in terms of anatomical origin, stage, and histopathology [1, 2, 16, 17, 18, 19, 20, 21, 22, 23]. It is not applicable therefore to release a survival rate for the entity “vena cava-related tumors.” What brought them together is the need for application of a unified technical approach. Each of which is expected to follow—in terms of survival—the same figures that are expected for their counterparts of the same histopathology and tumor biology, etc.
For instance, a neuroblastoma encasing the cava will follow the same rules that govern survival in neuroblastoma in general which is, in this occasion, the risk stratification in common use putting into effect an interplay between five different factors that includes tumor stage, N-myc amplification, and others.
Should the decision to operate or not is to be based on the expected oncological outcome; this will need to be made patient by patient with proper patient counseling.
This abovementioned concept has been put to test and investigated by authors in the field of pancreatic adenocarcinoma. Matched results have been found when patients who required arterial resection along with the pancreaticoduodenectomy are matched to retrospective controls who did not require vascular resection .
32.6 Reproducing the Service and the Making of the Oncovascular Surgeons and Service
In a dedicated future publication, the author intends to address this topic in detail. For now, a note on the basic concepts that will be introduced is going to be mentioned and these are:
First: This is a hybrid technique between oncology, vascular, microvascular, and transplantation surgeries.
Second: The system proposed to produce these oncovascular surgeons is intended—contrary to presumption—not to be labor intensive or extended over a long duration. It is intended to be an economic model of surgical education and “training.” Our current models are wasteful somehow, and it is to be admired that our medicine is still incomplete, and therefore we have to find a way to get people to learn it fast and economically to give them space, energy, and fund to look for real breakthroughs and look after their social life. That is what medicine is all about, to get people back to their social life healthy, isn’t it? Medical practitioners are part of this.
This is a unified approach to retroperitoneal tumors involving central structure in the abdomen, namely, cava, aorta, and their tributaries and branches.
The procedure passes through four phases in a particular order.
The phases put in this sequence allow staging, decrease blood loss, and enable management of different technical situations being it contact, infiltration, encasement, or intraluminal tumoral extension.
Posterior dissection might require change of position of the patient.
Posterior dissection might require cutting the cava, flipping it, and anastomosing it after resection.
No need for cell savers in most cases.
Tumors up to cavo-atrial junction can be removed off-pump.
When liver resection is required, ex vivo resection or in situ perfusion can be used.
- One will never regret:
Staging the procedure
Bigger access, particularly sternotomy
Caval resection and replacement
It is not about doing a heroic surgery; it is about making a heroic surgery regular and reproducible in different setups.
- Three points are yet to be made sharp in the future research:
How safe or unsafe are cell savers
For now use to the minimum indications.
Minimum parameters that indicates the efficiency of the collateral venous circulation of the kidney
For now Doppler by a kidney transplant radiologist is the current best option.
Oncological outcome for specific tumor types
For now base decisions on the results of their counterparts in other anatomical locations.
The author would like to thank Dr. Hussein Khairy for his integral role in the development of the author’s oncovascular surgery practice.
Thanks to Mr. Mark Tyrell for his key contribution in providing the concept of “vena cava-related tumors” and for his pushing forward to publish it.
Thanks to Mr. Morad Sallam for the time he offered providing opinion, liaising, and facilitating the publication.
Thanks to Mr. Mohamed Shahm, Mrs. Heba eldeeb and Ms. Anna Boriak for their efforts doing the diagrammatic representation.
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